Codan Radio Communications AMP-3-150 AMP-3/140-30 & AMP-3/160-30 User Manual IM71 AMP3150 30 indb
Codan Radio Communications AMP-3/140-30 & AMP-3/160-30 IM71 AMP3150 30 indb
Manual
Copyright © 2003 Daniels Electronics Ltd. All rights reserved. No
part of this publication may be reproduced, stored in a retrieval system
or transmitted in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without the prior written consent
of Daniels Electronics Ltd.
DE™ is a registered trademark of Daniels Electronic Ltd. registered in
the U.S. Patent and Trademark Offi ce.
Document Number:
Revision:
Revision Date:
Daniels Electronics Ltd.
Victoria, BC
PRINTED IN CANADA
VHF 30W
POWER AMPLIFIER
INSTRUCTION MANUAL
AMP-3/150 136-174 MHZ
Covers Models:
AMP-3/140-30 AMP-3/160-30
IM71-AMP3150-30
1-1-0
Nov 2003
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
ii
This document has been produced, verifi ed and
controlled in accordance with Daniels Electronics’
Quality Management System requirements.
Please report any errors or problems to Daniels
Electronics’ Customer Service Department.
The user’s authority to operate this equipment could
be revoked through any changes or modifi cations not
expressly approved by Daniels Electronics Ltd.
The design of this equipment is subject to change
due to continuous development. This equipment may
incorporate minor changes in detail from the information
contained in this manual.
DOCUMENT CONTROL
NOTE
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
iii
RF Exposure Warning
Exposure to radio frequency (RF) energy has been identifi ed as a potential environmental factor that must be
considered before a radio transmitter can be authorized or licensed. The FCC has therefore developed maximum
permissible exposure (MPE) limits for fi eld strength and power density, listed in FCC 47 CFR § 1.1310. The
FCC has furthermore determined that determination of compliance with these exposure limits, and preparation
of an Environmental Assessment (EA) if the limits are exceeded, is necessary only for facilities, operations and
transmitters that fall into certain risk categories, listed in FCC 47 CFR § 1.1307 (b), Table 1. All other facilities,
operations and transmitters are categorically excluded from making such studies or preparing an EA, except as
indicated in FCC 47 CFR §§ 1.1307 (c) and (d).
Revised FCC OET Bulletin 65 (Edition 97-01) provides assistance in determining whether a proposed or existing
transmitting facility, operation or device complies with RF exposure limits. In accordance with OET Bulletin 65
and FCC 47 CFR § 1.1307 (b), this Daniels Electronics Ltd. transmitter is categorically excluded from routine
evaluation or preparing an EA for RF emissions and this exclusion is suffi cient basis for assuming compliance
with FCC MPE limits. This exclusion is subject to the limits specifi ed in FCC 47 CFR §§ 1.1307 (b) and 1.1310.
Daniels Electronics Ltd. has no reason to believe that this excluded transmitter encompasses exceptional
characteristics that could cause non-compliance.
Notes: • The FCC’s exposure guidelines constitute exposure limits, not emission limits. They are relevant to
locations that are accessible to workers or members of the public. Such access can be restricted or
controlled by appropriate means (i.e. fences, warning signs, etc.).
• The FCC’s limits apply cumulatively to all sources of RF emissions affecting a given site. Sites
exceeding these limits are subject to an EA and must provide test reports indicating compliance.
RF Safety Guidelines and Information
Base and Repeater radio transmitters are designed to generate and radiate RF energy by means of an external
antenna, typically mounted at a signifi cant height above ground to provide adequate signal coverage. The
following antenna installation guidelines are extracted from Appendix A to OET Bulletin 65 and must be adhered
to in order to ensure RF exposure compliance:
Non-building-mounted Antennas:
Height above ground level to lowest point of antenna ≥ 10 m or
Power ≤ 1000W ERP (1640 W EIRP)
Building-mounted Antennas:
Power ≤ 1000 W ERP (1640 W EIRP)
The following RF Safety Guidelines should be observed when working in or around transmitter sites:
• Do not work on or around any transmitting antenna while RF power is applied.
• Before working on an antenna, disable the appropriate transmitter and ensure a
“DO NOT USE” or similar sign is placed on or near the PTT or key-up control.
• Assume all antennas are active unless specifi cally indicated otherwise.
• Never operate a transmitter with the cover removed.
• Ensure all personnel entering a transmitter site have electromagnetic energy awareness
training.
For more information on RF energy exposure and compliance, please refer to the following:
1) FCC Code of Regulations; 47 CFR §§ 1.1307 and 1.1310.
2) FCC OET Bulletin 65, Edition 97-01, “Evaluating Compliance with FCC Guidelines for
Human Exposure to Radiofrequency Electromagnetic Fields”.
