BEI Electronics STL-20W-950S STL Transmitter User Manual users manual 1

Download:
Mirror Download [FCC.gov]
Document ID	177881
Application ID	2FbCEmYEItFFFsiH6DXUJw==
Document Description	users manual 1
Short Term Confidential	No
Permanent Confidential	No
Supercede	No
Document Type	User Manual
Display Format	Adobe Acrobat PDF - pdf
Filesize	153.14kB (1914278 bits)
Date Submitted	2001-11-06 00:00:00
Date Available	2001-11-02 00:00:00
Creation Date	2001-10-31 16:19:24
Producing Software	Acrobat 4.05 Scan Plug-in for Windows
Document Lastmod	2001-11-01 16:02:19
Document Title	users manual 1
Document Creator	Acrobat 4.05 Scan Plug-in for Windows

COMPOSITE
STL TRANSMITTER
MODEL STL-200
Introduction
Specifications ...............................................................................................................
Unpacking and Inspection
Installation ...................................................................................................................
Electrical Connections ..........................................
STL System (Stereo and Mono) Block Diagram, No. 702-096 ....................................
Antennas ...............................................................................
Operation .................................................................................................................
System Performance Tests .................................................................................
Theory ofOperan‘on ....................................................................................
Tools and Test Equipment Required ............................................................................
Transmitter Test Report ...............................................................................................
Tune-Up and Adjustment ............................................................................................
Sending an Instruction
Block Diagram, STL~20C
Adjustment Locations Diagram, STL20C
Main Frame Schematic
Frequency Dip-Switch Settings
Board Schematics and Parts List
10
13
15
17
1s
19
24
26
27
28
29
49
The Marti STL-20C Transmitter with companion R-lSC Receiver, form a high quality, fre-
quency synthesized, point-to-point, line of sight, radio communications link. This system is
available in the frequency band from 940 MHz to 965 MHz and will soon be available in all STL
bands from 140 MHz and up. Depending upon available channel bandwidth, these systems can
transmit one of the following:
0 Composite FM Stereo audio with two subcarriers"
. Monophonic audio with two subcarriers
- Digital stereo audio (requires external modems)
- Multi-channel audio or data (requires external MUX)
. Digital data (requires external modems)
Complex systems can be built from basic STL-ZOC transmitters and R-15C receivers having
multiple relay (repeaters), bidirectional (full duplex), and automatic switching hot standby
features.
The STL-2OC offers new features not found in other 950 MHz STL’s:
- 20 Watts output power - adjustable
. Frequency agile — 25 MHz wide — 25 KHz steps
. No tuning
. High speed embedded mierocontroller
. Automatic level control of output power
- High VSWR and high temp protection
THIS EQUIPMENT MUST BE OPERATED WITH A 3-PRONG
GROUNDED OUTLET RECEPTACLE. FAILURE TO USE A
PROPERLY GROUNDED OUTLET MAY RESULT IN IMPRO-
PER OPERATION OR SAFETY HAZARDI
LIMITED WARRANTY
The Seller warrants that, at the time of shipment, the
productsmanufirchxredbytheSellerarefi'eefi'om
defects in material and workmanship. The Seller‘s
obligation under this warranty is limited to replace-
mentorrepair ofsuah products whichureretumed to
Marti at its fictcry, transportation prepaid and
properly insured, provided:
a. Notice of the claimed defect is given to Marti
within one (1) year [two (2) years for STL systems]
from date of original shipment and goods are returned
in accordance with Marti instructions,
b. Equipment, accessories, tubes and batteries not
matmfaowredbyMnniaresuhjecttoonlywchad—
justments as Marti may obtain fi'om the supplier
thereof.
c. This warranty does not apply to equipment which
has been altered, improperly handled, or damaged in
any way.
