SEA of Delaware SEA245 SEA 245 MF/HF DSC Marine Radiotelephone User Manual MARCH 18 FIRST DRAFT

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Document ID	152621
Application ID	am+7vaUturVca0BNhfn0AQ==
Document Description	sea245 preliminary users manual
Short Term Confidential	No
Permanent Confidential	No
Supercede	No
Document Type	User Manual
Display Format	Adobe Acrobat PDF - pdf
Filesize	32.59kB (407429 bits)
Date Submitted	2001-05-31 00:00:00
Date Available	2001-09-06 00:00:00
Creation Date	2001-05-31 10:05:07
Producing Software	Acrobat Distiller 4.0 for Windows
Document Lastmod	2001-05-31 10:05:41
Document Title	MARCH 18, FIRST DRAFT
Document Creator	Microsoft Word 8.0
Document Author:	SEA INC.

FIRST DRAFT 10-7-99
V1.01 4-10-00
V1.02 10-20-00
V1.03 12-1-00
V1.04 2-2-01
V1.05 5-31-01
SEA INC OF DELAWARE
PRELIMINARY MAINTENANCE MANUAL
MF/HF SSB GMDSS RADIOTELEPHONE/DSC
CONTROLLER
MODEL SEA 245
(c) Copyright 2001
SEA, Inc.
All rights reserved.
SEA, Inc.
7030 220th St. S.W.
Mountlake Terrace, Washington 98043
(425) 771-2182
FAX: (425) 771-2650
**IMPORTANT**
NOTICE TO INSTALLERS
------------------------------------------------------------------NOTE: The safe compass distance for this equipment (As defined in Paragraph 29 of
IEC Publication 92-101, Third Edition):
SEA 245 SINGLE SIDEBAND TRANSCEIVER = 2.0 meters
-------------------------------------------------------------------
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TABLE OF CONTENTS
GENERAL INFORMATION .............................................................................................................................. 1-1
1.1
1.2
1.3
1.4
1.5
OPERATION ......................................................................................................................................................... 2-1
2.1
2.2
2.3
2.4
MOUNTING THE TRANSCEIVER..................................................................................................................4-1
A TYPICAL INSTALLATION ..........................................................................................................................4-1
THE TRANSCEIVER UNIT REAR PANEL CONNECTION AND FUSES..................................................4-1
FUSING ...............................................................................................................................................................4-4
THE GROUND CONNECTION ........................................................................................................................4-5
THEORY OF OPERATION ................................................................................................................................ 5-1
5.1
5.2
5.3
5.4
5.5
5.6
5.7
GENERAL ...........................................................................................................................................................3-1
SEA 245 FREQUENCY LISTING .....................................................................................................................3-2
CAUTION! FREQUENCY TOLERANCE.................................................................................................... 3-47
SETTING THE TRANSMITTER FREQUENCIES....................................................................................... 3-48
INSTALLATION ................................................................................................................................................... 4-1
4.1
4.2
4.3
4.4
4.5
WARM UP CAUTION .......................................................................................................................................2-1
FRONT PANEL CONTROLS ............................................................................................................................2-1
PROPAGATION .................................................................................................................................................2-1
BANDWIDTH LIMITATIONS .........................................................................................................................2-2
MODE AND FREQUENCY CONTROL ........................................................................................................... 3-1
3.1
3.2
3.3
3.4
DESCRIPTION ...................................................................................................................................................1-1
EQUIPMENT FURNISHED ..............................................................................................................................1-2
TRANSCEIVER UNIT SPECIFICATIONS ......................................................................................................1-2
MECHANICAL INFORMATION .....................................................................................................................1-2
ELECTRICAL SPECIFICATIONS:...................................................................................................................1-2
GENERAL ...........................................................................................................................................................5-1
THE RECEIVER .................................................................................................................................................5-1
THE TRANSMITTER ........................................................................................................................................5-7
THE MASTER CLOCK OSCILLATOR AND SYNTHESIZER SYSTEM ................................................. 5-11
THE 2187.5 KHZ MONITOR RECEIVER...................................................................................................... 5-14
THE POWER SUPPLY CIRCUIT .................................................................................................................. 5-18
THE MAINBOARD CONTROLLER AND DSP PROCESSORS ................................................................ 5-21
THE SEA 245 FRONT PANEL/CONTROLLER SYSTEM ........................................................................... 6-1
6.1
6.2
GENERAL ...........................................................................................................................................................6-1
THEORY OF OPERATION ...............................................................................................................................6-1
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LIST OF FIGURES
2.1
FRONT VIEW OF SEA 245............................................................................................................................... 2-1
5.2.1 RECEIVER BLOCK DIAGRAM ....................................................................................................................... 5-2
5.3.1 TRANSMITTER BLOCK DIAGRAM .............................................................................................................. 5-6
5.4.1 SYNTHESIZER BLOCK DIAGRAM .............................................................................................................. 5-12
5.5.1 2187.5 KHZ MONITOR BLOCK DIAGRAM ................................................................................................ 5-14
5.6.1 POWER DISTRIBUTION BLOCK DIAGRAM ............................................................................................ 5-17
5.7.1 MAINBOARD CPU AND DSP BLOCK DIAGRAM .................................................................................... 5-20
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1
1.1
GENERAL INFORMATION
DESCRIPTION
The SEA 245 is a compact, all solid-state, 150-Watt PEP, MF/HF SSB
Radiotelephone Transceiver/DSC Controller. The SEA 245 is Type Certified for
use in Sea Area A2 GMDSS stations and it suitable for use in any general purpose
MF/HF radiotelephone application.
The SEA 245 covers the 1.605 to 29.999 MHz frequency range with channel
restrictions which are determined only by the rules regarding the appropriate radio
service. As normally programmed, the SEA 245 frequency memory contains ALL
normally assigned ITU VOICE and TELEX channels and has space available for
any additional channels which might be desired.
The SEA 245 is fully synthesized with 10 Hz resolution and the channel frequencies
are controlled by a precision crystal housed in a temperature-stabilized enclosure.
The transceiver is designed to operate from a 24-Volt power system. Grounding the
chassis of the SEA 245 will NOT ground either supply voltage rail. The SEA 245 is
normally configured as a conventional locally controlled radiotelephone with a
backlit 19 key keypad and large backlit LCD graphics display. The output
impedance is 50 ohms and the radiotelephone is certified for operation directly into
suitable 50 ohm antenna systems in the 2000 kHz to 27.5 MHz frequency range.
When operation in the 1605 to 2000 KHz frequency range is required (FCC pp
80.905 and pp 80.909 "Maritime Services; General Exemption for Small Passenger
Vessels Operated on Domestic Voyages" as amended June 19, 1991), it is
MANDATORY that the SEA 245 be operated with either the companion SEA 1635
antenna tuner or the standard SEA 1612C or SEA 1631 antenna tuners.
The usual MARINE applications will employ an antenna tuner to properly match
the antenna to the 50 ohm impedance required by the radiotelephone. For these
applications, the SEA 245 is designed to operate interactively with either the SEA
1635, SEA 1612C or SEA 1631 antenna tuners. See installation diagrams for
details on system interconnections.
The SEA 245 may also be operated from a single remote location using SEA 2450
Remote Controllers and the upgraded SEABUSS(c) interconnection provided.
The SEA 245 is also provided with an independent RS232 port which provides for
easy interconnection with a computer.
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FCCID: BZ6SEA245
1.2
EQUIPMENT FURNISHED
1.2.1
SEA 245 MF/HF Single Sideband Transceiver
1.2.2
Transceiver Mounting Bracket
1.2.3
Microphone and Microphone Clip
1.2.4
Power Connector
1.2.5
SEABUSS Connector, 9 pin PHOENIX type, female
1.2.6
Accessory Connector, 14 pin PHOENIX type, female
1.2.7
SEA 245 Operator's Manual
1.3
TRANSCEIVER UNIT SPECIFICATIONS
1.4
MECHANICAL INFORMATION
1.4.1
DIMENSIONS:
(HEIGHT-WIDTH-DEPTH)
In: 3.9 x 10.5 x 10.5
mm: 99 x 265 x 265
1.4.2
WEIGHT:
Lbs: 10
Kgs: 4.5
1.5
ELECTRICAL SPECIFICATIONS:
Type Acceptance
FCC Parts 80, 87, 90
FCC IDENTIFIER
BZ6SEA245
Frequency Range
(Tx) 1.605 - 29.999 MHz
(Rx) 0.490 - 29.999 MHz
Circuitry
Double Conversion, 45 MHz 1st IF, 40 kHz
(nominal) DSP
Operating Controls
19 Key Keypad, Volume Control
Channel Capacity
976 Marine ITU Channels in permanent
storage, 200 scratchpad channels
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Operating Temperature
-30 degrees to +60 degrees C
Frequency Stability
+ 10 Hz
Operating Modes
J3E, R3E, H3E (2182 kHz), A1A (CW), F2B
(TELEX)
Primary Voltage
24 V DC –10, +25% (21.6 to 30 V DC)
Current Drain:
Receive (Standby)
1 Amp
Receive (Full Audio)
1.5 Amps
Transmit (Average Voice)
6 Amps
Transmit (Two Tone)
8 Amps
Transmit (TELEX)
12 Amps
RF Impedance
1.5.1
50 Ohms
TRANSMITTER
Power Output
R3E, J3E 150 Watts PEP
F2B 100 Watts
LOW = 50 - 75 Watts
VLOW = 25 - 40 Watts
1.5.2
Intermodulation (J3E)
-34 dB below PEP (3rd)
Spurious Emissions
-65 dB below PEP
Carrier Suppression
-46 dB below PEP
Unwanted Sideband (@1000Hz)
-41 dB below PEP
Audio Response (J3E)
400 - 2500 Hz (@ -6 dB)
Hum and Noise
-46 dB below PEP
Tx Attack Time
≥ 15 ms
RECEIVER
Sensitivity, J3E ≥ 2.0 MHz
≤ 1 μV for 12 dB SINAD
Bandwidth, J3E
400 - 2500 Hz (@ -6 dB)
Selectivity, J3E at -1 kHz
≤ -55 dB
AGC, J3E
Fast attack, slow release, ≤ 10 dB audio level
from 10 μV to 100 mV input
change
Intermodulation
≤ -80 dB
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FCCID: BZ6SEA245
Spurious Responses
≤ -60 dB
Audio Output
4 W with ≤ 10% distortion into external 4
ohm load.
Internal Loudspeaker
2.5" round, 4 ohm, 2 Watt
Spurious Radiation
Complies with FCC, EIA
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FCCID: BZ6SEA245
SEA 245 FRONT VIEW (see separate attachment)
FIGURE 2.1 SEA 245 FRONT VIEW
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FCCID: BZ6SEA245
2
2.1
OPERATION
WARM UP CAUTION
Do not attempt to transmit until the radiotelephone is warmed up for at least 1
minute. Transmitting before the 1-minute warm-up period has elapsed can cause
violation of FCC regulations.
2.2
FRONT PANEL CONTROLS
Figure 1 illustrates the front panel of the SEA 245. The function of the individual
controls and indicators are listed below.
2.2.1
ROTARY CONTROL
One rotary control is provided. This is the ON/OFF VOLUME control. Rotating
the control clockwise from the extreme counter-clockwise position will switch the
power ON. Further clockwise rotation adjusts the receiver loudspeaker volume to
the desired level. Note that this control does NOT adjust the SEABUSS audio level.
2.2.2
KEYPAD
All of the various operating functions of a MF/HF radiotelephone and a Class A
Digital Selective Calling Controller are realized through the 19 key keypad on the
SEA 245 front panel, together with an interactive system of menus on the front
panel LCD. For more specific details regarding the operating system, refer to the
SEA 245 Operators Manual (OPR-245).
2.2.3
LCD DISPLAY
The LCD display used in the SEA 245 is an LED backlit graphics display module.
This technology provides a fully reprogrammable display that facilitates the many
different display requirements for a combination Radiotelephone/DSC Controller.
2.3
PROPAGATION
MF/HF radio signals propagate far beyond the horizon. MF frequencies (2-3 MHz)
are generally usable within 300 miles depending on the time of day, atmospheric
conditions and man-made noise levels.
The High Seas frequencies (4, 6, 8, 12, 18, 22 and 25 MHz) allow communications
over thousands of miles, again subject to the above mentioned limitations,
Interference tends to be more of a problem on the MF/HF bands than on VHF
channels.
To promote a more in-depth understanding of the vicissitudes of MF/HF
communications, SEA's "Mariners Guide to Single Sideband" (MAN-0001-001) is
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FCCID: BZ6SEA245
highly recommended reading.
2.4
BANDWIDTH LIMITATIONS
The only limitation imposed by the SEA 245 is that the desired frequency be inside
the operating range of the equipment. In practice the antenna system will have a
great deal to do with dictating the maximum allowable frequency separation. If (as
is usually the case) a companion antenna tuner such as the SEA 1635 or SEA 1612C
in used in conjunction with the usual short whip antenna, the allowable 2 MHz split
may be reduced to a few hundred kHz.
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FCCID: BZ6SEA245
3
3.1
MODE AND FREQUENCY CONTROL
GENERAL
In the SEA 245, the frequency of operation is determined through a combination of
coarse and fine tuning mechanisms. The coarse tuning system consists of the PLL
circuitry associated with the first Local Oscillator VCO. The effective loop
frequency of the PLL is 4 kHz and the first LO is preset to the nearest incremental
frequency needed to convert the desired operating frequency to 45 MHz. The
required divide-by-N number for a given operating frequency is calculated by the
control microprocessor and then loaded into the main loop PLL chip through the
microprocessor SPI bus. The fine tuning system is incorporated into the DSP
algorithm, which operates as the receiver “back end” and the transmitter "front end".
The PLL that controls the second conversion oscillator is also loaded through the
microprocessor SPI bus.
Such data as filter band, VCO band, synthesizer loads, carrier status and DSP
algorithm are calculated and stored in appropriate registers by the controller
computer, once the desired channel is entered by the operator.
3.1.1
TRANSMITTER MODE SELECTION
The primary mode of operation of the SEA 245 is in the J3E (SSB with fully
suppressed carrier) mode.
Two auxiliary VOICE modes are also provided:
R3E: SSB with pilot carrier re-inserted 16 dB below PEP.
H3E: SSB with pilot carrier re-inserted 6 dB below PEP.
J3E is the basic SSB operating mode and is used for virtually all VOICE
communications. H3E (AME) is used to provide a degree of compatibility between
old style AM and SSB systems. Present practice limits this mode to 2182.0 kHz
ONLY. R3E is primarily used to provide a pilot carrier on public correspondence
channels. Present practice ignores this mode.
J2B: TELEX operation with both internally and externally generated (AFSK) tones.
Uses J3E mode with narrower bandpass filter. Note that the internal DSC system
uses the same standard 1700 Hz subcarrier frequency as is used in the SEA 3000
SEATOR equipment.
3.1.2
RECEIVE MODE SELECTION
The SEA 245 supports J3E, R3E and H3E modes as a standard SSB (J3E) receiver.
The passband filter and AGC characteristics are tailored for SSB VOICE operation.
In the TELEX (J2B) receive mode, the passband filter is shifted to narrowband (500
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FCCID: BZ6SEA245
Hz) and the BFO offset is set to the International Standard of 1700 Hz. AGC is fast
attack, fast release.
In the CW (A1A) receive mode, the receiver passband filter is shifted to narrowband
(500 Hz) and the BFO offset is set to 1000 Hz. AGC is fast attack, fast release.
In the AM (A3E) receive mode, the receiver passband is shifted to maximum
bandwidth (4 kHz) and the received signal carrier is offset 1 kHz from the passband
center. The DSP based envelope detector provides "true" AM demodulation with an
effective bandwidth of 3000 Hz for audio recovery. This mode is useful primarily
in the reception of time signals from WWV, shortwave broadcast signal etc. AGC
is fast attack, fast release.
