Broadcast Electronics Marti Electronics SR-30 User manual

Broadcast Electronics
4100 North 24th Street, Quincy, Illinois 62305 USA • Phone [phone] • Fax [phone] • www.bdcast.com • [email protected]
SR–30 RPU RECEIVER
SR–40A RPU RECEIVER
Marti
Electronics
SR-30
SR-40A
RPU Receiver
597-8104 rev B
March 24, 2011

Marti Electronics
SR-30
SR-40A
RPU Receiver
©2011 Broadcast Electronics. All rights reserved.
The information in this publication is subject to improvement and change without notice. Although
every effort is made to ensure the accuracy of the information in this manual, Broadcast Electronics
accepts no responsibility for any errors or omissions. Broadcast Electronics reserves the right to
modify and improve the design and specifications of the equipment in this manual without notice.
Any modifications shall not adversely affect performance of the equipment so modified.
Proprietary Notice
This document contains proprietary data of Broadcast Electronics. No part of this publication may be
reproduced, transmitted, transcribed, stored in a retrieval system, translated into any other language
in any form or by any means, electronic or mechanical, including photocopying or recording, for any
purpose, without the express written permission of Broadcast Electronics.
Trademarks
Broadcast Electronics and the BE logo are registered trademarks of Broadcast Electronics.
Marti Electronics and the Marti logo are registered trademarks of Broadcast Electronics.
All other trademarks are property of their respective owners.
No part of this manual may be reproduced, 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 of Marti Electronics.
Copyright
Copyright laws protect artwork depicting circuitry in this manual.
Information in this manual is subject to change 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 described
herein at any time.
This product could include technical inaccuracies or typographical errors.

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©2011 Broadcast Electronics
Marti Electronics
Product Warranty (One-Year Limited)
Broadcast Electronics (BE) hereby warrants all new Marti Electronics branded products, including STL
systems, manufactured by BE, against any defects in material or workmanship at the time of delivery
thereof, or that develop under normal use within a period of one (1) year, from the date of
shipment.
BE reserves the right to repair equipment under warranty with new or refurbished equipment or
parts. BE’s sole responsibility with respect to any equipment or parts not conforming to this
warranty is to replace or repair such equipment upon the return thereof F.O.B. to BE’s factory in
Quincy, Illinois, U.S.A. In the event of replacement pursuant to the foregoing warranty, only the
unexpired portion of the warranty from the time of the original purchase will remain in effect for any
such replacement.
This warranty shall exclude the following products, component parts and/or assemblies:
(a) Transmitter power output tubes shall only carry the original manufacturer’s or
supplier’s standard warranty in effect on their original shipment date.
(b) All computers, computer peripherals, cables, hard disk drives, etc., shall only carry
the manufacturer’s or supplier’s standard warranty in effect on their original
shipment date.
(c) “Components”, defined as separate and individual parts (e.g. transistors, integrated
circuits, capacitors, resistors, inductors, fans, etc), resold by BE from another
manufacturer or supplier, shall only carry a 90 day warranty, effective the date of
shipment. Any such ‘Components’ being returned for warranty claim must be (1)
returned in their original packaging and (2) must be in new, unused condition.
BE is unable to process or resolve component defects or performance concerns on
components that have been soldered, installed, wired or in any way altered from
new their new condition.
(d) “Resale Equipment”, defined as equipment purchased from another manufacturer
or supplier, then resold by BE, shall only carry such manufacturer’s or supplier’s
standard warranty in effect as of the original shipment date.. All warranty claims
against any and all ‘resale equipment’ sold by BE must be filed directly with the
original equipment manufacturer. BE is unable to process or resolve equipment
defects or performance concerns on products or services not manufactured by BE.
This warranty shall not extend to claims resulting from any acts of God, terrorism, war, defects or
failures caused by Purchaser or user abuse or misuse, operator error, or unauthorized attempts to
repair or alter the equipment in any way.
Under no circumstances shall BE be responsible for indirect, incidental or consequential damages,
including, but not limited to transportation costs, non-authorized repair or service costs, downtime
costs, costs for substituting equipment or loss of anticipated profits or revenue, incurred by
Purchaser, whether based in contract, tort or for negligence or breach of statutory duty or otherwise.
The terms of the foregoing warranty shall be null and void if the equipment has been altered or
repaired without specific written authorization from BE, or if not installed according to BE’s
instruction manuals, including, but not limited to, the absence of proper grounding, surge (TVSS)
protection on the AC circuit panel or proper lightning protection/grounding on all output circuits, or
if equipment is operated under environmental conditions or circumstances other than those
specifically described in BE’s product literature or instruction manual which accompany the