The Seller is in no event liable for consequential
damages, installation cost or other costs of any numre
summit oftheuseoftheproducts nmnufactured or
supplied by the Seller, whether used in accordance
with instructions or not,
Thiswamnty isin lint ofall others, eitherexpressed
or implied No representative is authorized to assume
for the Seller any other liability in connection with
Seller's products,
MAILING 8; SHIPPING ADDRESS:
MART! Electronics
PO, Box 661 421 Mani Drive
Ciebume, Texas 76031—0661
The United States of America
COPYRIGHT NOTICE
©1993 All nghh Reserved
Marti Electronics
7th printing, May 1997
No part of this mutual may be repmdumd,
transmitted, transcribed, stored in a retrieval system ,
or translated into any language, natural or computer,
in any form or by any means, without the prior written
permission charti Electronics,
Artwork depicting circuitry in dis manual is protected
by copyright laws.
Information in this manual is subject to chmge
without notice and does not represent a commitment
on the part of Marti Electronics,
Marti Electronics may make improvements and/or
changes in this manual or in the product descn‘bed
herein at any time.
This product could include technical inaccuracies or
typographical errors.
PHONE NUMBERS:
Sales & Service (817) 645-9163
FAX (817) 641-3869
IMPORTANT NOTICE
This equipment must be operated in a
well-ventilated rack cabinet.
install rack-mounted equipment in
a well-ventilated, well-grounded, and
shielded rack cabinet. Do not locate
solid-state equipment in a rack above
tube-type equipment which produces
high temperatures.
Problems can also be avoided by
locating this unit away from other
equipment which has transformers
that produce strong magnetic fields.
These fields can induce hum and
noise into the Marti equipment thus
reducing performance. Strong radio-
frequency (RF) fields should be
avoided where possible. Extensive
shielding and filtering have been
incorporated into this equipment to
permit operation In moderate RF
environments. All equipment racks,
cabinets, etc., should be bonded
together by wide copper grounding
strap to ensure that all system
elements are at RF ground potential.
Transmitter connections for
Composite Stereo operation
(Rater to Drawing 102-098)
1. The composite signal output fi'om a stereo gerr-
erator is connected to the BNC jock labeled ”JZ
comm ", The input impedance is 5K ohms
and the composite signal level should he 3 volts peak-
to-peak or approximately 1 volt RMS, The final level
adjustment is set for 100% peak modulation indica-
tion on the MODULATION bar graph meter on the
STL-lSC front panel,
2, A subcarrier generator or remote control
(operating above 92 KHz) can be connected to ”It or
J3 SUBCARRIER" jack. The ability of the STL-ZOC
system to transmit subcarriers depends upon the
channel bandwidth available. The R-lSC receiver lP
filter selectivity must be compatible with the available
interference free channel bandwidth. Using 50 KHz
deviation for 100% moduhtion, the apprordmare
bandwidth required for various subcarriers follows:
Actual bandwidth may require an additional 10%
to 15% to allow for the modulation on the subcan'ier
itself, With the severe STL channel crowding with
resulting interference prevalent around large markets,
subcarriers above [10 KHz are not recommended.
3. The accessory connector has several uses such as
remote control, automatic switching, and external DC
power. Connection instructions are fumished with
time accessories,
4. Connect 511. transmitting antenna coax to "JG
ANTENNA“. This requires a type N male
connector. A short flexible jumper (20" max.)
may be used between J6 and sen'ri-t'le7dblo warn
Marti Part No. 585-017 double shielded, low-
loss RG 214/U jumper is recommended.
5. Turn transmitter ofl‘t Connect AC line receptacle
on back of the transmitter to a 115 volt AC
power source with special cord set supplied. USE
ONLY 3-PRONG GROUNDED OUTLET
RECEHACLES FOR SAFETY.
WARNING
This equipment must be operated with a 3-
prong, grounded, 115 volt, AC outlet
receptacle! Failure to use a properly
grounded outlet could result in a safety
hazard or faulty equipment performance!