3) http://www.fcc.gov/oet/rfsafety/
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
v
Contents
General Information ...............................................................1
Introduction ................................................................................................1
Performance Specifi cations .......................................................................2
Physical Specifi cations ..............................................................................3
Theory of Operation ...............................................................5
General ......................................................................................................5
Amplifi er PCB Circuitry ..............................................................................5
Control PCB Circuitry................................................................................. 6
Alignment & Installation .........................................................9
Recommended Test Equipment ................................................................. 9
Amplifi er Board Alignment..........................................................................9
Control Board Alignment .......................................................................... 10
Power Amplifi er Installation...................................................................... 11
Illustrations and Schematics ................................................ 13
VHF 30W Power Amplifi er Block Diagram ............................................... 14
VHF 30W Power Amplifi er Exploded View Diagram ................................ 15
VHF 30W Power Amplifi er RF AMP Board Component Layout (Top)...... 16
VHF 30W Power Amplifi er RF Amp Board Schematic ............................. 17
VHF 30W Power Amplifi er Control Board Component Layout (Top)........ 18
VHF 30W Power Amplifi er Control Board Schematic .............................. 19
Parts List .............................................................................. 21
Amplifi er Board Electrical Parts List......................................................... 21
Control Board Electrical Parts List ........................................................... 24
Mechanical Parts List............................................................................... 26
Revision History ................................................................... 27
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
1
GENERAL
INFORMATION
INTRODUCTION
The MT-2/MT-3/MT-4 repeater system is a
VHF/UHF radio system which is characterized
by high performance and reliability under the
most severe environmental conditions. The total
system is designed to provide dependable, low
maintenance performance, even in the most
diffi cult circumstances.
The MT-2/MT-3/MT-4 series of modules are
packaged in the compact Eurostandard
(5”h x 2.8”w x 7.5”d) housing, and are robustly
designed for urban, remote or transportable
applications. Voltage stress testing is done
over the range of +10 to +17 Volts DC which is
followed by 24 hours of continuous operation at
maximum rated power output.
When the VT-2/VT-4 transmitter is used as an
exciter for the VHF AMP-3 power amplifi er (PA)
module, it will provide an adjustable 10 to 30
Watts RF output over the 136 to 174 MHz VHF
Frequency range. When the VT-3 transmitter
is used as an exciter the RF output is only
adjustable from 20 to 30 Watts.
The VHF AMP-3 family contains two models
(AMP-3/140 and AMP-3/160) covering two
frequency bands 136 - 150 MHz and 150 - 174
MHz, respectively. The VHF AMP-3 power
amplifi er (PA) mates with either the MT-2 VHF
transmitter exciter module, the VT-3/1xx-Sx
transmitter exciter module or the VT-4x1xx-x0
transmitter exciter module.
VHF 30W Power Amplifi er Instruction Manual
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General Information
2
PERFORMANCE SPECIFICATIONS
Type: MT-3 Series Power Amplifi er
Family: AMP-3/150
Models: AMP-3/140, AMP-3/160
Compatibility: MT-2, MT-3 and MT-4 Series Transmitter Exciters
Frequency Range: 136 to 174 MHz
Frequency Bands: 136 to 150MHz, 150 to 174MHz
RF Input Power: 2 - 3.5 Watts (not to exceed 4W)
RF Output Power: Adjustable: 10-30 Watts (set by MT-2 or MT-4 exciter)
Adjustable: 20-30 Watts (set by MT-3 exciter)
Nominal Passband Gain: 10dB
Output Impedance: 50 Ω, Type N connector
Output Return Loss (VSWR): Better than 21 dB (1.2)
Input Return Loss (VSWR): Better than 18 dB (1.3)
Conducted Spurious & Harmonics: < -80 dBc (at 30W output)
Less than 0.3 uW (-35 dBm) absolute level
Operating Voltage: +13.8 VDC nominal, range +10 to +17 VDC
Transmit Current: 3.0 to 5.0 A @ 30 W
Standby Current: < 5 mA
Thermal: Thermal interlock disables @ 80ºC (175˚F)
Fan activated @ 40ºC (105ºF)
Duty Cycle: Continuous (with Fan) -40ºC to +60ºC Operation
Exciter VT-2, VT-3 and VT-4 4W max. output for 30 W P.A
IC TAC: pending
FCC ID: pending
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
General Information 3
PHYSICAL SPECIFICATIONS
Operating Temperature Range: -30ºC to +60ºC, optional -40ºC temperature test.
Operating Humidity: Up to 95% RH (non-condensing) at +25ºC
RF Connectors: Type N Standard
Corrosion Prevention: Anodized aluminum construction. Stainless steel hardware.