3.2
3.2.1
SEA 245 FREQUENCY LISTING
2 MHZ VOICE BAND
VOICE
SHIP
SHIP
RECEIVE
TRANSMIT
201
2003.0
2003.0
Ship-to-Ship, Great Lakes
202
2450.0
2003.0
KMI Point Reyes, CA
203
2006.0
2006.0
Alaska
205
2446.0
2009.0
WLO, Mobile, AL
206
2506.0
2009.0
WAH, St. Thomas
208
2030.0
2030.0
Virgin Islands, Intership
209
2490.0
2031.5
WOM, Ft. Lauderdale, FL
211
2054.0
2054.0
British Columbia WX
212
2065.0
2065.0
Ship-to-Ship
213
2079.0
2079.0
Ship-to-Ship
214
2082.5
2082.5
Ship-to-Ship Only
215
2086.0
2086.0
Ship-to-Ship, Miss. River
CHANNEL
USE
Limited Coast
216
2585.0
2086.0
KRV, Pence Playa,
WAH, St. Thomas, VI
217
2093.0
2093.0
Ship-to-Ship Only
Commercial Fish
218
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2096.5
2096.5
Page 3-2
Ship-to-Ship,
FCCID: BZ6SEA245
Ship to Limited Coast Station
219
2115.0
2115.0
Alaska
220
2118.0
2118.0
Alaska
221
2514.0
2118.0
WOM, Ft. Lauderdale, FL
WLC, Rogers City, MI
223
2309.0
2131.0
WOU-23, Kodiak, AK
224
2312.0
2134.0
WGG-53, Cold Bay, AK
225
2530.0
2134.0
KBP, Kahuka, HI,
KOP, Galveston
226
2134.0
2134.0
Eastern Canada Intership
227
2538.0
2142.0
KCC, Corpus Christi, TX
228
2142.0
2142.0
CA Intership
229
2146.0
2146.0
230
2550.0
2158.0
PJC, Curacao
231
2550.0
2166.0
VRT, Bermuda
232
2558.0
2186.0
WOO, Manahawkin, NJ
233
2582.0
2166.0
8PO, Barbados,
C6XZ, Marsh Harbor
234
2558.0
2198.0
VPN-2, Nassau Weather
236
2203.0
2203.0
Ship-to-Ship, Gulf of Mexico
238
2582.0
2206.0
WBL, Buffalo, NY
VCS, Halifax, Canada
239
2397.0
2237.0
WDV-26, Cordova
WGG-56, Ketchikan, AK
240
2400.0
2240.0
WGG-58, Juneau, AK
WGG-55, Nome, AK
241
2735.0
2290.0
242
2450.0
2366.0
245
2566.0
2390.0
246
2400.0
2400.0
247
2442.0
2406.0
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9YL, North Post, Trinidad
WOM, Ft Lauderdale, FL
WOM, Ft Lauderdale, FL
FCCID: BZ6SEA245
248
2506.0
2406.0
KMI, Point Reyes, CA
249
2419.0
2419.0
Alaska
250
2422.0
2422.0
Alaska
251
2427.0
2427,0
Alaska
252
2572.0
2430.0
WLO, Mobile, AL
254
2430.0
2430.0
Alaska
255
2447.0
2447.0
Alaska
256
2450.0
2450.0
Alaska
257
2506.0
2458.0
KGN, Delcambre, LA
258
2479.0
2479.0
Alaska
259
2482.0
2482.0
Alaska
261
2506.0
2506.0
Alaska
262
2509.0
2509.0
Alaska
263
2512.0
2512.0
FFP, Ft. Defrance,
Windward Is.
264
2545.0
2545.0
265
2527.0
2527.0
266
2535.0
2535.0
267
2538.0
2538.0
Alaska
268
2563.0
2583.0
Alaska
269
2566.0
2566.0
Alaska
270
2582.0
2582.0
Alaska
271
2590.0
2590.0
Alaska
273
2616.0
2616.0
Alaska
275
2638.0
2638.0
Ship-to-Ship
276
2640.0
2640.0
277
2670.0
2870.0
USCG Working
278
2704.0
2704.0
Ocean Racing
279
2735.0
2735.0
9YL, North Post, Trinidad
280
2738.0
2738.0
Ship-to-Ship
Alaska
Except Great Lakes and Gulf
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FCCID: BZ6SEA245
281
2782.0
2782.0
Ship-to-Ship River
WFN, Jeffersonville, IN
WGK, St. Louis, MO
WJG, Memphis, TN
282
2830.0
2830.0
283
2237.0
2237.0
284
2530.0
2815.0
285
2040.0
2040.0
286
2318.0
2318.0
287
2366.0
2366.0
288
2469.0
2708.0
289
2060.0
2798.0
290
2458.0
2340.0
291
2085.0
2045.0
NORWEGIAN
292
2048.0
2048.0
NORWEGIAN
293
2051.0
2051.0
NORWEGIAN
294
2057.0
2057.0
NORWEGIAN
302
3198.0
3198.0
Alaska Point-to-Point
303
3201.0
3201.0
Alaska Point-to-Point
304
3258.0
3258.0
Alaska
305
3261.0
3261.0
Alaska
306
3449.0
3449.0
Alaska Aero
3.2.2
Ship-to-Ship, Gulf Only
4 MHZ VOICE BAND
VOICE
CHANNEL
401
SHIP
SHIP
RECEIVE
TRANSMIT
4357.0
4065.0
USE
KMI, Point Reyes, CA
WAH, St. Thomas, VI
402
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4360.0
4068.0
Page 3-5
FCCID: BZ6SEA245
403
4363.0
4071.0
WOM, Ft. Lauderdale, FL
404
4366.0
4074.0
KGN, Delcambre, LA
405
4369.0
4077.0
WLO, Mobile, AL
WLC, Roger City, MI
406
4372.0
4080.0
407
4375.0
4083.0
408
4378.0
4086.0
409
4381.0
4089.0
410
4384.0
4092.0
WOO, Manahawkin, NJ
411
4387.0
4095.0
WOO, Manahawkin, NJ
412
4390.0
4098.0
WOM, Ft. Lauderdale, FL
413
4393.0
4101.0
414
4396.0
4104.0
415
4399.0
4107.0
416
4402.0
4110.0
WLO, Mobile, AL
KMI, Point Reyes, CA
WOO, Manahawkin, NJ
417
4405.0
4113.0
KMI, Point Reyes, CA
WOM, Ft. Lauderdale, FL
418
4408.0
4116.0
419
4411.0
4119.0
420
4414.0
4122.0
421
4417.0
4125.0
422
4420.0
4128.0
WOO, Manahawkin, NJ
423
4423.0
4131.0
WOM, Ft. Lauderdale, FL
424
4426.0
4134.0
NMG, New Orleans, LA
WLO, Mobile, AL
NMN, Portsmouth, VA, WX
425
4429.0
4137.0
426
4432.0
4140.0
427
4435.0
4143.0
428
4351.0
4060.0
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Page 3-6
WLO, Mobile, AL
FCCID: BZ6SEA245
450
4125.0
4125.0
DISTRESS
451
4146.0
4146.0
4A LTD Coast/Intership
452
4149.0
4149.0
4B LTD Coast/Intership
453
4417.0
4417.0
4C LTD Coast/Intership
454
4366.0
4366.0
Alaska
455
4369.0
4369.0
Alaska
456
4396.0
4396.0
Alaska
457
4402.0
4402.0
Alaska
458
4420.0
4420.0
Alaska
459
4423.0
4423.0
Alaska
460
4065.0
4065.0
Mississippi River
461
4089.0
4089.0
Mississippi River
462
4116.0
4116.0
Mississippi River
463
4408.0
4408.0
Mississippi River
501
5164.5
5164.5
Alaska Public Fixed
502
5167.5
5167.5
Alaska Emergency/Calling
503
5680.0
5680.0
Aero Search/Rescue
504
5472.0
5472.0
Aero Search/Rescue
505
5490.0
5490.0
Aero
3.2.3
6 MHZ VOICE BAND
VOICE
CHANNEL
601
SHIP
SHIP
RECEIVE
TRANSMIT
6501.0
6200.0
USE
NMN, Portsmouth, VA
NMG, New Orleans, LA
MNA, Miami, FL
602
6504.0
6203.0
603
6507.0
6206.0
604
6510.0
6209.0
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Page 3-7
FCCID: BZ6SEA245
605
6513.0
6212.0
606
6516.0
6215.0
607
6519.0
6218.0
608
6522.0
6221.0
650
6215.0
6215.0
DISTRESS
651
6224.0
6224.0
6A LTD Coast/Intership
652
6227.0
6227.0
6B LTD Coast/Intership
653
6230.0
6230.0
6C LTD Coast/Intership
654
6516.0
6616.0
6D LTD Coast
WLO, Mobile, AL
DAYTIME ONLY
655
6209.0
6209.0
Mississippi River
656
6212.0
6212.0
Mississippi River
657
6510.0
6510.0
Mississippi River
658
6513.0
6513.0
Mississippi River
3.2.4
8 MHZ VOICE BAND
VOICE
SHIP
SHIP
RECEIVE
TRANSMIT
801
8719.0
8195.0
802
8722.0
8198.0
803
8725.0
8201.0
804
8728.0
8204.0
KMI, Point Reyes, CA
805
8731.0
8207.0
WOM, Ft. Lauderdale, FL
806
8734.0
8210.0
807
8737.0
8213.0
808
8740.0
8216.0
WOO, Manahawkin, NJ
809
8743.0
8219.0
KMI, Point Reyes, CA
810
8746.0
8222.0
WOM, Ft. Lauderdale, FL
811
8749.0
8225.0
WOO, Manahawkin, NJ
CHANNEL
ta8man.doc
Page 3-8
USE
WOM, Ft. Lauderdale, FL
FCCID: BZ6SEA245
812
8752.0
8228.0
813
8755.0
8231.0
814
8758.0
8234.0
WOM, Ft. Lauderdale, FL
815
8761.0
8237.0
WOO, Manahawkin, NJ
816
8764.0
8240.0
817
8767.0
8243.0
818
8770.0
8246.0
819
8773.0
8249.0
820
8776.0
8252.0
821
8779.0
8255.0
822
8782.0
8258.0
823
8785.0
8261.0
824
8788.0
8264.0
WLO, Mobile, AL
825
8791.0
8267.0
WOM, Ft. Lauderdale, FL
826
8794.0
8270.0
WOO, Manahawkin, NJ
KMI, Point Reyes, CA
WLC, Rogers City, MI
827
8797.0
8273.0
828
8800.0
8276.0
829
8803.0
8279.0
830
8806.0
8282.0
WLO, Mobile, AL
831
8809.0
8285.0
WOM, Ft. Lauderdale, FL
832
8812.0
8288.0
833
8291.0
8291.0
836
8713.0
8113.0
WLO, Mobile, AL
837
8716.0
8128.0
KGN, Delcambre, LA
850
8291.0
8291.0
DISTRESS
851
8294.0
8294.0
8A LTD Coast/Intership
852
8297.0
8297.0
8B LTD Coast/Intership
853
8201.0
8201.0
WFN, Jeffersonville,
Mississippi. River
ta8man.doc
Page 3-9
FCCID: BZ6SEA245
854
8213.0
8213.0
WGK, St. Louis, Miss. River
855
8725.0
8725.0
Mississippi River
856
8737.0
8737.0
Mississippi River
3.2.5
12 MHZ VOICE BAND
VOICE
SHIP
SHIP
RECEIVE
TRANSMIT
1201
13077.0
12230.0
KMI, Point Reyes, CA
1202
13080.0
12233.0
KMI, Point Reyes, CA
1203
13083.0
12236.0
KMI, Point Reyes, CA
1204
13086.0
12239.0
1205
13089.0
12242.0
1206
13092.0
12245.0
1207
13095.0
12248.0
1208
13098.0
12251.0
WOM, Ft. Lauderdale, FL
1209
13101.0
12254.0
WOM, Ft. Lauderdale, FL
1210
13104.0
12257.0
WOO, Manahawkin, NJ
1211
13107.0
12260.0
WOO, Manahawkin, NJ
1212
13110.0
12263.0
WLO, Mobile, AL
1213
13113.0
12266.0
1214
13116.0
12269.0
USCG, Miami/Portsmouth
1215
13119.0
12272.0
WOM, Ft. Lauderdale, FL
1216
13122.0
12275.0
1217
13125.0
12278.0
1218
13128.0
12281.0
1219
13131.0
12284.0
1220
13134.0
12287.0
1221
13137.0
12290.0
1222
13140.0
12293.0
1223
13143.0
12296.0
CHANNEL
ta8man.doc
Page 3-10
USE
WOM, Ft. Lauderdale, FL
WOM, Ft. Lauderdale, FL
FCCID: BZ6SEA245
1224
13146.0
12299.0
1225
13149.0
12302.0
1226
13152.0
12305.0
1227
13155.0
12308.0
1228
13158.0
12311.0
WOO, Manahawkin, NJ
1229
13161.0
12314.0
KMI, Point Reyes, CA
1230
13164.0
12317.0
WOM, Ft. Lauderdale, FL
1231
13167.0
12320.0
1232
13170.0
12323.0
1233
13173.0
12326.0
1234
13176.0
12329.0
1235
13179.0
12332.0
1236
13182.0
12335.0
1234
13176.0
12329.0
1235
13179.0
12332.0
WLO, Mobile, AL
1236
13182.0
12335.0
KGN, Delcambre, LA
1237
13185.0
12338.0
1238
13188.0
12341.0
1239
13191.0
12344.0
1240
13194.0
12347.0
1241
13197.0
12350.0
1250
12290.0
12290.0
DISTRESS
1251
12353.0
12353.0
12A LTD Coast/Intership
1252
12356.0
12356.0
12B LTD Coast/Intership
1253
12359.0
12359.0
12C LTD Coast/Intership
1254
12362.0
12362.0
PUB. COAST & Miss. River
1255
12365.0
12365.0
PUB. COAST & Miss. River
ta8man.doc
Page 3-11
WLO, Mobile, AL
WLO, Mobile, AL
FCCID: BZ6SEA245
3.2.6
16 MHZ VOICE BAND
VOICE
SHIP
SHIP
RECEIVE
TRANSMIT
1601
17242.0
16360.0
WOM, Ft. Lauderdale, FL
1602
17245.0
16363.0
KMI, Point Reyes, CA
1603
17248.0
16366.0
KMI, Point Reyes, CA
1604
17251.0
16369.0
1605
17254.0
16372.0
1606
17257.0
16375.0
1607
17260.0
16378.0
1608
17263.0
16381.0
1609
17266.0
16384.0
WOM, Ft. Lauderdale, FL
1610
17269.0
16387.0
WOM, Ft. Lauderdale, FL
1611
17272.0
16390.0
WOM, Ft. Lauderdale, FL
1612
17275.0
16393.0
1613
17278.0
16396.0
1614
17281.0
16399.0
1615
17284.0
16402.0
1616
17287.0
16405.0
1617
17290.0
16408.0
1618
17293.0
16411.0
1619
17296.0
16414.0
1620
17299.0
16417.0
1621
17302.0
16420.0
1622
17305.0
16423.0
1623
17308.0
16426.0
1624
17311.0
16429.0
KMI, Point Reyes, CA
1625
17314.0
16432.0
USCG, Miami, Portsmouth
1626
17317.0
16435.0
WOO, Manahawkin, NJ
1627
17320.0
16438.0
1628
17323.0
16441.0
CHANNEL
ta8man.doc
Page 3-12
USE
WOO, Manahawkin, NJ
WOM, Ft. Lauderdale, FL
WOO, Manahawkin, NJ
FCCID: BZ6SEA245
1629
17326.0
16444.0
1630
17329.0
16447.0
1631
17332.0
16450.0
1632
17335.0
16453.0
1633
17338.0
16456.0
1634
17341.0
16459.0
1635
17344.0
16462.0
1636
17347.0
16465.0
1637
17350.0
16468.0
1638
17353.0
16471.0
1639
17356.0
16474.0
1640
17359.0
16477.0
1641
17362.0
16480.0
1642
17365.0
16483.0
1643
17368.0
16486.0
1644
17371.0
16489.0
1645
17374.0
16492.0
1646
17377.0
16495.0
1647
17380.0
16498.0
1648
17383.0
16501.0
1649
17386.0
16504.0
1650
16420.0
16420.0
DISTRESS
1651
16528.0
16528.0
16A LTD Coast/Intership
1652
16531.0
16531.0
16B LTD Coast/Intership
1653
16534.0
16534.0
16C LTD Coast/Intership
1654
16537.0
16537.0
1655
16540.0
16540.0
1656
16543.0
16543.0
PUB. COAST & Miss. River
1657
16546.0
16546.0
PUB. COAST & Miss. River
ta8man.doc
Page 3-13
WOO, Manahawkin NJ
WLO, Mobile, AL
WLO, Mobile, AL
KGN, Delcambre, LA
WLO, Mobile, AL
FCCID: BZ6SEA245
3.2.7
18 MHZ VOICE BAND
VOICE
SHIP
SHIP
RECEIVE
TRANSMIT
1801
19755.0
18780.0
1802
19758.0
18783.0
1803
19761.0
18786.0
1804
19764.0
18789.0
1805
19767.0
18792.0
1806
19770.0
18795.0
1807
19773.0
18798.0
1808
19776.0
18801.0
1809
19779.0
18804.0
1810
19782.0
18807.0
1811
19785.0
18810.0
1812
19788.0
18813.0
1813
19791.0
18816.0
1814
19794.0
18819.0
1815
19797.0
18822.0
1851
18840.0
18840.0
18A LTD Coast/Intership
1852
18843.0
18843.0
18B LTD Coast/Intership
1853
18825.0
18825.0
1854
18828.0
18828.0
1855
18831.0
18831.0
1856
18834.0
18834.0
1857
18837.0
18837.0
CHANNEL
3.2.8
USE
WLO, Mobile, AL
22 MHZ VOICE BAND
VOICE
CHANNEL
ta8man.doc
SHIP
SHIP
RECEIVE
TRANSMIT
Page 3-14
USE
FCCID: BZ6SEA245
2201
22896.0
22000.0
2202
22699.0
22003.0
2203
22702.0
22006.0
2204
22705.0
22009.0
2205
22708.0
22012.0
2206
22711.0
22015.0
2207
22714.0
22018.0
2208
22717.0
22021.0
2209
22720.0
22024.0
2210
22723.0
22027.0
2211
22726.0
22030.0
2212
22729.0
22033.0
2213
22732.0
22036.0
2214
22735.0
22039.0
KMI, Point Reyes, CA
2215
22738.0
22042.0
WOM, Ft. Lauderdale, FL