Transmitter connections for
Monophonic operation
(Refer to Drawing 701-096)
l, Monophonic program audio output is connected
to balanced audio input screw tenninals Use shielded
wire Prognmnudiolevelrequiredisi-B dBm, 600
ohms balanced and isolated from ground. For dual
channel stereo repeat instructions at second
transmitter. Audio processing requirements will be
dismissed in the “OPERATION“ section of this
mnnuaL
2. Connect a remote control or subcan-ier generator
(medium) to the jack marked, “11 or J3 sun in",
The mbcsrriet source may he 50 to SK ohms
impedance, and the input level required is
approximately one (1) volt RMS. System factory
supplied with 250 RH: IF bandwidth will any
subcerriers up to 92 KHz. For other subcarrier
frequencies or narrow lF bandwidth systems contact
the factory. A second subcmier generator can be
cormed to "JS", If; dual channel stereo $11. is
used connect one subcanier generator to “Jl” or “13”
on each channel's transmitter,
3. The accessory connector has several uses such as
remote control, automatic switching, and external DC
power, Connection instructions are finished with
these accessories.
4. Connect STL transmitting antenna coax to, 16
ANTENNA This requires a type N male connector
A short flexflale jumper (20" max.) may be used
between 16 and semi-flexible coaxr Marti Part No.
585017 double shielded, low-loss RG~214IU jumper
is recommended
5. For dual channel stereo, use only Marti Part No
585017 double shielded, low-loss RG-ZM/U
jumpersbetweenJfiofeachtransmitter-anddre
indicated connectors of the HRC-lo Series
Combinersr Use a third Pm No. 585-017 jumper
between the ANTENNA connector of the HRC-lo
and the semi-rigid coax. Refer to Drawing 702-096.
6. Tum transmitter ofl', Connect AC line receptacle
on back ofthe msmitterto a 115 volt AC power
source with special cord set supplied, USE ONLY 3-
PRONG GROUNDED OUTLET RECEPTA-
CLES FOR SAFETY.
WARNING
This equipment must be operated with a 3-
prong, grounded, 115 volt, AC outlet
receptacle! Failure to use a properly
grounded outlet could result in a safety
hazard or faulty equipment performance!
The following suggestions are offered to help
those responsible for antenna installations avoid
costly errors in assembly and adjustment Marti
Electronics, Inc. assumes no responsibility for the
installation and performance of antenna systems
associated with its equipment. The following
suggestions are not intended to he a complete step-
by-rtep procedure, simply a listing of some a! the
most frequently reported errors in antenna system
installation.
Antenna Assembly
Follow the manufacturer's instructions carefully
Ifno instructions were included with the antenna, call
or write the antenna manufacmrer for instnwtions.
Errors are fiequently made in assembly of the RF feed
dipoleelementswhichnmstbeinstalledinthesame
plan as the reflector grids. In other words, if the
reflecwrgi‘iddememsmhofiMMthenthefeed
dipole elements nmst also be horizontal. Cross
polarization of grid and feed dipole will result in total
loss of antenna gainl.
Transmlssion Llne Connector
Assembly
Do not use RG~58 U or RG-S U cable for STL
station antennas! They have too much loss at VHF
and UHF fi'equenoies. Follow the instructions
fumished by the manufincturer when wtting coaxial
cable. Inspect the cable ends for small metal
fragments which can short-circuit the line inside the
contractor assembly. Check the line for a short-circuit
condition alter each cormector is installed by using an
ohmmeter. Pressurized line should be checked for
several days under pressure before installation on s
towertoensurethattherearenoleaksinthelineor
fittings
Moisture Proofing Coax Connectors
and Fittlngs
Extreme care must be exercised with coaxial
cable before and afier connectors have been installed
to erlsure that moisture does not enter the line. Foam
dielearic line can take on moisture absorption which
is difiicult to detect and remedy. Therefore, keep the
line dry while in storage with ends tiditly capped.
Coaxial splices, connectors, and fittings, to be located
outside should be made mechanically tight then
coated with a weather-proofing material over at least
two layers of vinyl plastic electrical tape. Moisture
problems in antenna systems are usually traced back
to connectors which have NOT been properly taped.