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©2011 Broadcast Electronics
equipment. The warranty shall be voided if the product or subassembly is equipped with a tamper
seal and that tamper seal is broken. BE shall not be liable for any expense of any nature whatsoever
incurred by the original user without prior written consent of BE. The warranty provided herein shall
terminate at the end of the period set forth above. This warranty extends only to the original
Purchaser and is not transferable. There are no third party beneficiaries of any of the provisions of
this warranty. If the equipment is described as “used” equipment, it is sold as is and where is and no
warranty applies unless authorized in writing.
EXCEPT AS SET FORTH HEREIN, AS TO TITLE AND AS SPECIFICALLY REQUIRED BY LAW, THERE ARE
NO OTHER WARRANTIES, OR ANY AFFIRMATIONS OF FACT OR PROMISES BY BE, WITH REFERENCE
TO THE EQUIPMENT, OR TO MERCHANTABILITY, FITNESS FOR A PARTICULAR APPLICATION, SIGNAL
COVERAGE, INFRINGEMENT, OR OTHERWISE, WHICH EXTEND BEYOND THE DESCRIPTION OF THE
EQUIPMENT ON THE FACE HEREOF.

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©2011 Broadcast Electronics
IMPORTANT INFORMATION
EQUIPMENT LOST OR DAMAGED IN TRANSIT -
When delivering the equipment to you, the truck driver or carrier’s agent will present a receipt for
your signature. Do not sign it until you have:
1) Inspected the containers for visible signs of damage and 2) Counted the containers and compared
with the amount shown on the shipping papers. If a shortage or evidence of damage is noted, insist
that notation to that effect be made on the shipping papers before you sign them.
Further, after receiving the equipment, unpack it and inspect thoroughly for concealed damage. If
concealed damage is discovered, immediately notify the carrier, confirming the notification in
writing, and secure an inspection report. This item should be unpacked and inspected for damage
WITHIN 15 DAYS after receipt. Claims for loss or damage will not be honored without proper
notification of inspection by the carrier.
RF PRODUCT TECHNICAL ASSISTANCE, REPAIR SERVICE, PARTS -
Technical assistance is available from Broadcast Electronics by letter, prepaid telephone or E-mail.
Equipment requiring repair or overhaul should be sent by common carrier, prepaid, insured, and well
protected. If proper shipping materials are not available, contact the RF Technical Services
Department for a shipping container. Do not mail the equipment. We can assume no liability for
inbound damage, and necessary repairs become the obligation of the shipper. Prior arrangement is
necessary. Contact the RF Technical Services Department for a Return Authorization.
Emergency and warranty replacement parts may be ordered from the following address. Be sure to
include the equipment model number, serial number, part description, and part number. Non-
emergency replacement parts may be ordered directly from the Broadcast Electronics stock room at
the number shown below.
RF TECHNICAL SERVICES -
Telephone: [phone]
E-Mail: [email protected]
Fax: [phone]
FACILITY CONTACTS -
Broadcast Electronics, - Quincy Facility
4100 N. 24th St. P.O. BOX 3606
Quincy, Illinois 62305
Telephone: [phone]
Fax: [phone]
General E-Mail: [email protected]
Web Site: www.bdcast.com
PARTS -
Telephone: [phone]
E-Mail: [email protected]

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©2011 Broadcast Electronics
RETURN, REPAIR, AND EXCHANGES -
Do not return any merchandise without our written approval and Return Authorization. We will
provide special shipping instructions and a code number that will assure proper handling and
prompt issuance of credit. Please furnish complete details as to circumstances and reasons when
requesting return of merchandise. All returned merchandise must be sent freight prepaid and
properly insured by the customer.
MODIFICATIONS -
Broadcast Electronics, reserves the right to modify the design and specifications of the equipment in
this manual without notice. Any modifications shall not adversely affect performance of the
equipment so modified.