2216
22741.0
22045.0
WOM, Ft. Lauderdale, FL
2217
22744.0
22048.0
2218
22747.0
22051.0
2219
22750.0
22054.0
2220
22753.0
22057.0
2221
22756.0
22060.0
2222
22759.0
22063.0
WOM, Ft. Lauderdale, FL
2223
22762.0
22066.0
KMI, Point Reyes, CA
2224
22765.0
22069.0
2225
22768.0
22072.0
2226
22771.0
22075.0
2227
22774.0
22078.0
2228
22777.0
22081.0
2229
22780.0
22084.0
2230
22783.0
22087.0
2231
22786.0
22090.0
ta8man.doc
Page 3-15
WOO, Manahawkin, NJ
WOO, Manahawkin, NJ
WOO, Manahawkin, NJ
KMI, Point Reyes, CA
FCCID: BZ6SEA245
2232
22789.0
22093.0
2233
22792.0
22096.0
2234
22795.0
22099.0
2235
22798.0
22102.0
2236
22801.0
22105.0
KMI, Point Reyes, CA
WOO, Manahawkin, NJ
2237
22804.0
22108.0
2238
22807.0
22111.0
2239
22810.0
22114.0
2240
22813.0
22117.0
2241
22816.0
22120.0
2242
22819.0
22123.0
2243
22822.0
22126.0
2244
22825.0
22129.0
2245
22828.0
22132.0
2246
22831.0
22135.0
2247
22834.0
22138.0
2248
22837.0
22141.0
2249
22840.0
22144.0
2250
22843.0
22147.0
2251
22159.0
22159.0
22A LTD Coast/Intership
2252
22162.0
22162.0
22B LTD Coast/Intership
2253
22165.0
22165.0
22C LTD Coast/Intership
2254
22168.0
22168.0
22D LTD Coast/Intership
2255
22171.0
22171.0
22E LTD Coast/Intership
2256
22174.0
22174.0
Public Coast
2257
22177.0
22177.0
Public Coast
ta8man.doc
Page 3-16
WLO, Mobile, AL
WLO, Mobile, AL
WLO, Mobile, AL
FCCID: BZ6SEA245
3.2.9
25 MHZ VOICE BAND
VOICE
SHIP
SHIP
RECEIVE
TRANSMIT
2501
26145.0
25070.0
2502
26148.0
25073.0
2503
26151.0
25076.0
2504
26154.0
25079.0
2505
26157.0
25082.0
2506
26160.0
25085.0
2507
26163.0
25088.0
2508
26166.0
25091.0
2509
26169.0
25094.0
2510
26172.0
25097.0
2551
25115.0
25115.0
25A LTD Coast/Intership
2552
25118.0
25118.0
25B LTD Coast/Intership
2553
25100.0
25100.0
2554
25103.0
25103.0
2555
25106.0
25106.0
2556
25109.0
25109.0
2557
25112.0
25112.0
CHANNEL
USE
WLO, Mobile, AL
3.2.10 DSC FREQUENCIES
DSC
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
2174.5
2174.5
NBDP EMER CALLING
201
2187.5
2187.5
DSC EMER CALLING
202
2177.0
2189.5
INTL DSC CALLING
203
2177.0
2177.0
INTERSHIP DSC CALLING
401
4207.5
4207.5
DSC EMER CALLING
402
4219.5
4208.0
INTL DSC CALLING
ta8man.doc
Page 3-17
USE
FCCID: BZ6SEA245
403
4220.0
4208.5
ATLANTIC DSC CALLING
404
4220.5
4209.0
PACIFIC DSC CALLING
601
6312.0
6312.0
DSC EMER CALLING
602
6331.0
6312.5
INTL DSC CALLING
603
6331.5
6313.0
ATLANTIC DSC CALLING
604
6332.0
6313.5
PACIFIC DSC CALLING
801
8414.5
8414.5
DSC EMER CALLING
802
8436.5
8415.0
INTL DSC CALLING
803
8437.0
8415.5
ATLANTIC DSC CALLING
804
8437.5
8416.0
PACIFIC DSC CALLING
1201
12577.0
12577.0
DSC EMER CALLING
1202
12657.0
12577.5
INTL DSC CALLING
1203
12657.5
12578.0
ATLANTIC DSC CALLING
1204
12658.0
12578.5
PACIFIC DSC CALLING
1601
16804.5
16804.5
DSC EMER CALLING
1602
16903.0
16805.0
INTL DSC CALLING
1603
16903.5
16805.5
ATLANTIC DSC CALLING
1604
16904.0
16806.0
PACIFIC DSC CALLING
1802
19703.5
18898.5
INTL DSC CALLING
1803
19704.0
18899.0
ATLANTIC DSC CALLING
1804
19704.5
18899.5
PACIFIC DSC CALLING
2202
22444.0
22374.5
INTL DSC CALLING
2203
22444.5
22375.0
ATLANTIC DSC CALLING
2204
22445.0
22375.5
PACIFIC DSC CALLING
2502
26121.0
25208.5
INTL DSC CALLING
2503
26121.5
25209.0
ATLANTIC DSC CALLING
2504
26122.0
25209.5
PACIFIC DSC CALLING
ta8man.doc
Page 3-18
FCCID: BZ6SEA245
3.2.11 4 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
401
4210.5
4172.5
WNU
402
4211.0
4173.0
ZLA
403
4211.5
4173.5
KFS
404
4212.0
4174.0
405
4212.5
4174.5
WLO
406
4213.0
4175.0
WLO, VIP
407
4213.5
4175.5
KBS
408
4214.0
4176.0
KLB, WPD
409
4214.5
4176.6
KLC
410
4215.0
4177.0
WLO
411
4177.5
4177.5
NBDP EMER CALLING
412
4215.5
4178.0
KBS
413
4216.0
4178.5
KPH
414
4216.5
4179.0
WCC
415
4217.0
4179.5
WLO
416
4217.5
4180.0
VCT
417
4218.0
4180.5
WLO
418
4218.5
4181.0
419
4219.0
4181.5
471
4202.5
4202.5
472
4203.0
4203.0
473
4203.5
4203.5
474
4204.0
4204.0
475
4204.5
4204.5
476
4205.0
4205.0
477
4205.5
4205.5
478
4206.0
4206.0
479
4206.5
4206.5
ta8man.doc
Page 3-19
USE
FCCID: BZ6SEA245
480
4207.0
4207.0
3.2.12 6 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
601
6314.5
6263.0
KFS
602
6315.0
6263.5
WNU
603
6315.5
6264.0
KFS
604
6316.0
6264.5
605
6316.5
6265.0
606
6317.0
62655
607
6317.5
6266.0
608
6318.0
6266.5
KLB
609
6318.5
6267.0
KLC
610
6319.0
6267.5
WLO
611
6268.0
6268.0
NBDP EMER CALLING
612
6319.5
6268.5
613
6320.0
6269.0
614
6320.5
6269.5
615
6521.0
6270.0
616
6321.5
6270.5
617
6322.0
6271.0
618
6322.5
6271.5
619
6323.0
6272.0
620
6323.5
6272.5
621
6324.0
6273.0
WCC
622
6324.5
62736
KPH, KLC
623
6325.0
6274.0
624
6325.5
6274.5
625
6326.0
6275.0
626
6326.5
6275.5
ta8man.doc
Page 3-20
USE
WLO
KPH
WLO
KLC
WLO
FCCID: BZ6SEA245
627
6327.0
6281.0
628
6327.5
6281.5
629
6328.0
6282.0
630
6328.5
6282.5
631
6329.0
6283.0
632
6329.5
6283.5
633
6330.0
6284.0
634
6330.5
6284.5
671
6300.5
6300.5
672
6301.0
6301.0
673
6301.5
6301.5
674
6302.0
6302.0
675
6302.5
6302.5
676
6303.0
6303.0
677
6303.5
6303.5
678
6304.0
6304.0
679
6304.5
6304.5
680
6305.0
6305.0
681
6305.5
6305.5
682
6306.0
6306.0
683
6306.5
6306.5
684
6307.0
6307.0
685
6307.5
6307.5
686
6308.0
6308.0
687
6308.5
6308.5
688
6309.0
6309.0
689
6309.5
6309.5
690
6310.0
6310.0
691
6310.5
6310.5
692
6311.0
6311.0
693
6311.5
6311.5
ta8man.doc
Page 3-21
FCCID: BZ6SEA245
3.2.13 8 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
801
8376.5
8376.5
NBDP EMER CALLING
802
8417.0
8377.0
WNU
803
8417.5
8377.5
KFS
804
8418.0
8378.0
805
8418.5
8378.5
WLO
806
8419.0
8379.0
WLO
807
8419.5
8379.5
808
8420.0
8380.0
809
8420.5
8380.5
KLC
810
8421.0
8381.0
WLO
811
8421.5
8381.5
WLO
812
8422.0
8382.0
813
8422.5
8382.5
814
8423.0
8383.0
815
8423.5
8383.5
WLO
816
8424.0
8384.0
WCC
817
8424.5
8384.5
KLC
818
8425.0
8385.0
KLB
819
8425.5
8385.5
820
8426.0
8386.0
821
8426.5
8386.5
WCC
822
8427.0
8387.0
KLC
823
8427.5
8387.5
824
8428.0
8388.0
825
8428.5
8388.5
826
8429.0
8389.0
827
8429.5
8389.5
ta8man.doc
Page 3-22
USE
KPH
WLO
FCCID: BZ6SEA245
828
8430.0
8390.0
829
8430.5
8390.5
830
8431.0
8391.0
831
8431.5
8391.5
832
8432.0
8392.0
833
8432.5
8392.5
834
8433.0
8393.0
835
8433.5
8393.5
836
8434.0
8394.0
837
8434.5
8394.5
838
8435.0
8395.0
839
8435.5
8395.5
840
8436.0
8396.0
871
8396.5
8396.5
872
8397.0
8397.0
873
8397.5
8397.5
874
8398.0
8398.0
875
8398.5
8398.5
876
8399.0
8399.0
877
8399.5
8399.5
878
8400.0
8400.0
879
8400.5
8400.5
880
8401.0
8401.0
881
8401.5
8401.5
882
8402.0
8402.0
883
8402.5
8402.5
884
8403.0
8403.0
885
8403.5
8403.5
886
8404.0
8404.0
887
8404.5
8404.5
888
8405.0
8405.0
ta8man.doc
Page 3-23
FCCID: BZ6SEA245
889
8405.5
8405.5
890
8406.0
8406.0
891
8406.5
8406.5
892
8407.0
8407.0
893
8407.5
8407.5
894
8408.0
8408.0
895
8408.5
8408.5
896
8409.0
8409.0
897
8409.5
8409.5
898
8410.0
8410.0
899
8410.5
8410.5
900
8411.0
8411.0
901
8411.5
8411.5
902
8412.0
8412.0
903
8412.5
8412.5
904
8413.0
8413.0
905
8413.5
8413.5
906
8414.0
8414.0
3.2.14 12 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
1201
12579.5
12477.0
1202
12580.0
12477.5
ZLA
1203
12580.5
12478.0
KFS
1204
12581.0
12478.5
1205
12581.5
12479.0
WLO
1206
12582.0
12479.5
VIP
1207
12582.5
12480.0
1208
12583.0
12480.5
1209
12583.5
12481.0
ta8man.doc
Page 3-24
USE
KLC
FCCID: BZ6SEA245
1210
12584.0
12481.5
VIP
1211
12584.5
12482.0
WLO
1212
12585.0
12482.5
1213
12585.5
12483.0
1214
12586.0
12483.5
1215
12586.5
12484.0
1216
12587.0
12484.5
1217
12587.5
12485.0
1218
12588.0
12485.5
1219
12588.5
12486.0
1220
12589.0
12486.5
1221
12589.5
12487.0
WCC
1222
12590.0
12487.5
KLC
1223
12590.5
12488.0
KLB
1224
12591.0
12488.5
1225
12591.5
12489.0
1226
12592.0
12489.5
1227
12592.5
12490.0
1228
12593.0
12490.5
1229
12593.5
12491.0
1230
12594.0
12491.5
1231
12594.5
12492.0
1232
12595.0
12492.5
1233
12595.5
12493.0
1234
12596.0
12493.5
1235
12596.5
12494.0
1236
12597.0
12494.5
1237
12597.5
12495.0
1238
12598.0
12495.5
1239
12598.5
12496.0
1240
12599.0
12496.5
ta8man.doc
Page 3-25
KPH
WLO
KLC
WNU
WLO
WLO
WLO
WCC
WLO
FCCID: BZ6SEA245
1241
12599.5
12497.0
1242
12600.0
12497.5
1243
12600.5
12498.0
1244
12601.0
12498.5
1245
12601.5
12499.0
1246
12602.0
12499.5
1247
12602.5
12500.0
1248
12603.0
12500.5
1249
12603.5
12501.0
1250
12604.0
12501.5
WLO
1251
12604.5
12502.0
WLO
1252
12605.0
12502.5
1253
12605.5
12503.0
1254
12606.0
12503.5
1255
12606.5
12504.0
1256
12807.0
12504.5
1257
12607.5
12505.0
1258
12608.0
12505.5
1259
12608.5
12506.0
1260
12609.0
12506.5
1261
12609.5
12507.0
1262
12610.0
12507.5
1263
12610.5
12508.0
1264
12611.0
12508.5
1265
12611.5
12509.0
1266
12612.0
12509.5
1267
12612.5
12510.0
1268
12613.0
12510.5
1269
12613.5
12511.0
1270
12614.0
12511.5
1271
12614.5
12512.0
ta8man.doc
Page 3-26
KPH
KLC
WLO
WNU
VCT
KEJ
FCCID: BZ6SEA245
1272
12615.0
12512.5
1273
12615.5
12513.0
1274
12616.0
12513.5
1275
12616.5
12514.0
1276
12617.0
12514.5
1277
12617.5
12515.0
1278
12618.0
12515.5
1279
12618.5
12516.0
1280
12619.0
12516.5
1281
12619.5
12517.0
1282
12620.0
12517.5
1283
12620.5
12518.0
1284
12621.0
12518.5
1285
12621.5
12519.0
1286
12622.0
12519.5
1287
12520.0
12520.0
1288
12622.5
12520.5
1289
12623.0
12521.0
1290
12623.5
12521.5
1291
12624.0
12522.0
1292
12624.5
12522.5
1293
12625.0
12523.0
1294
12625.5
12523.5
1295
12626.0
12524.0
1296
12626.5
12524.5
1297
12627.0
12525.0
1298
12627.5
12525.5
1299
12628.0
12526.0
1300
12628.5
12526.5
1301
12629.0
12527.0
1302
12629.5
12527.5
ta8man.doc
Page 3-27
NBDP EMER CALLING
SAB
FCCID: BZ6SEA245
1303
12630.0
12528.0
1304
12630.5
12528.5
1305
12631.0
12529.0
1306
12631.5
12529.5
1307
12632.0
12530.0
1308
12632.5
12530.5
1309
12633.0
12531.0
1310
12633.5
12531.5
1311
12634.0
12532.0
1312
12634.5
12532.5
1313
12635.0
12533.0
1314
12635.5
12533.5
1315
12636.0
12534.0
1316
12636.5
12534.5
1317
12637.0
12535.0
1318
12637.5
12535.5
1319
12638.0
12536.0
1320
12638.5
12536.5
1321
12639.0
12537.0
1322
12639.5
12537.5
1323
12640.0
12538.0
1324
12640.5
12538.5
1325
12641.0
12539.0
1326
12641.5
12539.5
1327
12642.0
12540.0
1328
12642.5
12540.5
1329
12643.0
12541.0
1330
12643.5
12541.5
1331
12644.0
12542.0
1332
12644.5
12542.5
1333
12645.0
12543.0
ta8man.doc
Page 3-28
FCCID: BZ6SEA245
1334
12645.5
12543.5
1335
12646.0
12544.0
1336
12646.5
12544.5
1337
12647.0
12545.0
1338
12647.5
12545.5
1339
12648.0
12546.0
1340
12648.5
12546.5
1341
12649.0
12547.0
1342
12649.5
12547.5
1343
12650.0
12548.0
1344
12650.5
12548.5
1345
12651.0
12549.0
1346
12651.5
12549.5
1347
12652.0
12555.0
1348
12652.5
12555.5
1349
12653.0
12556.0
1350
12653.5
12556.5
1351
12654.0
12557.0
1352
12654.5
12557.5
1353
12655.0
12558.0
1354
12655.5
12558.5
1355
12656.0
12559.0
1356
12656.5
12559.5
1371
12560.0
12560.0
1372
12560.5
12560.5
1373
12561.0
12561.0
1374
12561.5
12561.5
1375
12562.0
12562.0
1376
12562.5
12562.5
1377
12563.0
12563.0
1378
12563.5
12563.5
ta8man.doc
Page 3-29
FCCID: BZ6SEA245
1379
12564.0
12564.0
1380
12564.5
12564.5
1381
12565.0
12565.0
1382
12565.5
12565.5
1383
12566.0
12566.0
1384
12566.5
12566.5
1385
12567.0
12567.0
1386
12567.5
12567.5
1387
12568.0
12568.0
1388
12568.5
12568.5
1389
12569.0
12569.0
1390
12569.5
12569.5
1391
12570.0
12570.0
1392
12570.5
12570.5
1393
12571.0
12571.0
1394
12571.5
12571.5
1395
12572.0
12572.0
1396
12572.5
12572.5
1397
12573.0
12573.0
1398
12573.5
12573.5
1399
12574.0
12574.0
1400
12574.5
12574.5
1401
12575.0
12575.0
1402
12575.5
12575.5
1403
12576.0
12576.0
1404
12576.5
12576.5
3.2.15 16 MHZ TELEX BAND
TELEX
CHANNEL
1601
ta8man.doc
SHIP
RECEIVE
SHIP
TRANSMIT
16807.0
16683.5
Page 3-30
USE
FCCID: BZ6SEA245
1602
16807.5
16684.0
ZLA
1603
16808.0
16684.5
KFS
1604
16808.5
16685.0
KLB
1605
16809.0
16685.5
WLO
1606
16809.5
16686.0
VIP
1607
16810.0
16686.5
1608
16810.5
16687.0
1609
16811.0
16687.5
KLC
1610
16811.5
16688.0
VIP
1611
16812.0
16688.5
WLO
1612
16812.5
16689.0
1613
16813.0
16689.5
1614
16813.5
16690.0
1615
18814.0
16690.5
1616
16814.5
16691.0
1617
16815.0
16691.5
1618
16815.5
16692.0
1619
16816.0