The Marti K-l Grounding and Weatherproofing Kit is
recommended for use in each new antenna
installation.
Location and Grounding of Coaxial
Cable
KeeptheSTLreceivercoain’aleableasfarfiom
thebroadcasttrannnitteranditscoaxialcsbleas
pnssdilc. D0 NOTSTRAP RECEIVER CABLE TO
THE MAINANIENNA GdBLE ATANYPOHVT.
PLACE THE REGIVER ANTENNA COAHAL
CABLE ON THE 09mm SIDE OF HIE
TOWER FROM THE MAIN ANTENNA CABLE.
Maintain maximum separation between these cables at
all points, including the distance fiom tower base to
transmitter budding as well as inside the building
System Groundlng
Itisessentialthattliesuantennasyscemhe
properlygroundedforsat‘etyandproperoperatim
Antenna Installatlon and Adjustment
The polarization of the transmit and receive
antennasoftheS'lLsystcmmustbethe same! This
means that ifthe transmitting antenna is horizontal,
the receiving antenna must also be horizontal. Each
antenna should be attached to the tower to allow for
final adjustment in azimuth heading and vertical tilt.
Afier visual adjustment of the antennas, the
transmitterandreceivercanheusedtcmakethefinal
adjustments of the antennas, With the transmitter
driving one antenna, the receiver antenna is adjusted
for maximum signal (indicated on the receiver) in both
horizontal and vertical directivity CAUTION:
Antemas have a “major“ and several “rm'nor” lobes in
their directivity patterns. A common error is to peak
the antenna on a miner lobe, residting in a signal level
of only a fiction of the major lobe signal This error
can be avoided only by swinging the antenna through
alargeanglesothatalllobesareevalumdandthe
major lobe clearly determined, Alter one antenna is
adjusted, the transmitter and receiver locations are
reversed, to allow adjustment of the other antenna, If
an RF wattmeter is available, each antenna and
transmission line can be checked for VSWR when the
transmitter is supplying power to it. The VSWR
should be less than 1.5 to 1 (1.5:1). D? THE AN-
TENNA SYSTEM NAILS TO GIVE THE PRE-
DICTED SIGNAL STRENGTH LEVEL, THE
FOLLOWING ITEMS SHOULD BE ClmCKED:
2.
3.
4.
Check for oorroct assembly of antennal
Check that antennas have same polarityr
Check orientation ofantennns in both horizontal
and vertical directions
Check VSWR ofboth transmit and receive
antennas. VSWR should be less that 1.5:1.
Check Fresnel zone clearance along radio path
Check fior obmmtions in the path such as trees
and man-made structures. Do NOT depend on
maps or aerial photographs,
CAUTION & WARNING
You CAN BE Imam IE AN ANTENNA COMES
IN CONTACI‘ WITH ELECTRIC POWER LINES
on EXPOSED ELECTRICAL WIRING. FOR
YOUR SAFETY usE EXTREME CAUTION
WI-IEN INSTALLING ANTENNAS. KEEP AWAY
mom POWER LINES.
gfiofPERA TION ,
QUICK START
Simply plug in the STL-20C (there is no power
switch). The float panel meter light will immediately
come on. Within 5 seconds the AFC LOCK LED will
begin flashing indicating that the synthesizer is in the
process of looking on a frequency. Also, if the
TRANSNHT switch is on, the red TRANSMIT LED
will flash in unison with the AFC LOCK LED. During
power up, the synthesizer will always lock on the
frequency it was locked on when the S'I'L-2OC was
last powered up.