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©2011 Broadcast Electronics
SAFETY PRECAUTIONS
PLEASE READ AND OBSERVE ALL SAFETY PRECAUTIONS!!
ALL PERSONS WHO WORK WITH OR ARE EXPOSED TO POWER TUBES, POWER
TRANSISTORS, OR EQUIPMENT WHICH UTILIZES SUCH DEVICES MUST TAKE PRECAUTIONS
TO PROTECT THEMSELVES AGAINST POSSIBLE SERIOUS BODILY INJURY. EXERCISE
EXTREME CARE AROUND SUCH PRODUCTS. UNINFORMED OR CARELESS OPERATION OF
THESE DEVICES CAN RESULT IN POOR PERFORMANCE, DAMAGE TO THE DEVICE OR
PROPERTY, SERIOUS BODILY INJURY, AND POSSIBLY DEATH.
DANGEROUS HAZARDS EXIST IN THE OPERATION OF POWER TUBES AND
POWER TRANSISTORS -
The operation of power tubes and power transistors involves one or more of the following hazards,
any one of which, in the absence of safe operating practices and precautions, could result in serious
harm to personnel.
A. HIGH VOLTAGE - Normal operating voltages can be deadly. Additional information
follows.
B. RF RADIATION - Exposure to RF radiation may cause serious bodily injury possibly
resulting in Blindness or death. Cardiac pacemakers may be affected. Additional
information follows.
C. HOT SURFACES - Surfaces of air-cooled radiators and other parts of tubes can reach
temperatures of several hundred degrees centigrade and cause serious burns if touched.
Additional information follows.
D. RF BURNS - Circuit boards with RF power transistors contain high RF potentials. Do not
operate an RF power module with the cover removed.

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©2011 Broadcast Electronics
HIGH VOLTAGE –
Many power circuits operate at voltages high enough to kill through electrocution. Personnel should
always break the primary AC Power when accessing the inside of the transmitter.
RADIO FREQUENCY RADIATION -
Exposure of personnel to RF radiation should be minimized, personnel should not be permitted in the
vicinity of open energized RF generating circuits, or RF transmission systems (waveguides, cables,
connectors, etc.), or energized antennas. It is generally accepted that exposure to “high levels” of
radiation can result in severe bodily injury including blindness. Cardiac pacemakers may be affected.
The effect of prolonged exposure to “low level” RF radiation continues to be a subject of
investigation and controversy. It is generally agreed that prolonged exposure of personnel to RF
radiation should be limited to an absolute minimum. It is also generally agreed that exposure should
be reduced in working areas where personnel heat load is above normal. A 10 mW/cm2per one
tenth hour average level has been adopted by several U.S. Government agencies including the
Occupational Safety and Health Administration (OSHA) as the standard protection guide for
employee work environments. An even stricter standard is recommended by the American National
Standards Institute which recommends a 1.0 mW/cm2 per one tenth hour average level exposure
between 30 Hz and 300 MHz as the standard employee protection guide (ANSI C95.1-1982).
RF energy must be contained properly by shielding and transmission lines. All input and output RF
connections, such as cables, flanges and gaskets must be RF leak proof. Never operate a power tube
without a properly matched RF energy absorbing load attached. Never look into or expose any part
of the body to an antenna or open RF generating tube or circuit or RF transmission system while
energized. Monitor the tube and RF system for RF radiation leakage at regular intervals and after
servicing.
HOT SURFACES –
The power components in the transmitter are cooled by forced-air and natural convection. When
handling any components of the transmitter after it has been in operation, caution must always be
taken to ensure that the component is cool enough to handle without injury.