16692.5
1620
16816.5
16693.0
1621
16817.0
16693.5
1622
16817.5
16694.0
1623
16818.0
16694.5
1624
16695.0
16695.0
NBDP EMER CALLING
1625
16818.5
16695.5
WLO
1626
16819.0
16696.0
1627
16819.5
16696.5
1628
16820.0
16697.0
1629
16820.5
16697.5
1630
16821.0
16698.0
1631
16821.5
16698.5
1632
16822.0
16699.0
ta8man.doc
Page 3-31
KPH
WLO
KLC
WNU
KPH, KLC
WLO
FCCID: BZ6SEA245
1633
16822.5
16699.5
1634
16823.0
16700.0
1635
16823.5
16700.5
1636
16824.0
16701.0
1637
16824.5
16701.5
1638
16825.0
16702.0
1639
16825.5
16702.5
1640
16826.0
16703.0
1641
16826.5
16703.5
1642
16827.0
16704.0
1643
16827.5
16704.5
1644
16828.0
16705.0
1645
16828.5
16705.5
1646
16829.0
16706.0
1647
16829.5
16706.5
KFS
1648
16830.0
16707.0
KLC
1649
16830.5
16707.5
1650
16831.0
16708.0
1651
16831.5
16708.5
1652
16832.0
16709.0
1653
16832.5
16709.5
1654
16833.0
16710.0
1655
16833.5
16710.5
1656
16834.0
16711.0
1657
16834.5
16711.5
1658
16835.0
16712.0
1659
16835.5
16712.5
1660
16836.0
16713.0
1661
16836.5
16713.5
1662
16837.0
16714.0
1663
16837.5
16714.5
ta8man.doc
Page 3-32
WCC
WLO
WLO
WLO
WNU
WLO
WNU
FCCID: BZ6SEA245
1664
16838.0
16715.0
1665
16838.5
16715.5
1666
16839.0
16716.0
1667
16839.5
16716.5
1668
16840.0
16717.0
1669
16840.5
16717.5
1670
16841.0
16718.0
1671
16841.5
16718.5
1672
16842.0
16719.0
1673
16842.5
16719.5
1674
16843.0
16720.0
1675
16843.5
16720.5
1676
16844.0
16721.0
1677
16844.5
16721.5
1678
16845.0
16722.0
1679
16845.5
16722.5
1680
16846.0
16723.0
1681
16846.5
16723.5
1682
16847.0
16724.0
1683
16847.5
16724.5
1684
16848.0
16725.0
1685
16848.5
16725.5
1686
16849.0
16726.0
1687
16849.5
16726.5
1688
16850.0
16727.0
1689
16850.5
16727.5
1690
16851.0
16728.0
1691
16851.5
16728.5
1692
16852.0
16729.0
1693
16852.5
16729.5
1694
16853.0
16730.0
ta8man.doc
Page 3-33
KEJ
VCT
SAB
FCCID: BZ6SEA245
1695
16853.5
16730.5
1696
16854.0
16731.0
1697
16854.5
16731.5
1698
16855.0
16732.0
1699
16855.5
16732.5
1700
16856.0
16733.0
1701
16856.5
16733.5
1702
16857.0
16739.0
1703
16857.5
16739.5
1704
16858.0
16740.0
1705
16858.5
16740.5
1706
16859.0
16741.0
1707
16859.5
16741.5
1708
16860.0
16742.0
1709
16860.5
16742.5
1710
16861.0
16743.0
1711
16861.5
16743.5
1712
16862.0
16744.0
1713
16862.5
16744.5
1714
16863.0
16745.0
1715
16863.5
16745.5
1716
16864.0
16746.0
1717
16864.5
16746.5
1718
16865.0
16747.0
1719
16865.5
16747.5
1720
16866.0
16748.0
1721
16866.5
16748.5
1722
16867.0
16749.0
1723
16867.5
16749.5
1724
16868.0
16750.0
1725
18868.5
16750.5
ta8man.doc
Page 3-34
FCCID: BZ6SEA245
1726
16869.0
16751.0
1727
16869.5
16751.5
1728
16870.0
16752.0
1729
16870.5
16752.5
1730
16871.0
16753.0
1731
16871.5
16753.5
1732
16872.0
16754.0
1733
16872.5
16754.5
1734
16873.0
16755.0
1735
16873.5
16755.5
1736
16874.0
16756.0
1737
16874.5
16756.5
1738
16875.0
16757.0
1739
18875.5
16757.5
1740
16876.0
16758.0
1741
16876.5
16758.5
1742
16877.0
16759.0
1743
16877.5
16759.5
1744
16878.0
16760.0
1745
16878.5
16760.5
1746
16879.0
16761.0
1747
16879.5
16761.5
1748
16880.0
16762.0
1749
16880.5
16762.5
1750
16881.0
16763.0
1751
16881.5
16763.5
1752
16882.0
16764.0
1753
16882.5
16764.5
1754
16883.0
16765.0
1755
16883.5
16765.5
1756
16884.0
16766.0
ta8man.doc
Page 3-35
FCCID: BZ6SEA245
1757
16884.5
16766.5
1758
16885.0
16767.0
1759
16885.5
16767.5
1760
16886.0
16768.0
1761
16886.5
16768.5
1762
16887.0
16769.0
1763
16887.5
16769.5
1764
16886.0
16770.0
1765
16888.5
16770.5
1766
16889.0
16771.0
1767
16889.5
16771.5
1768
16890.0
16772.0
1769
16890.5
16772.5
1770
16891.0
16773.0
1771
16891.5
16773.5
1772
16892.0
16774.0
1773
16892.5
16774.5
1774
16893.0
16775.0
1775
16893.5
16775.5
1776
16894.0
16776.0
1777
16894.5
16776.5
1778
16895.0
16777.0
1779
16895.5
16777.5
1780
16896.0
16778.0
1781
16896.5
16778.5
1782
16897.0
16779.0
1783
16897.5
16779.5
1784
16898.0
16780.0
1785
16898.5
16780.5
1786
16899.0
16781.0
1787
16899.5
16781.5
ta8man.doc
Page 3-36
FCCID: BZ6SEA245
1788
16900.0
16782.0
1789
16900.5
16782.5
1790
16901.0
16783.0
1791
16901.5
16783.5
1792
16902.0
16784.0
1793
16902.5
16784.5
1794
16796.5
16796.5
1795
16797.0
16797.0
1796
16797.5
16797.5
1797
16798.0
16798.0
1798
16798.5
16798.5
1799
16799.0
16799.0
1800
16799.5
16799.5
3.2.16 18 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
1801
19681.0
18870.5
1802
19681.5
18871.0
1803
19682.0
18871.5
1804
19682.5
18872.0
1805
19683.0
18872.5
1806
19683.5
18873.0
1807
19684.0
18873.5
1808
19684.5
18874.0
1809
19685.0
18874.5
1810
19685.5
18875.0
1811
19686.0
18875.5
1812
19686.5
18876.0
1813
19687.0
18876.5
1814
19687.5
18877.0
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1815
19688.0
18877.5
1816
19688.5
18878.0
1817
19689.0
18878.5
1818
19689.5
18879.0
1819
19690.0
18879.5
1820
19690.5
18880.0
1821
19691.0
18880.5
1822
19691.5
18881.0
1823
19692.0
18881.5
1824
19692.5
18882.0
1825
19693.0
18882.5
1826
19693.5
18883.0
1827
19694.0
18883.5
1828
19694.5
18884.0
1829
19695.0
18884.5
1830
19695.5
18885.0
1831
19696.0
18885.5
1832
19696.5
18886.0
1833
19697.0
18886.5
1834
19697.5
18887.0
1835
19698.0
18887.5
1836
19698.5
18888.0
1837
19699.0
18888.5
1838
19699.5
18889.0
1839
19700.0
18889.5
1840
19700.5
18890.0
1841
19701.0
18890.5
1842
19701.5
18891.0
1843
19702.0
18891.5
1844
19702.5
18892.0
1845
19703.0
18892.5
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FCCID: BZ6SEA245
1871
18893.0
18893.0
1872
18893.5
18893.5
1873
18894.0
18894.0
1874
18894.5
18894.5
1875
18895.0
18895.0
1876
18895.5
18895.5
1877
18896.0
18896.0
1878
18896.5
18896.5
1879
18897.0
18897.0
1880
18897.5
18897.5
1881
18898.0
18898.0
3.2.17 22 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
2201
22376.5
22284.5
2202
22377.0
22285.0
WNU
2203
22377.5
22285.5
KFS
2204
22378.0
22286.0
2205
22378.5
22286.5
2206
22379.0
22287.0
2207
22379.5
22287.5
2208
22380.0
22288.0
2209
22380.5
22288.5
KLC
2210
22381.0
22289.0
WLO
2211
22381.5
22289.5
2212
22382.0
22290.0
2213
22382.5
22290.5
2214
22383.0
22291.0
2215
22383.5
22291.5
2216
22384.0
22292.0
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KPH
WLO
FCCID: BZ6SEA245
2217
22384.5
22292.5
2218
22385.0
22293.0
2219
22385.5
22293.5
2220
22386.0
22294.0
2221
22386.5
22294.5
WCC
2222
22387.0
22295.0
KLC
2223
22387.5
22295.5
2224
22388.0
22296.0
2225
22388.5
22296.5
2226
22389.0
22297.0
2227
22389.5
22297.5
2228
22390.0
22298.0
2229
22390.5
22298.5
2230
22391.0
22299.0
2231
22391.5
22299.5
2232
22392.0
22300.0
2233
22392.5
22300.5
2234
22393.0
22301.0
2235
22393.5
22301.5
2236
22394.0
22302.0
2237
22394.5
22302.5
2238
22395.0
22303.0
2239
22395.5
22303.5
2240
22396.0
22304.0
2241
22396.5
22304.5
2242
22397.0
22305.0
2243
22397.5
22305.5
2244
22398.0
22306.0
2245
22398.5
22306.5
2246
22399.0
22307.0
2247
22399.5
22307.5
ta8man.doc
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KLC
WNU
KPH
KLB
FCCID: BZ6SEA245
2248
22400.0
22308.0
2249
22400.5
22308.5
2250
22401.0
22309.0
2251
22401.5
22309.5
2252
22402.0
22310.0
2253
22402.5
22310.5
2254
22403.0
22311.0
2255
22403.5
22311.5
2256
22404.0
22312.0
WLO
2257
22404.5
22312.5
WNU
2258
22405.0
22313.0
2259
22405.5
22313.5
2260
22406.0
22314.0
2261
22406.5
22314.5
2262
22407.0
22315.0
2263
22407.5
22315.5
2264
22408.0
22316.0
2265
22408.5
22316.5
2266
22409.0
22317.0
2267
22409.5
22317.5
2268
22410.0
22318.0
2269
22410.5
22318.5
2270
22411.0
22319.0
2271
22411.5
22319.5
2272
22412.0
22320.0
2273
22412.5
22320.5
2274
22413.0
22321.0
2275
22413.5
22321.5
2276
22414.0
22322.0
2277
22414.5
22322.5
2278
22415.0
22323.0
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KLC
WNU
WLO
WLO
WLO
FCCID: BZ6SEA245
2279
22415.5
22323.5
2280
22416.0
22324.0
2281
22416.5
22324.5
2282
22417.0
22325.0
2283
22417.5
22325.5
2284
22418.0
22326.0
2285
22418.5
22326.5
2286
22419.0
22327.0
2287
22419.5
22327.5
2288
22420.0
22328.0
2289
22420.5
22328.5
2290
22421.0
22329.0
2291
22421.5
22329.5
2292
22422.0
22330.0
2293
22422.5
22330.5
2294
22423.0
22331.0
2295
22423.5
22331.5
2296
22424.0
22332.0
2297
22424.5
22332.5
2298
22425.0
22333.0
2299
22425.5
22333.5
2300
22426.0
22334.0
2301
22426.5
22334.5
2302
22427.0
22335.0
2303
22427.5
22335.5
2304
22428.0
22336.0
2305
22428.5
22336.5
2306
22429.0
22337.0
2307
22429.5
22337.5
2308
22430.0
22338.0
2309
22430.5
22338.5
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FCCID: BZ6SEA245
2310
22431.0
22339.0
2311
22431.5
22339.5
2312
22432.0
22340.0
2313
22432.5
22340.5
2314
22433.0
22341.0
2315
22433.5
22341.5
2316
22434.0
22342.0
2317
22434.5
22342.5
2318
22435.0
22343.0
2319
22435.5
22343.5
2320
22436.0
22344.0
2321
22436.5
22344.5
2322
22437.0
22345.0
2323
22437.5
22345.5
2324
22438.0
22346.0
2325
22438.5
22346.5
2326
22439.0
22347.0
2327
22439.5
22347.5
2328
22440.0
22348.0
2329
22440.5
22348.5
2330
22441.0
22349.0
2331
22441.5
22349.5
2332
22442.0
22350.0
2333
22442.5
22350.5
2334
22443.0
22351.0
2335
22443.5
22351.5
2371
22352.0
22352.0
2372
22352.5
22352.5
2373
22353.0
22353.0
2374
22353.5
22353.5
2375
22354.0
22354.0
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FCCID: BZ6SEA245
2376
22354.5
22354.5
2377
22355.0
22355.0
2378
22355.5
22355.5
2379
22356.0
22356.0
2380
22356.5
22356.5
2381
22357.0
22357.0
2382
22357.5
22357.5
2383
22358.0
22358.0
2384
22358.5
22358.5
2385
22359.0
22359.0
2386
22359.5
22359.5
2387
22360.0
22360.0
2388
22360.5
22360.5
2389
22361.0
22361.0
2390
22361.5
22361.5
2391
22362.0
22362.0
2392
22362.5
22362.5
2393
22363.0
22363.0
2394
22363.5
22363.5
2395
22364.0
22364.0
2396
22364.5
22364.5
2397
22365.0
22365.0
2398
22365.5
22365.5
2399
22366.0
22366.0
2400
22366.5
22366.5
2401
22367.0
22367.0
2402
22367.5
22367.5
2403
22368.0
22368.0
2404
22368.5
22368.5
2405
22369.0
22369.0
2406
22369.5
22369.5
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FCCID: BZ6SEA245
2407
22370.0
22370.0
2408
22370.5
22370.5
2409
22371.0
22371.0
2410
22371.5
22371.5
2411
22372.0
22372.0
2412
22372.5
22372.5
2413
22373.0
22373.0
2414
22373.5
22373.5
3.2.18 25 MHZ TELEX BAND
TELEX
CHANNEL
SHIP
RECEIVE
SHIP
TRANSMIT
2501
26101.0
25173.0
2502
26101.5
25173.5
2503
26102.0
25174.0
2504
26102.5
25174.5
2505
26103.0
25175.0
2506
26103.5
25175.5
2507
26104.0
25176.0
2508
26104.5
25176.5
2509
26105.0
25177.0
2510
26105.5
25177.5
2511
26106.0
25178.0
2512
26106.5
25178.5
2513
26107.0
25179.0
2514
26107.5
25179.5
2515
26108.0
25180.0
2516
26108.5
25180.5
2517
26109.0
25181.0
2518
26109.5
25181.5
2519
26110.0
25182.0
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WLO
FCCID: BZ6SEA245
2520
26110.5
25182.5
2521
26111.0
25183.0
2522
26111.5
25183.5
2523
26112.0
25184.0
2524
26112.5
25184.5
2525
26113.0
25185.0
2528
26113.5
25185.5
2527
26114.0
25186.0
2528
26114.5
25186.5
2529
26115.0
25187.0
2530
26115.5
25187.5
2531
26116.0
25188.0
2532
26116.5
25188.5
2533
26117.0
25189.0
2534
26117.5
25189.5
2535
26118.0
25190.0
2536
26118.5
25190.5
2537
26119.0
25191.0
2538
26119.5
25191.5
2539
26120.0
25192.0
2540
26120.5
25192.5
2415
22374.0
22374.0
2571
25193.0
25193.0
2572
25193.5
25193.5
2573
25194.0
25194.0
2574
25194.5
25194.5
2575
25195.0
25195.0
2576
25195.5
25195.5
2577
25196.0
25196.0
2578
25196.5
25196.5
2579
25197.0
25197.0
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FCCID: BZ6SEA245
2580
25197.5
25197.5
2581
25198.0
25198.0
2582
25198.5
25198.5
2583
25199.0
25199.0
2584
25199.5
25199.5
2585
25200.0
25200.0
2586
25200.5
25200.5
2587
25201.0
25201.0
2588
25201.5
25201.5
2589
25202.0
25202.0
2590
25202.5
25202.5
2591
25203.0
25203.0
2592
25203.5
25203.5
2593
25204.0
25204.0
2594
25204.5
25204.5
2595
25205.0
25205.0
2596
25205.5
25205.5
2597
25206.0
25206.0
2598
25206.5
25206.5
2599
25207.0
25207.0
2600
25207.5
25207.5
2601
25208.0
25208.0
3.3
CAUTION! FREQUENCY TOLERANCE
Under FCC Rules, the frequency tolerance for the Marine Service is + 10 Hz. In
order to achieve this accuracy a frequency counter with long term accuracy of + 1
Hz should be used.