Within seconds the synthesizer locks on frequency
and the AFC LOCK LED will immediately stop
flashing and stay on solid green. If the TRANSMIT
switch is on, about 3 seconds later the TRANSMIT
LED will stop flashing and stay on solid red, and then
the STL-ZOC will begin transmitting RF power at
whatever setting the POWER ADIUST pot is at. if
the TRANSM'iT switch is oh" the TRANSMIT LED
will be ofl‘. When the operator tums the TRANSlvflT
switch on, the TRANSMIT LED will come on solid
red and the STL-ZOC will begin transmitting.
if the operator is not sure what frequency the
STL-ZOC will transmit on, before turning on the
TRANSMIT switch, tweak the POWER ADJUST
fully counter-clockwise for minimum power, then turn
the TRANSMIT switch on, Observe the output
frequency on a frequency counter. If the frequency
counter is not detecting a strong enough signal, the
operator may need to slowly tweak the POWER
ADJUST pot for more power.
To change the frequency, refer to the SENDmG
AN INSTRUCTION section.
DETA|LED OPERATION
Transmit-Off Switch
This toggle switch controls the RF output of the
transmitter. The red light above this switch is a visual
indication that the switch is in "TRANSMIT"
position. The audio circuits, the 13 5 volt regulated
power supply and the meter illumination lamps remain
on when the TRANSMJT switch is "OFF".
Test Meter
The TEST METER, with its selector switch,
allows monitoring of six important parameters within
the transmitter as follows:
1. When switched to “FORWARD POWER", the
meter indicates the RF power output of the STL~
20C transmitter. The maximum power is 20
Watts (ls Watts nominal).
2, When switched to "REFLECTED POWER”, the
TEST METER indicates the amount of power
returning on the coaxial line from the antenna. This is
useful in determining the VSWR (Voltage Standing
Wave Ratio) for the antenna system, The lower the
VSWR for a given forward power, the better. Most
antennas guarantee a VSWR of less than 15 to l.
The table below gives VSWR for Various reflected
powers:
Forward Reflected
10 Wnfls (890-960 MHz)
10 Watts (890-960 MHz)
10 Watts (890-960 MHz)
10 Watts (890-960 MHz)
10 Watts (890-960 MHz)
0.4 watts
0.5 watts
15 watts (140480 MHz)
15 watts (140-480 MHz)
IS watts (140-480 MHz)
15 watts (140-480 MHz)
15 watts (140-480 MHz)
0.4 watts 1.40
0.7 watts 1.55
3. “SUB LEVEL" » Indicates subcarrier injection. 0
VU is approximately 10% injection. Subcam'er
voltage at 11 or B is approximately 0.5 Volt RMS
(1.5 v, P-P) for 10%,
4. "+13 VOLT SUPPLY" - Indicates regulated
voltage supply operation. +l.5 VU is
approximately 13.5 VDC.
5, “PA. CURRENT" - The current of the final
amplifier and its driver is calibrated to read "0
VU" on the meter correSponding to a maximum
rated power output.
LED Indicators (front panel)
1. AFC LOCK light — A solid green LED light is
illuminated when the synthesizer VCO is locked
on the desired output frequency. If unlocked, or
in the process of being locked the AFC LOCK
LED flashes green. RF power output is inhibited
until AFC Lock is achieved. Initial power-up of
the transmitter may require several seconds to
achieve AFC Lock.
2, TRANSMIT light v A solid red LED light is
illuminated when the STL transmitter is
transmitting output power. If the TRANSMJT
switch is on and the STL transmitter is not
transmitting output power due to AFC unlock,
frequency change or very high temperature fault,
the TRANSMIT LED flashes red, If the
TRANSMIT switch is off the TRANSMIT LED
will also be off,
3. HIGH VSWR light — When the STL is operating
at a detected VSWR of less than 2, the HIGH
VSWR LED is off and the transmitter can
operate up to a maximum power of 20 Watts. If
the STL internal controller detects a VSWR
measured between 2 and 4, the HIGH VSWR
LED flashes red at a slow rate of approximately
once a second. When this happens, the controller
will limit the output power to 10 Watts. If the
STL internal controller detects a measured
VSWR of greater than 4, the HIGH VSWR LED
flashes red at a fast rate of approximately twice a
second. When this happens, the controller will
limit the output power to 5 Watts.