Physical Dimensions: Width: Height: Depth:
14.2 cm (5.6”) 12.8 cm (5.05”) 19 cm (7.5”)
Weight: 2.4 kg. (5.5 lb.)
Features: •Heavy Duty Aluminum Heatsink;
•Thermal switched Fan (at 40ºC).
•RF Power, High VSWR, Overload and Overtemp Indicators.
•Internal, re-settable circuit breaker
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
9
ALIGNMENT
& INSTALLATION
RECOMMENDED TEST
EQUIPMENT
Daniels Subrack SR-39-1 with System Monitor
Daniels Extender Card Kit EC-48RK
Power Supply Regulated 13.8VDC @ 10A
Current Meter 5.0A
DC Voltmeter
RF Coupler (eg. Bird 4275)
Wattmeter (eg. Bird 4421)
VSWR Meter (eg. Bird 4421)
Dummy Loads 50 Ohm, 3:1 (50W)
Spectrum Analyzer (eg. IFR 2975)
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
Alignment & Installation
10
AMPLIFIER BOARD
ALIGNMENT
Refer to the VHF 30W Power Amplifi er Board
Component Layout Diagram for the location of
the adjustment capacitors, potentiometers, air-
core coils and test points.
This procedure assumes the use of a single
subrack with an EC-48RK extender card kit for
both the exciter and the power amplifi er such
that their internal adjustment points are easily
accessible.
Step 1: Remove the top extrusion cover from
the transmitter exciter. Set the exciter frequency
to either 143MHz or 162MHz depending upon
whether you are tuning a lowband or highband
unit, respectively.
Step 2: Install one of the extender cards in the
designated location for the exciter within the
subrack. Connect the exciter to this extender
card using the gray connector cable provided
with the extender card kit.
Step 3: Refer to the ‘VHF 30W Power Amplifi er
Exploded View’ on page 15 for help on the
following procedures. Remove the power
amplifi er 14HP case. Next, unplug the cooling
fan from the control board and remove the front
panel. Using suitable male connectors or a test
jig, apply the following signals directly to the
amplifi er board:
• 13.8V : J3 - Pin1, Pin 2
Note: Ensure an ammeter is connected in
series with this line.
• Gnd : J3 - Pin 3, Pin 4
• 9.5V : J4 - Pin 4
• Gnd : J4 - Pin 8 (RF Input Sample)
Step 4: While monitoring the current on the
13.8V line and without an RF input to the power
amplifi er, slowly adjust the potentiometer RV1
until the current reads 230mA. As a check,
measure the voltage at TP1. It should read
between 2.5V and 3.0V.
Step 5: Now connect the output of the exciter
to the input of the power amplifi er. Connect the
output of the power amplifi er through a suitable
RF coupler then through a power meter and
fi nally terminate the output with a 50 Ohm load.
The low power output from the RF coupler
should be connected to the input of a spectrum
analyzer. The spectrum analyzer should have
an output tracking generator capable of putting
out at least a +6dBm signal. This output should
be connected to the input of the exciter amplifi er
which is fi rst disconnected from the exciter’s
local oscillator.
Step 6: Before enabling the tracking generator,
the output power of the exciter amplifi er should
be disabled by turning its potentiometer fully
counterclockwise (~12 Turns). Now turn the
exciter on by setting the front panel switch
to ‘Key Tx’. Set the center frequency on the
spectrum analyzer to the same frequency the
exciter was set to in Step 1. Next, set the span
to 0 Hz and enable the tracking generator with a
+6dBm output.
Step 7: While monitoring the output on the
power meter and ensuring 13.8V on the PA
amplifi er board, slowly increase the exciter
amplifi er output until 30W is reached. Increase
the span on the spectrum analyzer to 20MHz.
Next, remove the cover on the low-pass fi lter
shield (10601-01) on the amplifi er PCB to
allow access to the air-core inductors, L5 to L8.
Monitoring the output response on the spectrum
analyzer, tune these inductors by altering the
spacing between the windings with a plastic
adjusting tool for maximum fl atness and gain
across the desired band (136 - 150MHz for
lowband, 150 - 174MHz for highband). Then
capacitor C12 should be adjusted for maximum
fl atness and gain also.
Step 8: Set the span on the spectrum analyzer
to 0 Hz and check that output VSWR is
below 1.20 on the band edges and the center
frequency of the band.
Step 9: As a fi nal check, replace the low-pass
fi lter shield and using the spectrum analyzer
again, search the band (either 136 - 150MHz
or 150 - 174 MHz) for any unwanted spurious
emissions.
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
Alignment & Installation 11
CONTROL BOARD
ALIGNMENT
Refer to the VHF 30W Power Amplifi er Control
Board Component Layout Diagram for the
location of the adjustment potentiometers and
test points.
This procedure assumes the use of 1/2
wavelength RF output cables between all
pieces of test equipment after the PA output for
accurate power readings during mismatched
load conditions.