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©2011 Broadcast Electronics
Table of Contents


1Introduction............................................................................................1
1.1SPECIFICATIONS & ORDERING.................................................................. 1
1.2Available OPTIONS for the SR-30/SR-40A Receivers................................... 3
1.3UNPACKING & INSPECTING...................................................................... 3
2Installation ..............................................................................................4
2.1STANDARD CONNECTIONS ...................................................................... 4
2.2Mobile Repeater Connections .................................................................. 7
3ANTENNAS...............................................................................................8
3.1BASE STATION ANTENNA INSTALLATION CHECKLIST................................ 9
4OPERATION ............................................................................................11
4.1CONTROLS AND INDICATORS ................................................................ 11
4.2INITIAL START–UP AND OPERATION....................................................... 15
5THEORYOF OPERATION ..........................................................................17
5.1Converter, 913–2132–150/–240/–330/–450/–950.................................. 17
5.2IF Bandpass Filter, 800–207 ................................................................... 17
5.3IF Amplifier/Detector, 800–208 .............................................................. 17
5.4Audio Amplifier, 800–228 ..................................................................... 17
5.5Tone Decoder, 800–229 ........................................................................ 17
5.6Input/Output Filter, 800–193AD ............................................................ 19
5.7Front Panel Circuit Board Assembly, 953–2130–001/–002...................... 19
6TEST EQUIPMENT ................................................................................... 20
7TOOLS FOR ALIGNMENT ......................................................................... 20
8TUNE–UPAND ADJUSTMENTS ................................................................ 21
8.1IF Amplifier/Detector Circuit Board Adjustments ..................................... 21
8.2Decode Board Circuit Board Adjustments ............................................... 21
8.3POWER SUPPLY/METER CALIBRATION .................................................... 22
9SR 30 BILL OF MATERIAL ....................................................................... 23
10SR 40A BILL OF MATERIAL..................................................................... 33

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11Wideband Converters and Filters ......................................................... 43
12SCHEMATICS .........................................................................................68


1
SR-30 / SR-40A RPU Receivers
1Introduction
The Marti SRPT-30 and SRPT-40A Transmitters with companion SR-30/SR-40A Receivers, form a high quality
FM, synthesized, point-to-point, line of sight, radio communications link for remote broadcast applications.
The SR-30 receiver is a dual channel unit that can be programmed on any 2 frequencies within a 50 MHz
band. The SR-40A receiver is frequency agile within a 50 MHz band. Complex systems can be built from
basic SRPT-30/SRPT-40A transmitters and SR-30/SR-40A receivers having multiple relay (repeaters), bi-
directional (full duplex), and automatic switching standby features. Each SR-30 and SR-40A RPU receiver is
offered in a wide range of band models. Refer to the SPECIFCATIONS & ORDERING section for a listing of
available frequency ranges.
The SR-30/SR-40A receivers operate from: 1) an 85 to 264 VAC, 47 to 63 Hz or 2) a +10 to +14 VDC source.
A meter and selector switch is provided for monitoring, signal level, decode level, power supply voltage, and
the program output level. A front panel attenuation switch allows the input level to be adjusted to minimize
any IMD products. Additional front panel controls include: 1) a program output level control, 2) a squelch
control, 3) an F1/F2 switch on SR-30 models, and 4) an execute switch on SR-40A models. The SR-30/SR-40A
front panel indicators include: 1) MAX signal, 2) ATT signal, 3) UNSQUELCHED, 4) POWER, 5) AFC LOCK, and
6) F1/F2 on SR-30 models.
SR-30/SR-40A Features:
•Mechanical design – Allows each unit to be portable or rack mounted
•Wideband operation - 50 MHz
•SR-30 Models – Two channel operation within a 50 MHz band
•SR-40A Models – Frequency agile within a 50 MHz band
•Switching power supply operates on any AC voltage from 85V to264V, 47 to 63 Hz
•External +10 to +14 VDC operation
•Frequency synthesized dual stage RF converter module with Automatic Frequency
Control (AFC)
•Front panel signal attenuation control – used to minimize IMD products
•Front panel squelch control
•Front panel headphone control and receptacle
•A microcontroller programmed to perform the following functions:
•Front-panel switch and indicator control
•AFC lock control
•Metering control
•Auto recovery from loss of ac/dc power
•Subaudible tone decoder available for signaling, automation control, or automatic
repeater
•Squelch relay with contacts available for external switching
1.1 SPECIFICATIONS & ORDERING
Frequency Bands: See ORDERING INFORMATION below.
Type of technology to
produce operating
frequency:
Phase-locked loop; synthesized
Frequency Agility and
Accuracy
Frequency programmable in 100 Hz increments with
an accuracy (1) ± ?%