4. HIGH TEMP light — When the STL’s PA is
operating at a temperature of less than 65 degrees
C the HIGH TEMP LED will be off. When the
internal controller detects a PA temperature
between 65 and 80 derees C, the HIGH TEMP
LED will flash red at a slow rate of
approximately once a second, When the internal
controller detects a PA temperature of greater
than 80 degrees C, the HIGH TEMP LED will
flash red at a fast rate of approximately twice a
second. When this happens the controller will
shut down the output power. The output power
will remain shut down and the HIGH TEMP
lROADCAST ELECTRONICS
FCC ID : DDE—STL-2OW-9SOS
JOB # : 250Ul
EXHIBIT # ;
G6
ll
LED will flash red twice a second until the
temperature falls to less than 55 degrees C, upon
which the STL will resume transmitting to it
previously set power.
5, MODE-COMPOSITE/MONO - Amber colored
LED lights indicate the selected mode of
operation. Jumper plug "JP4" on 800-285 Audio
Processing Board turns on the MONO light;
"JP3".turns on the COMPOSITE light.
Peak Modulation Meter
A “peak hold" twelve segment bar graph
display is included on the STL<20C transmitter for
setting and monitoring peak STL modulation
(composite or mono mode). The five highest LED’s
(100% to 250%) have a “peak hold” feature which
will display an instantaneous peak value for one
second. This is a valuable feature when dealing with
pro-emphasized program audio, The procedure for
setting peak modulation is to adjust the (mono or
composite) input level into the STL-20C until the
100% bar is flashing on audio peaks, The llO% thm
250% bars indicate over-modulation and require a
reduction in input level to obtain a 100% peak
indication,
Pre-Emphasis Selection
(Mono Operation only)
Two progammable Jumper plugs JPS and H6, on
800-235 Audm Processing Board, enable the user to
select 0 us, 25 us, 50 us, or 75 us pre—emphasis
characteristics. The selection of one of these options
in the transmitter requires a corresponding selection
of IPQ and J'PlO on the receiver (R—ISC) Audio
Processing Board, 800-294, Refer to Drawing 800-
285 and Drawing 800-294 for the location of these
plugs. The plugs as shown in the diagrams, are
positioned for 75 us at the factory. 75 ps pre-
emphasis and de-emphasis produces the best threshold
noise performance in an FM system.
It does, however, present problems in modulation
control. Some users, therefore, may wish to use 50
us, 25 us, or flat processing. AM stations will find flat
processing desirable since the STL can be treated as a
pair of wires in proof-of-perfonnance tests without
possible overmodulation of the link at high audio
frequencies. With 75 us pre—emphasis, audio input
levels to the transmitter should be reduced 20 dB
below 100% modulation when running frequency
response tests to prevent overmodulation at the higher
audio frequencies. With a full-quieting RF signal into
the receiver, flat pre-emphasis will produce a system
signal-to-noise ratio approximately 6 dB less than 75
as pre—emphasis. Received signal levels less than fixll
quieting may produce a difi'erence of as much as 13
dB between flat and 75 us pre-emphasis.
Power Adjust Pot
Rotating the POWER ADJUST pot clockwise will
increase the output power. Rotating it counter-
clockwise will decrease the output power.
Frequency Measurement
The RF output fi'equency of this transmitter should
be measured and adjusted as ofien as necessary to
insure on-frequeney operation and to comply with
regulations. This procedure is covered in the TUNE
UP and ADJUSTMENT section.
'LOADCAST ELECTRONICS
FCC ID : DDE-STL-ZOW—9SOS
JOB # : 250Ul
EXHIBIT a : (g C,
RF EXPOSURE WARNING
This studio to transmitter ling unit (STL) contains a radio frequency (RF) transmitter. During
normal operation it sends out radio frequency (RF) signals. In August 1996, the Federal
Communications Commission (FCC) adopted RF exposure guidelines with safety levels for
Wireless devices.