Step 1: Once the amplifi er board alignment is
complete, the exciter can be turned off and its
amplifi er re-connected to the local oscillator.
Next, the male connectors or test jig can be
removed from the amplifi er board and the
control board along with the front panel can be
re-connected to the power amplifi er. The power
amplifi er can then be connected via the gray
cable to the second extender card which should
be installed in the designated location within the
subrack for the power amplifi er.
Step 2: With the exciter’s output still connected
to the input of the power amplifi er and the
output of the power amplifi er still connected
through an RF coupler into a wattmeter and
50 Ohm load, set the transmitter to the desired
frequency. Next, adjust the output power of the
exciter such that the PA output is 10W. Then
adjust potentiometer RV1 until LED1, or the ‘RF
POWER’ indicator, just turns on. This threshold
may be adjusted to any RF output power level
between 10W and 30W.
Step 3: Set the exciter output power such that
the output power from the PA is equal to that
under normal operating conditions. Replace
the 50 Ohm load with a suitably rated 3:1
mismatched load. Adjust potentiometer RV2 until
LED2, or the ‘HIGH VSWR’ indicator, just turns
on.
Step 4: As a check, terminate the power
amplifi er once again with a 50 Ohm load and
ensure that LED2 is now off. If it is not off, adjust
RV2 until LED2 just turns off. Doublecheck
that the LED still activates when the output is
terminated with a 3:1 load. This threshold may
be adjusted with a 3:1 on the output of the PA
anywhere from 10W to 30W out.
Step 5: Disconnect the RF termination on the
PA such that the output is an open load. Activate
the exciter then adjust potentiometer RV3 until
LED3, or the ‘OVERLOAD’ indicator, just turns
on. When this occurs the output power is also
substantially reduced to help protect the RF
transistor. If the overload LED is turning on
without having to adjust RV3, power down the
exciter re-adjust RV3 and re-activate the exciter.
This confi rms that antenna VSWR overload
protection works correctly.
NOTE: The above three pots, RV1 to RV3, on the control
board should be re-checked and possibly re-adjusted if any of
the following changes are applied to the unit:
• The output power level is changed
• The frequency is changed
• The output cable length is changed
POWER AMPLIFIER
INSTALLATION
The AMP-3/150 RF power amplifi er is designed
for operation with any of the Daniels MT-2, MT-
3 or MT-4 VHF transmitter exciters. A complete
SR-3 subrack shipped directly from the factory
is normally set to the appropriate options and
output power calibration as requested by the
customer. These units require no tuning.
For AMP-3/150 amplfi iers shipped separately
from the SR-3 subrack, install as outlined:
- Connect +13.8V DC Power Supply to subrack
- Connect the output of the exciter to the input of
the VHF 30W PA with the cable provided
- Connect the antenna system (using a 1/2
wavelength cable if possible), turn on the PA
and key the transmitter. The ‘RF POWER’ LED
should light and the other three LED indicators
should remain off.
The LED indicators will only illuminate when the
power amplifi er is on and are defi ned as follows:
-RF POWER - Indicates that the minimum preset
RF power level is present at the power amplifi er
output. The threshold is internally adjustable
for RF output levels in the 10-30 watt range
(Factory set at 10W).
- HIGH VSWR - Alarm indicating that the load
impedance mismatch is higher than the preset
level. The threshold is internally adjustable for
load mismatches from 2:1 to an open output
(Factory set at 3:1).
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
Alignment & Installation
12
Note: The proper setting of this indicator cannot
be guaranteed if a non-1/2 wavelength cable
is used between the output of the PA and the
antenna.
- OVERLOAD - (VSWR Overload Alarm) is used
to indicate that the load impedance mismatch
is extremely high and could potentially damage
the RF transistor. Under this condition, the gate
voltage to the transistor is dropped thus reducing
the RF output power and preventing damage to
the MOSFET. The factory threshold level is set
when the load terminal is open.
- OVER TEMP - (Over Temperature alarm) a
thermostat control switch interrupts the DC
supply voltage to the PA when the RF transistor
body temperature exceeds 80ºC (175ºF).
Utilizing circuit hysteresis, the thermostat will
reset at 75ºC (167ºF).
The fan is activated automatically when the
RF transistor body temperature reaches
approximately +40ºC (104ºF). The fan’s
operating temperature range is -20ºC (68ºF)
to +60ºC (140ºF). It will not operate when the
ambient temperature is below -20ºC (68ºF).
VHF 30W Power Amplifi er Instruction Manual
IM71-AMP3150-30
27
REVISION
HISTORY
Revision Date ECO Description
1 Apr 2003 First Revision
1-1-0 Oct 2003 Complete update of manual and drawings.