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©2011 Broadcast Electronics
Operating Temp.
Range:
-10ºC to +50ºC
Frequency Stability
(over operating
temperature range):
0.0001%
Signal–to–Noise @ 100
uV Input:
36 kHz BW @ 5.4 kHz Dev
25 kHz BW @ 3.6 kHz Dev
10 kHz BW @ 1.2 kHz Dev
Greater than 57 dB.
Greater than 53 dB.
Greater than 44 dB.
Frequency Response: ± 1.5 dB of the specified bandwidth
Distortion: 2% or less of the specified bandwidth
Spurious Response: -90 dB
RF Input Impedance: 50 ohms
RF Connector: Type N-Female
Output Level: -10 to +11 dBm
Output Impedance: Balanced, 600 Ohms, 15-pin D-Type connector
Sensitivity: 0.5 microvolts for 20 dB signal-to-noise
2 microvolts for 30 dB signal-to-noise
4 microvolts for 40 dB signal-to-noise
100 microvolts for maximum signal–to–noise,
typically 57 dB or greater.
Metering/Indicators: Illuminated meter indicates: 1) signal level, 2) decode
level, 3) power supply level, and 4) mono program
output level. LEDs – MAX Signal, ATT Signal,
UNSQUELCHED, POWER supply, AFC LOCK, and F1/F2
on SR–30 Models.
Front Panel Controls: SIGNAL ATTENUATION, MONO PROGRAM OUTPUT
LEVEL, SQUELCH LEVEL, meter selection control,
HEADPHONE level control.
Power Requirements: 85 to 264 VAC, 47 to 63 Hz
External DC operation on - +10 to +14 VDC
Approximate AC
Current Requirements:
1.5 Amps
Accessory Connector: 15-pin D connector
Weight: Net 67 pounds. (3.0 kilograms).
Dimensions: 3.5 in. high x 12 in. wide x 15 in. deep.
(8.9 cm. high x 30.5 cm. wide x 38.1 cm. deep.)
Regulatory: FCC, DOC