CAUTION: To maintain compliance with the FCC‘s RP exposure guidelines, the antenna(s)
used for this transmitter must be installed (0 provide a separation distance of at least 2 meters from
all persons during normal operation and must not be co-located or operating in conjunction with
any other antenna or transmitter.
Unauthorized antennas, modifications, or attachments could damage the transmitter and may
violate FCC regulations,
BROADCAST ELECTRONICS
FCC ID : DDE~STL~20W-9SOS
JOB : 250Ul
EXHlBlT# : 7D
The STL-ZOC transmitter, R-15C receiver with the
associated antenna system can be tested and com-
pared with fiactory test data included in this manual.
The following procedures should be followed in order
to obtain reliable and accurate results.
Before audio tests or subcarrier tests are begun
check the receiver “SIG. LEVEL” METER for
required minimum signal, A conversion from W to
microvolts is given under OPERAflON in the 11-15
rweiver nwntul. For a 950 MHz. system using 50
KHz FM deviation, typical noise levels in Composite
Mode are:
10 uv for 50 dB SIN ratio
63 pv for 60 dB SIN ratio
80 uv for ultimate SIN ratio
(Demodulated lett or right channel de-em-
phasized and low-pass filtered)
For the above system with 7.0% whom-is:
injection. the following noise level on the suboarrier
(Mani SCG-IO - SUD-10 System) was measured:
(no modulation main or sub)
for 40 dB Subcaniel' SIN ratio
for 47 dB Subcan'ler SIN ratio
for 50 dB Subcarrier SIN ratio
for ultimate Suboan'ier SIN ratio
10 pv
20 pv
30 pv
150 pv
WrthultimateS/Nmio,maintosubcrosstalk
shouldbe-40 to 45 dB (usinngrti SCG-lo - SCD-
10 Suburrier System),
NOISE
(monophonic mode)
Noise nwasuremarts should be made first, since
high noise levels will influence distortion readings.
Also ground loops in the audio oscillator to
transmitter connections and distortion analyzer to
receiver connections must be resolved before testing
begins. The influence of high RF fields upon the test
equipment must be determined and corrected before
accurate measurements can be made. NOTE: NOISE
AND DISTORTION MEASUREMENTS ARE
MADE WITH SUBCARRJER AND REMOTE
CONTROL INPUT SIGNALS MOVED. System
13
signal to noise ratio is determined while
the transmitter 100% at 400 Hz. A level of +8 dBm
across the balanced audio input terminals of TB-I will
produce a reading of 100% modulation on the “PEAK
MODULATION” indicator. Set Receiver “MONO
LEVEL” pot for +10 dBm output into the distortion
analyzer. If the distortion analyzer has a high
impedance input, add a 600 ohm load resistor to
match the receiver, Establish +10 dBm on the audio
voltmeterot’themulyurastherefcreme level for
100% modulation Next, remove the audio signal
from the transmitter input and measure noise level
below reference (100% modulation). This reading
should compare with that published under SYSTEM
SPECIFICATIONS in this manual,
DISTORTION
(monophonic mode)
Harmonic distortion is usually measured at 100%
modulation and at several frequencies. [fore-emphasis
processing is used in the transmitter with cor-
responding de-emphnsis in the receiver, it is normal
for availsble audio level at the receiver to drop with
increasing frequency according to the de—emphasis
curve selected. At 15 KHz, there is suflicient level to
operate most modern distortion analyzers. Distortion
levels should be within specifications. ll’ distortion is
outofspeos,cheoksystemnoise,ohedcfortest
equipment ground loops, RH, and transmit-
ter/receiver operating fl'equetwy. If either unit is off
fi'equency, the FM modulation sidebands are not
cornered within the [F filter bandpass, which can
cause audio distortion
FREQUENCY RESPONSE
(monophonic mode)
If the STL-ZOC Symm is switched to flat
processing, fi-equency response can be measured as if
thesignalwerebeingsernoverstraightwires.lt'pre-
emphasis processing is used (especially 75 pa)
allowance must be made in the transmitter audio
input level to prevent over-modulation at test
frequencies above 400 Hz. The simplest and fastest
method is to set the transmitter audio input level for
100% modulation at 400 Hz, than attenuate this level
20 (15. Set receiver output level to -10 dBm as the
reference, then sweep the audio band for response,
Response should be within the limits listed in
SYSTEM SPECIFICATIONS
14
COMPOSITE (STEREO) SEP-
ARATION. NOISE. DISTORTION
AND FREQUENCY RESPONSE.