All work affecting the transmitter performance must be done by, or under the
supervision of, a person holding at least a General Radiotelephone FCC license.
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FCCID: BZ6SEA245
3.4
3.4.1
SETTING THE TRANSMITTER FREQUENCIES
THE MASTER CLOCK OSCILLATOR
1. Select the highest desired transmitter frequency (Such as 25083.0 kHz). With the
transmitter output connected to an appropriate dummy load and a few watts of reinserted carrier being generated, connect a high accuracy frequency counter (See
Paragraph 3.3) to the RF dummy load and adjust trimmer capacitor C56 on the
transceiver Main Board (ASY-0245-01) for the correct carrier frequency. The
trimmer capacitor is located next to the Master Clock crystal oven on the Main
Board Assembly.
3.4.2
ENABLING CARRIER REINSERTION
Using DIRECT FREQUENCY ENTRY mode (See PP 2.5.28 above), enter the
desired test frequency. E.g.: 25083.0 kHz. Select R3E from the MODE menu.
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FCCID: BZ6SEA245
4
4.1
INSTALLATION
MOUNTING THE TRANSCEIVER
The SEA 245 transceiver unit is compact enough to allow great flexibility in
location, even on smaller vessels. Several options for mounting are available. The
mounting bracket fits either over or under the transceiver for overhead or shelf
locations. Figure 4.1 shows the outline dimensions of the SEA 245 transceiver and
mounting bracket. The bracket can be used as a template to locate the mounting
holes. When choosing a location for the transceiver, take care to avoid areas
directly over a heater or lacking adequate ventilation.
Take special care not to block airflow over the cabinet, since this can cause
overheating and resultant damage to the transceiver.
4.2
A TYPICAL INSTALLATION
Figure 4.2 shows a typical installation consisting of five parts: 1. The SEA 245
Transceiver/DSC unit; 2. The SEA 1635 antenna coupler; 3. The SEA 2450
Remote Controller unit; 4. The system interconnection cables; 5. The antenna
system.
Any radio communications system operating in the MF/HF spectrum MUST have
an adequate ground connection, otherwise the overall efficiency of the radio
installation is degraded. In extreme cases, it may be impossible to properly load the
radiotelephone into the antenna.
The 50 ohm output impedance of the SEA 245 makes necessary to employ an
antenna system of the resonant or externally matched type. The use of the SEA
1635 antenna coupler in conjunction with a whip antenna allows an efficient
installation which will cover both the MF and HF bands. The SEA 1635 was
designed specifically for Marine applications, is easily interconnected with the
transceiver and compatible with most shipboard antenna installations. Note that the
SEA 245 is also compatible with the SEA 1612C and SEA 1631 antenna couplers.
These couplers are capable of superior performance with shorter antenna systems or
higher duty cycle applications.
On wooden or fiberglass boats, the use of a copper ground plane may be necessary.
On sailboats, the keel may perform adequately as a ground system. In any case, the
ground system MUST be joined to the antenna coupler with a heavy copper strap.
4.3
4.3.1
THE TRANSCEIVER UNIT REAR PANEL CONNECTION AND FUSES
THE POWER CONNECTOR
A heavy duty power plug is used on the SEA 245 to assure minimum voltage drop
in the primary power circuit. See Figure 4.3 for proper assembly of the power plug.
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Page 4-1
FCCID: BZ6SEA245
4.3.2
THE RF CONNECTOR
One type UHF female connector is provided on the SEA 245 rear panel. The output
impedance of this transceiver is 50 ohms. The most common types of coaxial
cables used are RG-58C/U and RG-213/U. The correct mating plug is the PL-259
or Amphenol 83-1SP.
4.3.3
THE PARALLEL INTERFACE PLUG
A fourteen contact screw terminal type plug is provided on the SEA 245 rear panel.
This plug (P2) provides access to both receiver and transmitter audio circuitry and
transmitter PTT line, allowing installation of an extension microphone. Also
provided is the switched, fused primary power (+12VSW) line, an "all tuned" flag
line for the companion antenna coupler (TND) and a "demand tune" (DMD TUNE)
line which allows the operator to cause the antenna coupler to retune if desired.
TERMINAL FUNCTION
GND - (Pin 1) Provides access to the negative side (ground) of the +12 volt supply.
Common to the chassis. This terminal is usually used for the coaxial shield for the
2187.5 kHz antenna feedline.
2187.5 ANT - (Pin 2) Antenna input for the 2187.5 KHz monitor receiver.
Compatible with either resonant antennas or the SEA 7003 Active Antenna System.
CAUTION! If the internal jumper is configured to provide +12 volts to the SEA
7002G Active Antenna, this pin will be at +12 volts with reference to chassis
ground.
TXAF - (Pin 3) Input for an alternative transmitter audio source such as a
MODEM. Configured for unbalanced 600 ohm lines. Nominal input level for full
modulation, 1 volt peak-to-peak.
LLAF - (Pin 4) Low level receiver output (unsquelched). Configured for
unbalanced 600 ohm lines, nominal output level 1 volt peak-to-peak.
DMD TUNE - (Pin 5) This terminal provides the connection to operate the
"DEMAND TUNE" in the SEA 1635 and SEA 1612C Antenna Tuners.
TND - (Pin 6) This terminal facilitates the connection of an "ALL TUNED"
indicator line from the companion antenna tuner. Grounding this line will cause the
"TND" annunciator on the display to light.
12 VSW - (Pin 7) 12 volts, switched through the normal PWR switch function.
Normally used to power an external antenna tuner such as the SEA 1635 or SEA
1612C. DO NOT EXCEED 3 AMPS. The fuse for this circuit is the 5 amp fuse
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Page 4-2
FCCID: BZ6SEA245
located on the PA/Filter board, ASY-0245-02.
GND - (Pin 8) Provides access to the negative side (ground) of the +12 volt supply.
Common to the chassis. This terminal is usually used as the ground return for
system antenna tuners.
SPKR - (Pin 9) Internal speaker input. A jumper to the AF terminal is required to
operate the internal speaker.
AF - (Pin 10) Output of the audio power amplifier, AC coupled.
impedance required is 3.2 ohms or greater.
Speaker
HANDSET - (Pin 11) This output terminal provides a 600 ohm source of receiver
audio for a handset receiver.
MIC - (Pin 12) Remote microphone input terminal. Compatible with 600 ohm
dynamic microphones.
PTT - (Pin 13) Remote microphone push-to-talk terminal. Grounding this pin
places the radiotelephone in the TRANSMIT mode.
GND - (Pin 14) Provides access to the negative side (ground) of the +12 volt
supply. Common to the chassis. This terminal is normally used to connect the
shield braid for a remote microphone or handset.
NOTE:
DO NOT USE THESE TERMINALS FOR HIGH-CURRENT
APPLICATIONS!
4.3.4
THE SEABUSS INTERFACE CONNECTOR
One nine contact screw terminal type plug (P1) is provided on the SEA 245
transceiver rear panel. (SEE Figure 4.4 and the System Interconnection Diagram,
Figure 4.5) The SEABUSS connector provides for interconnection between the
(optional) SEA 2450 Remote Controller and the SEA 245 Transceiver/DSC.
Standard SEABUSS interconnect cable is used and up to 150 feet (50 meters) of
cable is permitted between the SEA 245 and the Remote Controller(s).
SEABUSS CABLE TERMINAL FUNCTIONS
Pins 1 and 9 - System common ground. Used for -12VDC power return and
termination of shield braids.
Pin 2 - 12VSW terminal. Switched +12 volts from transceiver to remote controller.
Pin 3 - PTT line for radiotelephone. Connecting this terminal to ground places the
radiotelephone in the TRANSMIT mode.
Pins 4 and 5 - Balanced data lines. Approximately RS485 format, differential logic.
Use a shielded, twisted pair.
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FCCID: BZ6SEA245
Pins 6 and 7 - Balanced, bidirectional audio lines. Nominal audio level is
approximately 1 volt peak-to-peak. Use a shielded, twisted pair.
NOTE: THE USE OF SEA CABLE PN# CAB-2350-XXX IS RECOMMENDED
FOR THE INTERCONNECTION BETWEEN THE SEA 245 TRANSCEIVER
AND THE SEA 2450 REMOTE CONTROLLER.
SEA CABLE PN# CAB-1635-XXX IS RECOMMENDED FOR USE BETWEEN
THE SEA 245 TRANSCEIVER AND THE SEA 1635 ANTENNA TUNER. THIS
CABLE PROVIDES INTERCONNECTIONS FOR THE RF POWER, DC
POWER, GROUND, DEMAND TUNE AND TUNED FLAG LINES IN A
SINGLE CABLE. MAXIMUM RECOMMENDED CABLE LENGTH IS 150
FEET (45 METERS).
4.3.5
THE RS232 DB-9 INTERFACE CONNECTOR
One female DB-9 connector (P2) is provided on the SEA 245 transceiver rear panel.
(Figure 4.1 and the System Interconnect Diagram, Figure 4.4) This provides a
general purpose RS232 type serial interface connection to the SEA 245 operating
system.
RS232 CABLE TERMINAL FUNCTIONS
Pin 1 - No Connection.
Pin 2 - RXD Serial data RECEIVER pin for RS232 port.
Pin 3 - TXD Serial data TRANSMITTER pin for RS232 port.
Pin 4 - No Connection.
Pin 5 - RS232 port ground pin.
Pin 6 - DSR pin.
Pin 7 - NOT/RTS pin.
Pin 8 - NOT/CTS pin.
Pin 9 - No Connection.
4.4
FUSING
Three fuses are provided in the SEA 245, all mounted internally on the PA/Filter
board (ASY-0245-02). Fuse F1 is a 15 amp, automotive (autoblade) fuses (SEA PN
# FUS-0013-015). This fuse protects the +24 volt rail to the power output
transistors and is provided with a reverse polarity protection diode.
Fuse F2 is a 5 amp, automotive (autoblade) fuse (SEA PN# FRS-0013-005). This
fuse protects the +24 volt rail to the DC/DC power converter.
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Fuse F3 is a 5 amp, automotive (autoblade) fuse (SEA PN # FUS-0013-005). This
fuse protects the +12 volt output from the DC/DC power converter. This regulated
+12 volt rail is chassis ground referenced (Negative rail connected to chassis
ground) and powers the low level circuitry in the SEA 245 as well as external
accessories such as an external antenna tuner or the SEA 2450 Remote Controller.
4.5
THE GROUND CONNECTION
A stainless steel 10-32 bolt and nut are provided on the rear panel to facilitate a low
resistance connection between the radiotelephone chassis and the RF ground system.
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5
5.1
THEORY OF OPERATION
GENERAL
The SEA 245 is a double conversion MF/HF SSB transceiver of up conversion
design. The first intermediate frequency (IF) is 45 MHz and uses a relatively
narrowband (8 kHz) crystal topping filter in conjunction with front end low and high
pass filters to provide excellent image, spurious and harmonic rejection. This type
of broadband design results in a minimum of tuned circuits. The second
intermediate frequency of approximately 40 kHz permits the use of DSP
oversampling techniques to provide secondary selectivity.
Receiver baseband recovery uses IF based DSP circuitry.
The filtered,
downconverted 40 kHz IF signal is fed into the ADC and DSP circuitry provides
programmable receiver filtering and demodulation.
Transmitter baseband generation is likewise DSP based and uses the DSP/CODEC
circuitry and an I/Q modulator, together with an appropriate DSP algorithm to
generate the desired baseband signal at 45 MHz.
The frequency control circuitry in the SEA 245 uses a combination of two PLLbased frequency synthesizers and the system DSP engine to provide the various
frequency conversions.
The first conversion oscillator is the 90-150 MHz VCO, which uses a PLL-based
loop with a reference of 8 kHz. This oscillator is then divided by two to 45-75
MHz. The resulting coarse-tuned local oscillator has a resolution of 4 kHz, very fast
settling time and a low noise floor.