3
1.1.1 ORDERING INFORMATION
MARTI PART # Description
SR30
–
150
–
025 SR–30 RPU Receiver, 135 to 182 MHz, 2 Channel, 25 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
150
–
036 SR–30 RPU Receiver, 135 to 182 MHz, 2 Channel, 36 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
240
–
025 SR–30 RPU Receiver, 215 to 265 MHz, 2 Channel, 25 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
240
–
036 SR–30 RPU Receiver, 215 to 265 MHz, 2 Channel, 36 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
3
30
–
036 SR–30 RPU Receiver, 300 To 350 MHz, 2 Channel, 36 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
450
–
020 SR–30 RPU Receiver, 430 To 480 MHz, 2 Channel, 20 KHz Receive Bandwidth (TSL),
110/220VAC 50/60 Hz Operation.
SR30
–
450
–
025 SR–30 RPU Receiver, 430 To 480 MHz, 2 Channel, 25 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
450
–
036 SR–30 RPU Receiver, 430 To 480 MHz, 2 Channel, 36 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR30
–
450
–
050 SR–30 RPU Receiver, 430 To 480 MHz, 2 Channel, 50 KHz Receive Bandwidth, 110/220VAC
50/60 Hz Operation.
SR40A
–
150
–
025 SR–40A RPU Receiver, 135 to 182 MHz, Frequency Agile, 25 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
150
–
036 SR–40A RPU Receiver, 135 to 182 MHz, Frequency Agile, 36 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
240
–
025 SR–40A RPU Receiver, 215 to 265 MHz, Frequency Agile, 25 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
240
–
036 SR–40A RPU Receiver, 215 to 265 MHz, Frequency Agile, 36 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
3
30
–
036 SR–40A RPU Receiver, 300 To 350 MHz, Frequency Agile, 36 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
450
–
025 SR–40A RPU Receiver, 430 To 480 MHz, Frequency Agile, 25 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
450
–
036 SR–40A RPU Receiver, 430 To 480 MHz, Frequency Agile, 36 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
SR40A
–
450
–
050 SR–40A RPU Receiver, 430 To 480 MHz, Frequency Agile, 50 KHz Receive Bandwidth,
110/220VAC 50/60 Hz Operation.
1.2 Available OPTIONS for the SR-30/SR-40A Receivers
Marti No. Description
700-250-13 Kit, Rack Mounting
1.3 UNPACKING & INSPECTING
This equipment was factory tested, inspected, packed, and delivered to the carrier with utmost care. Do not
accept shipment from carrier, which shows damage or shortage until the carrier's agent endorses a statement
of the irregularity on the face of the carrier's receipt. Without documentary evidence, a claim cannot be filed.

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©2011 Broadcast Electronics
Unpack equipment immediately up-on receipt and thoroughly inspect for concealed damage. If damage is
discovered, stop further unpacking and request immediate inspection by local agent of carrier. A written
report of the agent's findings, with his signature is necessary to support claim. Check your shipment against
the shipping papers for possible shortage. Do not discard any packing material until all items are accounted
for. Small items are often thrown away with packing material.
Packing material should be retained until equipment testing is completed. Any equipment returned to the
factory should be packed in original cartons, insured, and pre-paid.
2Installation
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 has 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.
2.1 STANDARD CONNECTIONS
1. Connect the receiving antenna coax to the ANTENNA TYPE N port on the rear–panel using a
type–N male connector. A short flexible jumper, 20 inches maximum, may be used between the
ANTENNA port and the Heliax. Marti Part No. 585–017 Double–Shielded, Low–Loss RG–214/U
jumper is recommended.
2. Balanced program audio output is located at accessory connector J4–4 and J4–5 (refer to Figure 1).
The output level can be adjusted from –10 to +11 dBm. Refer to the accessory kit and locate the
15–Pin D–Type mating connector. Connect shielded audio cable to J4–4 and J4–5. If unbalanced
audio is desired, connect the cable between J4–4 (signal) and J4–1 (ground). Once the audio cable
is installed, connect the mating connector to the J4 receptacle on the rear–panel.
CAUTION
IF DC OPERATION IS REQUIRED, DO NOT APPLY MORE THAN +14V
TO THE UNIT.

5
3. Ensure the receiver rear–panel ON/OFF switch is OFF. Connect the rear–panel AC line receptacle to an
85 to 264V, 47 to 63 Hz AC power source. USE ONLY A 3–PRONG GROUNDED OUTLET RECEPTACLE FOR
SAFETY. The unit can also be operated from a +10V to +14V external dc supply. If DC operation is
required, refer to Figure 1 and connect: 1) the positive wire to J4–7 and 2) ground to J4–8.
4. The receiver is equipped with a rear–panel ground terminal. Connect a ground wire between earth
ground and the GND terminal on the receiver rear panel.