(composite mode)
This procedure consists of feeding a stereo
enooder (generator) capable of more than 60 dB
separation (50 Hz - 15 KHz) into the composite input
of the STL-ZOC transmitter and connecting a stereo
decoder (monitor) to the composite ouqmt of the R-
15C receivers The actunltestproeeduremayvarywith
difietent decoders (monitors) Therefore the proce-
dure presented in the decoder (monitor) instruction
manual should be followed
SENDING AN INSTRUCTION
Refer to drawing 597-6020—2.
This section outlines how to send an instruction to the T/R SYNTHESIZEL The controls for sending an instruction
all reside on the SYNTHESIZER CONTROL BOARD (800-377). These controls consist of three S-pin dip switches
labeled 51, S2, and $3, and one pushbutton switch labeled S4, For the STL-ZOC the only instructions that are needed are
as ibllows:
Frequency Change
Forward Power Calibration
Reverse Power Calibration
Normal Operation
Power Control - Max
StoreRanowerIntoCal?osifion#(where#representsnnumb«fi'om0w8)
P‘MfiPNr‘
Following are EM steps for sending an instruction:
1. Setthe dip switches ofSl, S2, and S3 according to the instruction fonnnt. A“l” indicatesthntthe dip switch is
phoed in the OFF position. A “0’ indiutes that the dip switch is placed in the ON position. An “x” indicates
thatitdoesnotmatterwhatposifiontheswitchisin.
Zr Pushtbe Mpuflbumnsfitdtdownmdflwnrelfise.
INSTRUCTIDNFDHMAT
Wm
Refer to the FREQUENCY DIP-SWITCH SETTINGS section.
EQEMISI 291m cm flm'fln'
SI 82 53
87654321 87654321 87654321
lDODOle xxxxxxxx 00001xxx
MW
81 S2 83
87654321 87654321 87654321
1000001x xxxxxxxx 00010xxx
MM
51 82 83
87654321 87654321 87654321
1000001x xxxxxxxx 01000xxx
1=
5] 52 53
87654321 87654321 87654321
1011000x Oxxxxxxx xlllllll
94
43
00
—a
ow
“a
—m
21
1x
u“
Ofl .
ua '
—u
0&2
cu
an
x—
”E
uh
ow
ufi
—m
0&—
on
#N
xn
“E
—a
04
_a
_u
oAn
on
_N
an
”E
oAa
an
oq
_a
—m
ow
—N
9&2 o‘E 0&9
x-
egg
fi
21
xxxx0000
87654321
xxxxoll!
87654321
xxxx1000
87654321
xxxxxxxx
87654321
xxxxxxxx
87654321
xxxxxxxx
fi
87654321
xxxxxxxx
fi
87654321
xxxxxxxx
87654321
xxxxxxxx
87654321
xxxxxxxx
87654321
xxxxxxxx
87654321
xxxxxxxx

---

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.3
Linearized                      : No
Modify Date                     : 2001:11:01 16:02:19-05:00
Create Date                     : 2001:10:31 16:19:24-05:00
Creator                         : Acrobat 4.05 Scan Plug-in for Windows
Producer                        : Acrobat 4.05 Scan Plug-in for Windows
Page Count                      : 16

EXIF Metadata provided by EXIF.tools