The second conversion VCO operates at 45.040 MHz. In the transmit mode, the
VCO operates at 45.016 MHz for the transmitter I/Q modulator circuitry. The loop
reference frequency is 8 kHz.
All frequency determining circuitry is locked to the master clock oscillator, a 12.288
MHz OCXO.
The SEA 245 operating system resides in the Front Panel/Controller Assembly. The
operator communicates with the operating system firmware through the 18 key
keypad. The Front Panel/Controller Assembly is actually a SEAbuss(c) Controller
designed to communicate with the Mainboard Controller through the standard
SEABUSS interface. The SEA 245 SEABUSS is designed to support a single SEA
2450 Remote Controller in addition to the Front Panel.
5.2
THE RECEIVER
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ta8man.doc
ANT
SEA 245
Receiver Block Diagram
Figure 5.2.1
Page 5-2
FCCID: BZ6SEA245
PA/FILTER BOARD
ASY-0245-02
LOW PASS
BAND SELECT
TX/RX
MAINBOARD
ASY-0245-01
RF GAIN
CTL
HI-PASS
Q2
LOW PASS
MIX-2
2nd LO
45.040 MHz
MIX-1
1st LO
45-75 MHz
FL-1
40 KHz
U5
45 MHz
U31 B/C
U3
U1
I.F.
U2
SQL
Q6
DSP
U7
VOLUME
CPU BOARD
ASY-0245-04
CODEC
U1
FRONT PANEL/CONTROLLER BOARD
ASY-0245-03
U10
A/D
U34
FL-2
U14
SPKR
5.2.1
BLOCK DIAGRAM
Figure 5.2.1 shows the block diagram of the receive mode. The received RF signal
is routed from the rear panel antenna jack to a low pass filter selected by a relay
bank on the PA/Filter Assembly (ASY-0245-02). The output of the filter is routed
from J4 on the PA/Filter Assembly through a coaxial cable to the receiver input
circuitry on the Mainboard Assembly (ASY-0245-01). The signal is further
bandpass filtered to reject interfering signals and input to the RF
preamplifier/attenuator, Q2. In the "on" state, the amplifier provides some 3-4 dB of
low-noise preamplifier gain. In the "off" state, the stage becomes an attenuator that
provides approximately 10 dB of signal attenuation. The use of this switched gain
stage improves the weak signal sensitivity of the receiver and provides a front-end
attenuator that is used to insure that large signals do not swamp the ADC in the DSP
engine. The preamplifier/attenuator stage output is routed to the first mixer and the
signal is upconverted to the first IF at 45 MHz.
The 45 MHz IF signal passes through a low noise MMIC gain stage to a 4-pole
crystal "topping" filter with approximately 8 kHz bandwidth, a second MMIC
amplifier stage and a second two-pole crystal filter into the second mixer. In the
second mixer the signal is combined with the second Local Oscillator frequency of
45040 kHz. The mixer output signal is buffered by low-noise amplifier U3,
converted to a push-pull signal by U5 and then applied to the input of the A/D
converter U34. U34 digitizes the signal and passes it to the DSP engine, which
provides all baseband filtering, fine-tuning, demodulation and AGC functions. The
audio signal is converted to balanced format for transmission over the SEABUSS
audio lines to the Front Panel/Controller board (ASY-0245-03). The Controller
provides squelch processing, volume control and a speaker amplifier.
5.2.2
RECEIVE RF CIRCUITRY AND FIRST MIXER
As previously discussed, an incoming signal is first passed through some shared
circuitry on the PA/Filter Board (ASY-0245-02). This consists of a bandswitched
array of low pass filters, a T/R relay and a PIN diode signal limiter which prevents
damage to receiver input circuitry in the presence of extremely large signals. The
received signal is then sent through a coaxial cable to the receiver input on the
Mainboard Assembly (ASY-0245-01). On the Mainboard, a high-pass filter
consisting of C1, L1 and C7 further filters the signal.
Diode CR1 is forward biased in the receive mode from the +12VRX rail and
reversed biased in the transmit mode from the +12VTX rail through CR2. This T/R
switching circuitry provides extra isolation between the low-level transmitter signal
and any signal leakage through the PA/Filter Board T/R switches. From CR1, the
received signal passes through a low-pass filter (C5, L2 and C6) to the
preamplifier/attenuator stage. This stage is a low noise, low gain (+4 dB) broadband
common-gate JFET amplifier.
A gain step is provided by switching the
preamplifier supply voltage on and off through Q6. When Q6 is OFF, the stage
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becomes an attenuator with a loss of approximately 10 dB. The output of the
preamplifier is then applied to double-balanced mixer MIX1. The use of a hot
carrier diode mixer assures minimal cross modulation and intermodulation
distortion in the receiver front end.
5.2.3
THE 45 MHz IF
The output from mixer MIX1 contains the desired signal upconverted to 45 MHz.
This signal is amplified by a low noise, high dynamic range MMIC amplifier that
establishes a good low noise 50-ohm termination for the mixer. Output of the first
IF amplifier is filtered by FIL1, a four-pole monolithic crystal filter of approximately
8 kHz bandwidth. This is the "topping" filter, which serves to remove the unwanted
secondary image, RF, and LO leakage as well as other unwanted upconverted HF
signals that fall outside the filter bandwidth. Following the topping filter is a second
MMIC amplifier stage and a second 2-pole filter. The total gain between the
receiver input and the 45 MHz output is approximately 12 dB. The maximum
allowable input signal with preamplifier on is approximately -3 dBm. Switching in
the attenuator raises this level to approximately +10 dBm.
5.2.4
THE SECOND MIXER/POST AMPLIFIER
The second mixer converts the 45 MHz IF signal down to the second IF frequency
of approximately 40 kHz. This mixer is a +13 dBm type, necessary to handle the
somewhat higher signal levels present at this point. Following the mixer, the signal
is passed through a low noise operational amplifier with a stage gain of 10 to a
phase splitter circuit with stage gain of unity. The phase splitter output drives the
differentially configured A/D input.
5.2.5
THE A/D CONVERTER
In IF/DSP receivers, system performance is highly dependent upon the
characteristics of the A/D converter that moves the signal from the analog to the
digital realm. In the SEA 245, A/D Converter U34 is a 24-bit, 96 kHz stereo ADC
with a dynamic range of 110 dB and greater than 100 dB signal-to-noise ratio. The
inputs to the ADC are full differential and the chip includes a reference filter and a
digital decimation filter, which minimizes requirements for anti-aliasing filtering.
The 40 kHz second IF signal from the main receiver and the 14.583 kHz second IF
signal from the 2187.5 kHz monitor receiver are each connected to one of the stereo
inputs of the ADC. The resulting digitized signals are then passed on to the system
DSP that is located on the CPU Board (ASY-0245-04).
5.2.6
THE CODEC
The CODEC is part of the CPU Board Assembly (ASY-0245-04) and uses AC'97
REV 1.03 architecture in a 18-bit sigma/delta configuration. The CODEC contains
both an A/D and a D/A converter. The A/D converter is used to convert transmitter
baseband signals into a digital bit stream suitable for processing in the DSP.
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The D/A converter works in both receive and transmit modes. While receiving,
digitally processed receiver signals from the DSP engine are converted back into the
analog realm for processing through the amplifier/loudspeaker system. When
transmitting, digitally processed (and generated) baseband signals from the DSP
engine become the analog input signals to I/Q modulator chip U6 on the Mainboard
Assembly.
5.2.7
THE DIGITAL SIGNAL PROCESSOR
The main DSP engine in the SEA 245 consists of U7 on the CPU Board Assembly.
This is a TMS320VC5402, a specialized type of microprocessor which includes
such features as a 40-bit ALU, data bus with Bus-Holder feature, extended
addressing mode for 1Mx16-bit maximum external program space and many other
specialized features intended to facilitate the specialized math functions necessary
for DSP.
In the SEA 245, the DSP circuitry and firmware perform most of the signal
processing functions necessary to convert a radio signal into an audio signal and
vice-versa. These functions include frequency conversion, filtering, demodulation
and gain control in the receive mode and baseband signal processing, filtering and
generation in the transmit mode.
Since the DSP engine is actually a highly specialized type of microprocessor many,
indeed most, of the characteristics of the receiver and transmitter functions are
controlled by firmware algorithms embedded in the CPU Board memory. It is thus
possible to use the same system digital hardware to generate (and demodulate) voice
signals, TELEX signals, Digital Selective Calling signals or essentially any signal
format up to the bandwidth limitations of the system analog hardware. Receiver
AGC characteristics, transmitter bandwidth shaping and ALC functions are all
determined in firmware.
5.2.8
THE RECEIVER AGC SYSTEM
There is only one variable gain element in the receiver AGC system, JFET
preamplifier Q2. The amplifier passes signals whether or not it is enabled but, when
disabled, there is approximately 10 dB of attenuation with respect to the enabled
state. The actual AGC parameters are determined by the DSP algorithm and are
tailored to suit the mode selected. When receiving SSB signals, the AGC has the
usual fast attack-slow release characteristics suitable for SSB. The DSP software
monitors signal level and disables the preamplifier when necessary to protect the
A/D input from overload.
5.2.9
THE RECEIVER AUDIO CIRCUITY
The received signal is processed through the DSP engine and converted to an audio
baseband signal in the system CODEC. This signal then exits the CPU Board as the
SPKR.AF signal on pin 19 of J3 on the Mainboard and then passes through audio
gate U30C to the audio SEABUSS driver stage consisting of U31B and U31C.
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SEA 245
Transmitter Block Diagram
Figure 5.3.1
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MIC
CONTROLLER
ASY-0245-03
U10/DC
PA/FILTER
Q1
Q3
Q2
MAINBOARD
ASY-0245-01
U31A
Q7
Q6
2nd LO
45.016 MHz
90°
CODEC
U1
PA/FILTER
ASY-0245-02
TX/RX
Q5
DSP
U7
Q4
Q3
LOW
PASS
45MHz
FL1
BAND SELECT
MIX-1
1st LO
45-75 MHz
ANT
The audio signal then leaves the Mainboard Assembly (ASY-0245-01) as a 600
ohm balanced 0 dBm level and is received by the SEABUSS audio receiver in the
Front Panel/Controller Assembly consisting of balanced line amplifier U10A.
After passing through U10A, the signal is then sent to the VOLUME control and the
squelch limiter U8A and U8B. The signal from the VOLUME control wiper then
goes to AF Power Amplifier U14 where it is amplified to a 4-Watt level and is then
sent to the loudspeaker.
The limited audio signal from U8A is sent to an input of the Controller
microprocessor (U1) where it is used to generate the SQL signal. An algorithm in
U1 senses the presence (or absence) of a voice signal in the limited audio signal and,
when the Squelch function is activated, generates a SQL OUT signal. The SQL
OUT signal is used to turn on the squelch gate transistor Q6 to silence the
loudspeaker.
5.3
5.3.1
THE TRANSMITTER
BLOCK DIAGRAM
Figure 5.3.1 shows the block diagram of the SEA 245 in the transmit mode.
Microphone audio is amplified and converted to a balanced format for transmission
from the Front Panel/Controller Assembly to the Mainboard Assembly (ASY-024501) via the SEAbuss audio lines. On the -01 board it is converted back to
unbalanced format and then digitally sampled by CODEC U1 on the CPU board
(ASY-0245-04). The CODEC transfers the data serially to the DSP, U7. The DSP
generates a SSB signal at the (nominal) subcarrier frequency of 16 kHz. The
CODEC converts the digital sample stream back to analog format. The resulting I
and Q SSB signals are fed back to the Mainboard and into the inputs of quadrature
modulator U6. The modulator mixes the I and Q signals with in-phase and
quadrature 45.016 MHz local oscillator signals. This results in a single sideband
signal at the 45 MHz intermediate frequency. This IF signal is passed through the
bilateral 45 MHz crystal filter into the IF port of mixer MIX1. This mixer
downconverts the IF signal into the MF/HF RF band. The RF signal is low-pass
filtered and amplified before being passed on to the PA/Filter Assembly (ASY0245-02) via a coaxial cable. Transmitter preamplifier Q1 boosts the signal level
sufficiently to drive the push-pull driver stage consisting of Q2 and Q3. The driver
output is then routed to the push-pull power amplifiers, Q6 and Q7. The output of
the amplifier is then routed through the T/R relay to a low pass filter that is relay
selected for the desired band of operation. The filtered output is fed to the antenna
jack on the SEA 245 rear panel.
5.3.2
THE MICROPHONE AUDIO CIRCUITRY
The 600 ohm dynamic microphone output is terminated by 620 ohm resistor R8 and
then passes through R94 and C13X to the input of the amplifier/phase splitter stage
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consisting of operational amplifiers U10C and U10D. MOSFET Q5 is connected
between the junction of R94 and C13X and ground and serves to mute the
microphone circuitry in the receive mode. The balanced audio output from U10C
and U10D passes through analog gates U13A and U13D to the SEAbuss audio line.
The SEABUSS audio interconnection between the Front Panel/Controller
Assembly (ASY-0245-03) and the Mainboard Assembly (ASY-0245-01) is through
the 8-pin ribbon cable between P2 on the Controller board and J4 on the Mainboard.
These 8-pin DIP interconnections constitute an internal SEABUSS interface
between the two assemblies.
5.3.3
THE AUDIO LINE RECEIVER/TRANSMITTERS
SEABUSS audio is bidirectional and passes through audio line receiver/transmitters
at both ends of the path.
The receiver/transmitter circuitry consists of a balanced input line receiver and a
balanced output line driver or transmitter. The line driver is connected to the
SEAbuss(c) line through analog gates. These gates disconnect the line driver from
the SEABUSS when the receiver/transmitter is in the receive mode. In the receive
mode, balanced audio is presented to the input of an operational amplifier connected
as a differential amplifier. Balanced operation permits a high degree of common
mode rejection, insuring good noise rejection. The output of the line receiver is
unbalanced audio which is then passed on to the internal radiotelephone circuitry.
When the receiver/transmitter circuitry is in the transmit mode, the analog gates are
turned on, connecting the balanced output of the two amplifier line driver to the
SEABUSS.
SEABUSS audio level is nominally 2 volts peak-to-peak balanced (0 dBm).
5.3.4
THE CODEC AND DIGITAL SIGNAL PROCESSOR
CODEC, U1, digitizes audio from the microphone circuitry at a rate of 96
kilosamples each second. The samples are transferred to the DSP U7 for
processing. The DSP performs audio processing to maintain a relatively uniform
audio level and to reduce the peak-to-average ratio of the audio. This facilitates
more efficient use of the RF power amplifier. The audio is also bandpass filtered to
remove unwanted components, particularly above 2900 Hz. The audio is then
converted to a single sideband signal at the (nominal 16 kHz) subcarrier frequency.
This SSB signal is then passed through the CODEC and converted to I and Q analog
signals.
5.3.5
THE QUADRATURE MODULATOR
The I and Q signals from the CODEC are sent to quadrature modulator U6 on the
Mainboard. This modulator consists of a PLL based LO phase shifter, two mixers
and a combiner. A 45.016 MHz local oscillator (LO) signal from the synthesizer is
AC coupled into the modulator. The internal PLL circuit regenerates the 45.016
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MHz LO and produces two 45.016 MHz LO signals with a 90 degree phase
differential. These are used as the two local oscillators for the mixers. One is
mixed with the I component and the other is mixed with the Q component. The two
mixer outputs are summed to complete the single sideband mixer. In the summer
the desired sideband adds constructively while the undesired sideband cancels out,
producing a single sideband signal with a center frequency of 45 MHz. A DC bias
network with three trimpots (R77, R78, and R85) allows adjustment of opposite
(image) sideband and carrier suppression.
5.3.6
45 MHz IF AND SIGNAL MIXER
The 45 MHz signal from the quadrature modulator passes through switching
diode/attenuator CR6 to topping filter FIL1A/FIL1B. When in the transmit mode,
CR6 is biased on by the +12VTX rail through resistors R48 and R66. Bias current
is approximately 10 mA, resulting in a low loss switch. Monolithic filter
FIL1A/FIL1B is matched to the low impedances of the quadrature modulator and
mixer by the two "L" networks, L10/C39 and L9/C38. The filter output is passed
through CR5 to a attenuator consisting of R34, R35 and R36 and then through CR4
to the IF port of MIX1
5.3.7
THE LOW PASS FILTER AND TRANSMITTER PREAMPLIER
The downconverted transmitter signal from MIX1 is passed through a seven section
elliptical function low pass filter which provides some 50 dB of rejection for the
image and IF frequencies above 30 MHz. The filtered MF/HF signal is then passed
through diode switch CR3 to the input of the transmitter preamplifier. L6, A 27 μH
choke, serves as a simple high pass filter to restrict signal into the preamplifier to the
MF/HF spectrum. The transmitter preamplifier is a two-stage wide band amplifier.
The first stage consists of transistors Q3 and Q4 in a negative feedback voltage
amplifier. The output of this stage is taken from the low impedance emitter of Q4
and further amplified by Q5. Q5 is a transformer coupled power amplifier which is
used to boost the power output level of the SSB signal to the approximately 4 mW
(+6 dBm) required by the PA/Filter Assembly (ASY-0245-02). The signal exits the
Main Board via coaxial cable and enters the PA/Filter board on J1.
5.3.8
THE TRANSMITTER PREDRIVER
The low level transmitter signal is routed from J1 through a 3 dB pad and a
wideband transformer (T1) to the base of Q1. Q1 is a 2N3866 connected in the
common emitter configuration and is transformer coupled to the push-pull driver
stage. Bias for Q1 is provided by the base resistor network with R6 used to adjust
the idling (no signal) current in the device to 60 mA (0.275 volts across R7/R8).
The emitter resistor (R7/R8) is used together with press-on heat sink to provide
thermal stability for Q1.
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5.3.9
THE TRANSMITTER DRIVER
Transistors Q2 and Q3 are small plastic RF power devices connected as a push-pull
common emitter amplifier. Transformer T2 provides push-pull base drive from the
predriver, while transformers T3 and T4 provide DC power isolation and collector
to load impedance matching, respectively. Gain/bandwidth compensation is
provided by the collector/base feedback networks and the various peaking capacitors
and terminating resistors. Temperature tracking bias is provided for Q2 and Q3 by
the circuitry associated with Q4 and Q5. Q4 is a small silicon power transistor
connected as a voltage amplifier and buffered by power emitter follower Q5. The
current in Q4 is proportional to temperature. This causes the collector voltage to
drop as heat sink temperature rises. The collector voltage is the source of base drive
for the bias buffer emitter follower Q5. Bias current for Q2 and Q3 is adjusted to
140 mA by the potentiometer, R14, in the emitter circuit of Q4. Collector voltage
for Q4 is derived from the +10VTX bus, while collector voltage for Q5 is derived
from the +12VTX rail.
5.3.10 THE TRANSMITTER POWER AMPLIFIER
The power amplifier in the SEA 245 is a push-pull common emitter design with a
temperature stabilized bias source. The amplifier runs from the +24 volt input and
has the collector voltage present at all times. The amplifier is activated by turning
on the various bias supplies when in the transmit mode.
Since the +24 volt power source is isolated from the chassis, the power amplifier
bias generator must be powered from the +24 volt rail. The bias generator circuitry
consists of Q8, Q9 and regulator U4. +24 volt power for U4 and Q8 is switched by
the +12VTX rail through Q12 by optical isolator U5. When the +12VTX rail is
high U5 turns on Q12, energizing the bias generator circuitry. Q8 serves as a power
emitter follower to buffer the voltage generated by the temperature-tracking
amplifier, Q9. Q9 is a small power transistor that is thermally linked to the power
amplifier heat sink. To insure stability in the presence of varying line voltages, the
collector voltage for Q9 is obtained from 9 volt regulator U4. R28 permits
adjustment of the idling (no signal) current in Q6 and Q7 to 150 mA.
5.3.11 THE OUTPUT LOW PASS FILTERS
Five low pass filters are provided to cover the frequency range from 1.6 - 30 MHz.
Note that the highest frequency filter, which covers the-26 - 30 MHz spectrum, is a
3-pole elliptical function design, while the lower frequency filters are 7 pole
elliptical function types. This is possible because of the natural drop in spurious
outputs from the power amplifier at higher frequencies. Filter selection is through
small power relays, which are operated by the Mainboard controller computer
through a serially loaded relay driver consisting of shift register U2 and bufferdriver U3.
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5.3.12 THE ALC CIRCUITRY
The transmitter ALC circuitry is DSP based. The control signals for the ALC
system are derived from the dual directional coupler consisting of transformers T13
and T14 and termination resistors R44, R47 and R48. The forward power signal is
detected by CR3 and scaled by resistors R49 and R50 before being buffered by
U1B. The reflected power signal is detected by CR4 and buffered by U1A. The
buffered analog voltages corresponding to forward and reflected power levels are
then routed through the Mainboard to A/D converter inputs on the CPU board
microprocessor, U5.
5.4
5.4.1
THE MASTER CLOCK OSCILLATOR AND SYNTHESIZER SYSTEM
BLOCK DIAGRAM
Figure 5.4.1 shows the block diagram of the local oscillator system of the SEA 245.
The block diagram illustrates a total of two synthesizers. The first local oscillator
operates from 45 to 75 MHz and uses three bandswitched VCOs. These are
controlled by synthesizer chip, U21, which contains a dual modulus divide-by-N
counter, a variable modulus reference counter and a phase detector. The basic
reference rate for the phase detector is 8 kHz, which sets the "coarse" step size for
the first local oscillator to 4 kHz. (The VCO signal tunes from 90 to 150 MHz and
is divided by two before being applied to the first mixer.)
The second local oscillator synthesizer operates at 45.040 MHz with a reference rate
of 8 kHz.
5.4.2
THE MASTER CLOCK OSCILLATOR
Primary frequency control is maintained through a master temperature-stable crystal
oscillator (TCXO) operating at 12.288 MHz. Clock stability is achieved through a
combination of temperature control and temperature compensation. The Master
Clock Oscillator crystal Y2 is mounted in a proportional oven to insure stability.
Unbuffered HCMOS U9 and U25 gates are used for both oscillator and buffer
amplifier functions. Trimmer capacitor C56 is used to set the clock frequency.
5.4.3
THE FIRST LOCAL OSCILLATOR SYNTHESIZER
The first LO synthesizer consists of three switched VCOs, a buffer amplifier and a
phase locked loop circuit. The synthesizer generates local oscillator frequencies
from 45.4 - 75.0 MHz corresponding to operating frequencies of 0.4 - 30.0 MHz.
The oscillators themselves operate at twice the desired output frequency, however.
Operation of a typical VCO is described below. Q23 is configured as a Colpitts
oscillator with inductor L35 and varactor diode CR15 serving as the frequency
determining elements. Q24 buffers the VCO to prevent load pulling. These
components make up the highest frequency VCO, which tunes from approximately
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130 to 150 MHz.
Switch transistors Q16, Q17 and Q18 provide power to the selected VCO. The base
of Q18 is pulled low through R146 supplying 10 volts to the HIGHBAND VCO,
Q23-Q24. When the MIDBAND VCO is selected, Q13 will be turned on by a high
on pin 16 of U21. This will pull the base of Q17 low, energizing Q21 and Q22. At
the same time the base of Q18 is pulled high through diode CR10 switching OFF
the HIGHBAND VCO. Similarly, selection of the LOWBAND VCO is
accomplished by a high on pin 15 of U21, which turns on Q14/Q16, supplying
power to Q19/Q20 and
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SEA 245
Synthesizer Block Diagram
Figure 5.4.1
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UNLK
CS1
SYNDATA
SYNCLK
U17
12.288MHz
TO CPU
U22A/B
Q12
Q13
Q23,Q24
Q21,Q22
SYNDATA
SYNCLK
CS2
Q19,Q20
BAND
SWITCH
U21
12.288MHz
U18A
U18B
TRIM
CLK
U39A/B
C56
45.04/45.016MHz
OVE1
+12VS
U23
TX ENABLE
CR24
45.016MHz
Q33
U25
TO I/Q MODULATOR, U6
Y2
U9
90-150MHz
U24
45.04MHz
2nd LO
TO MIX-2
12.288MHz
MASTER CLK
45-75MHz
1st LO
TO MIX-1
holding OFF the HIGHBAND VCO through diode CR10. Steering diodes CR17
and CR18 are used to provide isolation between the two OFF VCOs and the active
output.
The output from the selected VCO is passed through prescaler, U23 where the
signal is divided by two. The prescaler output is buffered by MMIC, U24, before
being sent to the first mixer. The VCO output is also passed through dual buffer
amplifiers U39A and U39B. The output signal from U39B provides the VCO signal
to the synthesizer chip U21. Using separate amplifiers in this fashion improves the
isolation between the receiver mixer circuitry and the input to the synthesizer chip.
Serially loaded PLL chip U21 provides a reference counter, divide-by-N counter, a
phase/frequency detector and the VCO control register. The PLL reference
frequency is derived from the 12.288 MHz Master Clock. Loop filtering and level
shifting of the PLL phase detector output is accomplished by active filters U22A/B.
5.4.4
THE SECOND LOCAL OSCILLATOR SYNTHESIZER
The second local oscillator synthesizer consists of PLL chip U17, 45.040 MHz
Colpitts oscillator FET Q12, and buffer amplifier Q13, U18A, U18B and Q33.
Buffer amplifier U18A provides a sample of the 45.040 MHz VCO signal for the
synthesizer chip while U18B provides 45.040 MHz drive for the second mixer.
5.5
5.5.1
THE 2187.5 kHz MONITOR RECEIVER
BLOCK DIAGRAM
Figure 5.5.1 shows the block diagram of the 2187.5 kHz monitor receiver, required
for GMDSS applications is Sea Area 2. The receiver is a single channel, dual
conversion design which uses a single crystal to provide both conversion signals.
The first IF frequency is 455 kHz, the second IF frequency is nominally 14.583 kHz.
As in the SEA 245 Main Receiver, the DSP engine provides all channel selectivity,
signal demodulation, and AGC.
5.5.2
RECEIVER RF CIRCUITRY AND FIRST MIXER
Antenna input to the 2187.5 monitor receiver is on pins 13 (signal) and 14 (ground)
of the rear panel Accessory Connector. The impedance is 50 ohms and provisions
have been made to support the SEA 7002 Active Antenna, should this be desired.
The RF signal first passes through a high pass filter and a low pass filter to Q9, the
preamplifier. The preamplifier is a grounded-gate JFET with tuned drain circuit.
The nominal gain of this stage is about 8 dB with the drain voltage on. As in the
main receiver, switching the drain voltage off under control of the AGC software in
the DSP provides a gain step. The combination of the front end 5-section low pass
filter and the low pass response of the preamplifier drain circuitry combine to
provide the receiver with better than 75 dB rejection of the 3097.5 kHz primary
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image.
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FCCID: BZ6SEA245
ta8man.doc
SEA 7002 or
ANTENNA
2187.5KHz
SEA 245
2187.5 KHz MONITOR BLOCK DIAGRAM
Figure 5.5.1
Page 5-16
FCCID: BZ6SEA245
ANT.
7002
+12VRX
C116
ADJ
CLK
BANDPASS
FILTER
5285.0 KHz
Y1
U14
Q9
GAIN CONTROL
U13
U12A
MIX-3
2642.5 KHz
L20
U11
Q10
U10A
Q11
TO ADC @
14.583KHz
880.833 KHz
U12B
455KHz
FL-3
U7A/B
U10B
440.4167
KHz
U15
MIX-4
L26
C107
The first mixer is a conventional +7 dBm double balanced type, which provides
excellent dynamic range in this application.
5.5.3
THE 455 kHz IF AMPLIFIER
The first 455 kHz IF amplifier is Q10, a grounded-gate JFET which provides some
gain and serves as a wideband 50 ohm termination for the mixer. The output from
the amplifier is passed through FL3, a 6-pole ceramic bandpass filter with a nominal
bandwidth of 4 kHz. Output from the filter is then passed through emitter follower
Q11 to the second mixer.
5.5.4
THE SECOND MIXER/POST AMPLIFIER
The second mixer is a double balanced commutation mixer, which uses a quad
HCMOS analog gate (U16) as the switching element. Push-pull signal drive is
provided to the two switch arms through a wideband transformer. (Note that two
gate elements are used in each switch arm.) Push-pull local oscillator drive is
applied to the switch actuator pins from the output of the local oscillator divider
chain. Both output arms of the switch are summed together, resulting in a doublebalanced switching mixer with excellent dynamic range and good local oscillator
balance.
Output from the mixer is passed through a low pass filter consisting of L26 and
C107 to a low noise operational amplifier stage with gain of 10 and a phase splitter,
which, as in the Main Receiver, drives the A/D input.
5.5.5
THE LOCAL OSCILLATOR CIRCUITRY
Both conversion oscillator frequencies are derived from the same crystal controlled
source in the following fashion. Crystal oscillator U14 operates at 5285.0 kHz. This
oscillator is temperature compensated and maintains a frequency stability of less
than ±4 ppm over the voltage and temperature range of the equipment. Trimmer
capacitor C116 is used to set the oscillator frequency to exactly 5285.0 kHz at TP10.
Output from the oscillator is buffered by gate U13 and then divided to 2642.5 kHz
by U12A. This signal is sent to both the first mixer and the second local oscillator
divider chain. The difference frequency between the first local oscillator and the
2187.5 kHz signal frequency is 455 kHz.
U11, U12B and U10A form a symmetrical divide-by-three counter. The resulting
880.3333 kHz signal is then further divided by two in U10B. The Q and notQ
outputs of U10B are at 440.4167 kHz and, when mixed in MIX-4 with the 455 kHz
IF signal, results in the 14.5833 kHz last IF frequency which is amplified by U3 and
U5A/B and then sent through the A/D converter to the DSP for further filtering and
demodulation.
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FCCID: BZ6SEA245
5.6
5.6.1
THE POWER SUPPLY CIRCUIT
GENERAL
The basic supply voltage for the SEA 245 is a floating ground 24 Volt DC source.
Line voltage regulation of ±15% or better is required, with a current capacity of at
least 15-20 amperes. From this raw source are derived the necessary regulated
operating voltages for the SEA 245 circuitry.
5.6.2
BLOCK DIAGRAM
Figure 5.6.1 shows a simplified schematic diagram of the power supply circuitry.
Once the basic 24 Volt DC power is provided, it is connected to the set through the
heavy-duty power plug on the transceiver rear panel. A variety of internally
mounted fuses are provided to protect the set in the event of malfunction. The
primary line fuses are equipped with a polarity protection diode that will blow the
line fuses in the event of reversed line polarity.
As illustrated in Figure 5.6.1, the 24 Volt DC power from the rear panel mounted
connector passes through a ferrite line filter to the PA/Filter Board (ASY-0245-02)
where the power is distributed to the internal circuitry through fuses F1 and F2.
15 ampere fuse F1 serves to protect the circuitry associated with the output stage of
the power amplifier. 5 ampere fuse F2 protects the primary circuitry for the isolated
24/12 volt DC/DC converter which provides the regulated, chassis referenced, +12
volt rail. The +12 volt rail powers the low level circuitry in the SEA 245. Each fuse
is individually protected from reverse polarity by power diodes CR1 and CR2 and
each power rail is individually filtered by 470 μF capacitors C29 and C47. Note that
these rails are NOT switched. Power is present on the power amplifier module and
the DC/DC converter input AT ALL TIMES.
5 ampere fuse F3 protects the regulated +12 volt primary power distribution system
in the SEA 245. Capacitors C75, C76 and C78 serve as line filters. The fused,
filtered +12 volt regulated rail is designated the +12VSW line and is distributed to
the SEA 245 circuitry through pins 5 and 6 of J8 on the PA/Filter Assembly.
(Ground and negative rail use pins 7 and 8).
5.6.3
THE MAIN POWER CONTROL CIRCUITRY
The main power switch in the SEA 245 is the ON/OFF switch located on the front
panel VOLUME control. Wires from the switch connect to J9 on the PA board
(ASY-0245-02). When the front panel switch is closed by rotating the VOLUME
control to the right from the stop, a connection is made between J10 pins 1 and 3.
This turns the 24/12 volt DC/DC converter ON and powers up the +12VSW rail in
the SEA 245.
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FCCID: BZ6SEA245
+
J6
F1,15A
+24VDC
CR1
J7
+24VCC
Q6,Q7
Q12
BIAS
PA GND
24/12V
DC/DC
CONV.
CONTROL
J10
F2,5A
U5
CR2
Q8,Q9
BIAS
+9V
U4
-12VSW
Q2,Q3
CHASSIS
+12VSW
+12VSW
Q1,Q4,Q5
F3,5A
Q14
ON/OFF
+12TX(PA)
J9
Q15
PA/FILTER
(ASY-0245-02)
U3
CHASSIS
ASY-0245-03
+10VTX
TX
+5V
RX
TXINT
J8
+10VTX
J6
+5V
13
TXEN
14
+12VSW
12VSW
RXEN
MAINBOARD
(ASY-0245-01)
GND
10
5,6
7,8
CHASSIS
Q30
Q28
+10V
+5V
+12TX
Q26
+12VRX
+3.3V
+5VAD
U36
U35
Q29
+5V
U38
U37
12VSW
SEA 245
Power Distribution Block Diagram
Figure 5.6.1
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5.6.4
+10 VOLT REGULATOR AND THE +10VTX SWITCH
The internal +10V rails are derived from the +12VSW bus through regulator U38.
The +10VTX rail is generated by inverted switch Q27. Grounding the notTXEN
line will turn on Q27, enabling the +10VTX rail. The notTXEN line comes from
the PA/Filter Assembly through pin 9 of J6.
5.6.5
+12 VOLT RAIL AND THE +12VTX/+12VRX SWITCHES
Transistors Q26 on the mainboard generate the mainboard +12VTX rail. The
+12VTX rail is energized when the notTXEN line from pin 9 of J6 goes low,
switching Q26 on.
The +12VRX rail is energized when the notRXEN line from pin 10 of J6 goes low.
This turns Q30 off which turns Q28 on, switching Q29 on.
The use of transistor switches to generate the TX and RX rails eliminates any
problems with relay contacts or T/R timing.
5.6.6
+5 VOLT REGULATORS
The +5 volt rail for the Mainboard Assembly and the PA/Filter Assembly is derived
from the +12VSW rail through regulator U37.
In the Front Panel/Controller Assembly (ASY-0245-03) a separate 5 volt regulator,
U16, provides the regulated rail for the controller circuitry. Note that the controller
+12VSW rail comes through the standard SEABUSS interconnection.
5.6.7
+3.3 VOLT REGULATOR
U36 on the Mainboard Assembly provides the +3.3V rail which is used in the
CPU/DSP Board (ASY-0245-04) to power the main control computer hardware.
5.6.8
+12VTX RAIL
The transmitter predriver circuitry and the bias systems for the transmitter driver are
supplied with a relatively high current +12VTX rail through Q14. Q14 is a PNP
power transistor, operated as an inverted switch. Base drive for Q14 is provided by
the INTERLOCKED notTX line. This line is obtained through the "safety clamp'
transistor, Q15, from the notTX and notRX ports generated by the controller
computer through the shift register U2 and the buffer chip, U3. When the notTX
port from pin 16 of U3 is LOW and the notRX port from pin 5 of U2 is HIGH, the
INTERLOCKED notTX line is LOW. This will cause Q14 to be ON, energizing
the +12VTX rail.
Note that the INTERLOCKED notTX line is also used to control Q26 and Q27, the
+12VTX and +10VTX switch transistors respectively, on the Mainboard Assembly.
The use of the INTERLOCKED NOT TX line in this fashion prevents the
simultaneous application of +12VTX and +12VRX to the low level transceiver
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circuitry.
5.6.9
THE +24VTX RAIL AND PA BIAS SYSTEM
Bias for the PA output transistors is generated from the +24VTX rail. Since the
entire +24 volt power source is isolated from the chassis, an optical isolator, U5 on
the PA/Filter Assembly (ASY-0245-02) is used to switch on a P-channel FET (Q12)
when the +12VTX rail is energized. This +24VTX line is then used to power bias
regulator transistor Q8 and the +9V PA bias supply regulator U4. The output from
U4 powers bias tracking amplifier transistor Q9. Q9 is a small power device which
is bonded to the same heat sink as the RF power transistors to provide thermal
feedback.
5.7
5.7.1
THE MAINBOARD CONTROLLER AND DSP PROCESSORS
GENERAL
The Mainboard microcontroller and digital signal processor (DSP) are contained on
a separate assembly (ASY-0245-04).
The microcontroller is a Motorola
MC68C812A4 operating from a 6.144 MHz clock. This is a low voltage (3.3V) 16bit processor with two asynchronous serial ports, a serial peripheral interface (SPI),
a timer and pulse accumulator module, an 8-channel 8-bit A/D converter, 1 Kbyte of
RAM, 4 Kbytes of EEPROM and memory expansion logic with chip selects. It also
has many bidirectional ports for general purpose I/O. The DSP is a TI
TMS32OVC5402. This is a 32-bit fixed-point DSP capable of 100 MIPS operation.
It includes 16 Kwords (16-bit) of internal RAM, two sophisticated multichannel
serial ports and a parallel host port interface.
5.7.2
BLOCK DIAGRAM
Figure 5.7.1 shows a block diagram of the processor assembly.
5.7.3
CLOCK DISTRIBUTION
The 12.288 MHz master clock is supplied through P2 to the processor assembly
(ASY-0245-04). U11A divides this clock by two to provide a 6.144 MHz clock to
the microcontroller, U5. U9 buffers the clock and converts it to a 1.8 volt level
suitable for the DSP, U7. The DSP has an internal PLL which generates a 98.304
MHz clock phase locked to the 12.288 MHz reference. The 98.304 MHz clock is
used as the cycle clock for the DSP and is also divided by 4 by U10 to produce a
24.576 MHz clock for the CODEC, U1. This clock divider can be reset by the DSP
in order to insure a known phase relationship between the CODEC clock and the
DSP clock. This is necessary for reliable communication between the CODEC and
the DSP.
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FCCID: BZ6SEA245
SEA 245 Processor Assembly
Block Diagram
Figure 5.7.1
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5.7.4
MICROCONTROLLER OPERATION
Reset generator, U8 provides a reset pulse to microcontroller U5 at startup or if
there is a dip in the power supply. At startup the microcontroller has access only to
the internal resources. It runs software contained in the internal EEPROM. This
software configures the chip and either boots a program from the RS-232 port
(Useful for service and reprogramming functions) or transfers control to the flash
memory. The flash memory contains most of the software for running the radio.
The radio channel list also resides in flash as well as software to be downloaded to
the DSP. A 64 kword external RAM is provided for workspace and stack space.
Additional memory for scratchpad channel storage and radio configuration
parameters is contained in the nonvolatile internal EEPROM. The microcontroller
may also communicate with the DSP as a memory-mapped device on the bus.
The processor has two asynchronous serial interfaces (SCI's). SCI0 is used to
provide an RS-232 interface to the radio which can be used for computer control or
for reprogramming the flash memory. SCI1 is used to provide a SEABUSS
interface to the front panel or a remote controller. The processor also has a serial
peripheral interface (SPI) which is used to communicate with the synthesizers as
well as a shift register which provides control signals to the PA/Filter Assembly.
The processor has an 8-channel analog to digital converter port. Not all of these
A/D converter channels are in use but some of them are used to read temperature
sensors, power sensors and synthesizer lock detection signal ports.
Finally there are quite a few general purpose I/O ports used to control the radio. For
example these are used to control gates to route audio signals, to communicate with
an Automatic Antenna Tuner, to control receiver gain steps, to switch the cooling
fan and the reset the DSP.
5.7.5
DSP OPERATION
At startup the DSP, U7, is reset by a port signal from the microcontroller, U5. The
microcontroller then transfers the firmware from the flash memory, U4, to the DSP
via the host port interface on the microcontroller's bus. This firmware runs out of
the DSP's internal RAM.
The DSP has two serial ports. One of these is used to communicate with the
previously described A/D converter on the Mainboard. This stereo 24-bit converter
samples signals from the Main Receiver and the Watch Receiver 96000 times per
second. During each sample two 24-bit words (One for each receiver) are
transferred over the serial port to the DSP. The DSP generates the 96KHz clock
which provides a framing signal to the A/D to select between the two channels. The
other serial port is connected to the CODEC, U1, which is described further below.
The interface is similar to the A/D interface but the sample rate is 48 KHz.
The operation of the DSP depends on whether the radio is receiving or transmitting.
When receiving the DSP reads receiver samples from the A/D. The digitized SSB
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FCCID: BZ6SEA245
samples are processed to convert them to the audio band, filter out undesired signals
and provide gain control and noise blanking. Watch Receiver signals are also FSK
demodulated in order to detect Digital Selective Calling (DSC) data. Audio samples
from the Main Receiver are passed to the speaker audio circuit through the CODEC
monophonic output. DSC data is passed to the microcontroller over the host port
for further data decoding. In transmit mode microphone audio samples are read by
the DSP from the CODEC, U1. the DSP performs speech processing on these
samples and converts them to inphase and quadrature signals at an IF of
approximately 15 KHz. These I and Q samples are transferred to the I/Q Modulator
through the CODEC.
In both transmit and receive modes, the DSP also communicates regularly with the
microcontroller over the host port. In receive mode the DSP regularly sends gain
information to the microcontroller as well as DSC data. In the transmit mode the
DSP must obtain power sensor data from the microcontroller in order to implement
Automatic power Level Control (ALC). The DSP also receives mode information
from the microcontroller which determines operating parameters of the DSC such
as PTT status, transmitter power level and receiver bandwidth.
5.7.6
CODEC OPERATION
U1 is an AC '97 compliant 18-bit stereo CODEC operating with a 48 KHz sample
rate. On board multiplexers can select between two stereo inputs and three mono
inputs. It also has selectable stereo or mono outputs. Each channel has independent
gain and mute controls. All of the control and status as well as the stereo input and
output sample data is passed over the serial connection to the DSP. the stereo
output is used for transmit I and Q samples for the modulator. The mono output is
used for speaker audio. Two of the inputs are used for microphone audio and an
alternate low level audio input. The other input channels are not used.
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FCCID: BZ6SEA245
6
6.1
THE SEA 245 FRONT PANEL/CONTROLLER SYSTEM
GENERAL
The SEA 245 Front Panel/Controller unit is a complete SEABUSS controller and is
designed in such a manner as to permit direct installation on the front of a standard
SEA 245 as well as in remote installations. The SEA 245 will support a SINGLE
remote controller and a SEABUSS compatible Antenna Tuner such as the SEA
1631. The maximum TOTAL length of SEABUSS cable not to exceed 200 feet (60
meters). The stand-alone Controller (SEA 2450) is designed for shipboard
mounting. Keypad and display are backlighted for operator convenience
Figure 6.1 shows the outline dimensions of the SEA 2450 with mounting bracket.
For information regarding flush mounting, contact the SEA, Inc. factory.
Interconnection between the Front Panel/Controller and the SEA 245 Mainboard
Assembly (ASY-0245-01) when the Controller is directly attached to the
radiotelephone is through an 8-pin DIP connector which carries the standard
SEABUSS interface connections (See Front Panel/Controller (ASY-0245-03)
schematic diagram). This connector (P1) connects to connector J3 on the
Mainboard Assembly (ASY-0235-01) through a short, 8 conductor ribbon cable.
Remotely located Controllers use the standard 9-pin Phoenix style SEABUSS
connector and interconnection is, as stated above, through standard SEABUSS cable
(CAB-2350-XX). The recommended cable is designed to provide adequate
interconnection for the +12VSW line and the PTT line, as well as providing two
shielded, twisted pairs to support the SEABUSS audio circuit and the SEABUSS
data circuit. Note that all SEABUSS cable interconnections are pin-for-pin and that
the shielded twisted pairs are used for audio and data interconnection. See Figures
4.5 and 4.6 for details regarding system interconnections.
6.2
THEORY OF OPERATION
Figure 6.2 shows a block diagram of the Front Panel/Controller Assembly.
The controller(s) are essentially "dumb terminals" configured specifically as the
front panel of a Single Sideband Transceiver. Radiotelephone functions are
controlled by the keypad, transceiver parameters are indicated by the liquid crystal
display (LCD), microphone audio is processed by the circuitry on the Front
Panel/Controller PC board and then routed to the transceiver circuitry through the
SEABUSS audio interconnection, and receiver audio is received from the
transceiver through the SEABUSS audio interconnection and then processed
through the volume control, squelch gate and loudspeaker amplifier to the
loudspeaker.
The controller circuitry is contained on the Front Panel/Controller PC assembly
(ASY-0245-03). This printed circuit board contains the keyboard interface,
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FCCID: BZ6SEA245
microphone audio to SEABUSS and SEABUSS to loudspeaker audio circuitry, the
LCD display and display driver circuitry and the controller CPU.
The primary power source for the Front Panel/Controller Assembly is the +12VSW
bus from the SEA 245 Mainboard Assembly. This power bus is part of the
SEABUSS interconnection.
Most of the Front Panel/Controller circuitry operates from a +5 volt regulated line
derived from the +12VSW rail through regulator, U16. The SEABUSS PTT line is
a buffered output from the Front Panel/Controller board CPU. When the controller
microphone requests PTT, the controller CPU processes this request and signals the
SEA 245 Mainboard Assembly through buffer amplifier Q7.
6.2.1
KEYBOARD SUPPORT
The SEA 245/SEA 2450 keyboard has a total of 19 keys. Key status is determined
by scanning the matrix through control lines from the CPU chip, U1.
6.2.2
THE LCD DISPLAY AND DISPLAY LIGHTING
DISPLAY: The front panel display is a LED backlighted LCD graphic module.
Various display configurations are provided which permit the operator to monitor all
the various radiotelephone parameters such as channel number, power level,
memory mode, etc. The display is controlled by the Front Panel/Controller
microprocessor, U1. Display contrast is controlled through U1 by a voltage level
from D/A converter chip U6 and operational amplifier U17A. This trimming
voltage is applied to Vo (Pin 3 on connector P7).
BACKLIGHTING: Similarly, the backlighting level is controlled through
microprocessor U1 by a voltage level from D/A converter chip U6 and emitter
follower Q2. This control voltage is applied to the base of control transistors Q3
and Q4. Varying the control voltage will vary the current through the backlighting
LEDs, thus adjusting the backlight level.
6.2.3
THE SQUELCH FUNCTION
In the SEA 245/SEA 2450, the squelch function is a software voice-operated
"constant SINAD" squelch system which functions by examining the audio stream
to determine the presence of a voice signal.
A sample of the receiver audio from the SEABUSS audio receiver (U10A) is
amplified and limited by U9A/B, processed by the software routine running in U1
and used to control the audio to the volume control. When the squelch program
senses that a signal is present, the control signal to the gate of shunt transistor Q6
goes LOW, permitting audio to pass. Although the computer controlled squelch is
relatively immune to changing noise conditions, in some cases it may be
advantageous to reset the squelch trigger threshold. This is a software function and
may be accomplished through the keypad. (See operator's instructions).
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FCCID: BZ6SEA245
6.2.4
BILATERAL AUDIO CIRCUITRY
The receiver audio path in the Front Panel/Controller Assembly is from the bilateral,
balanced SEABUSS audio terminals (P1, Pins 6 and 7), through the balanced to
unbalanced audio line receiver (U10A), the squelch gate (Q6), the volume control
(R2) and the audio power amplifier (U14) to the loudspeaker. The squelch limiter
(U9A and U9B) connects to the audio upstream of the squelch gate. The hard
limited output of the limiter is connected to the input of the controller CPU, U1.
The transmitter audio path is from the microphone to the microphone mute
transistor (Q5) and from there on to the microphone amplifier/SEABUSS driver
consisting of U10C and U10D. SEABUSS audio level is nominally 2.0 volts peakto-peak (0dBm).
6.2.5
SEABUSS DATA CIRCUITRY
The serial data stream which links the controller(s) and the transceiver connects to
the controller(s) at P1, Pins 4 and 5. The data transducer is a bidirectional data
transceiver (U6) which uses a bi-phase data format similar to RS485. On each end
of the data path, the data
transceivers are connected to the system CPU boards
through the Sout and Sin pins on the data transceiver. Communications between the
controller(s) and the SEA 245 Mainboard Assembly are bidirectional and fully
interactive. This means that when the SEA 2450 Remote Controller is used, the
status of the SEA 245 is reflected at both operating stations. Controller-SEA 245
data is sent in packets and is error checked. Collision protection is provided for all
data sources. Baud rate is 9600 bps. For further data on the format of the
SEABUSS command structure used in the SEA 245, contact SEA, INC. at 7030
220th St. S.W., Mountlake Terrace, WA, 98043. Or call (425) 771-2182.
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