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7
2.2 Mobile Repeater Connections
A mobile repeater installation requires one of the following Receiver to Transmitter cables:
-For an RPT–15 Transmitter, use Cable No. 585–037–2 with 4 Amp fuse.
-For an SRPT–30/40A Transmitter, 12–15 VDC operation, use Cable No. 585–139.
-For SRPT–30/40A Transmitter, 15–30 VDC operation, use Cable No. 585–140.
A mobile repeater installation also requires one of the following mobile mounting
brackets:
-For an SR–30/SR–40A receiver, use Mobile Mounting Bracket 700–252.
-For an RPT–15 Transmitter, use Mobile Mounting Bracket 700–252.
-For an RPT–30 Transmitter, use Mobile Mounting Bracket 700–251.
1. Locate the SR–30/SR–40A Receiver and RPT–Series Transmitter in the vehicle and secure with appropriate
mounting brackets.
2. The transmitter and receiver must have individual ground (black wire) connection to bare metal of vehicle
body. Scrape paint from body at point of connection, drill hole and secure ground terminals with metal
screws. Connect red fused wire to the appropriate 12 volt DC source on vehicle.
3. Install vehicle antennas per their instructions.
4. Connect receiving and transmitting antennas. Then connect receiver to transmitter cable listed above
between accessory connector of transmitter and receiver.
5. With system operating, adjust line level input gain pot on transmitter (Input 4 of RPT–30 or AUX pot of
RPT–15) for about 3 dB compression with program material.

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©2011 Broadcast Electronics
3ANTENNAS
CAUTION & WARNING
You can be killed if an antenna comes in contact with electric power lines or
exposed electrical wiring. For your safety use extreme caution when installing
antennas. Keep away from power lines.
Personnel must not be near the antenna when radiating. Locate antenna as far as possible
from people and equipment susceptible to RF radiation. Do not mount antenna directly on
transmitter. Refer to ANSI C95.1 “Limits on Non–Ionizing Radiation.”

9
3.1 BASE STATION ANTENNA INSTALLATION CHECKLIST
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 be a complete step–by–step procedure, simply a listing of some of the
most frequently reported errors in antenna system installation.
3.1.1 Antenna Assembly
Follow the manufacturer’s instructions carefully. If no instructions were included with the antenna, call or
write the antenna manufacturer for instructions. Antennas which have phasing or stacking cables must be
assembled care- fully to avoid phase reversal or signal cancellation.
3.1.2 Transmission Line Connector Assembly
Do not use RG–58U or RG–8U cable for RPU station antennas! They have too much loss at VHF and UHF
frequencies. Follow the instructions furnished by the manufacturer when cutting coaxial cable. Inspect the
cable ends for small metal fragments which can short–circuit the line inside the connector assembly. Check
the line for a short– circuit condition after each connector is installed by using an ohmmeter. Pressurized line
should be checked for several days under pressure before installation on a tower to ensure that there are no
leaks in the line or fittings
3.1.3 Moisture Proofing Coax Connectors and Fittings
Extreme care must be exercised with coaxial cable before and after connectors have been installed to ensure
that moisture does not enter the line. Foam dielectric line can take on moisture by absorption which is
difficult to detect and remedy. Therefore, keep the line dry while in storage with ends tightly 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–1
Grounding and Weatherproofing Kit is recommended for use in each new antenna installation.
3.1.4 Location and Grounding of Coaxial Cable
Keep the RPU receiver coaxial cable as far from the broadcast transmitter and its coaxial cable as possible. DO
NOT STRAP RECEIVER CABLE TO THE MAIN ANTENNA CABLE AT ANY POINT. PLACE THE RECEIVER ANTENNA
COAXIAL CABLE ON THE OPPOSITE SIDE OF THE TOWER FROM THE MAIN ANTENNA CABLE. Maintain
maximum separation between these cables at all points, including the distance from tower base to
transmitter building as well as inside the building.
3.1.5 System Grounding
It is essential that the RPU antenna system be properly grounded for safety and proper operation.
3.1.6 Antenna Installation and Adjustment
The polarization of the transmit and receive antennas of the RPU system must be the same! This means that if
the transmitting antenna is vertical, the receiving antenna must also be vertical. Each antenna should be
attached to the tower using the proper side mount or top mount hardware. 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). IF THE ANTENNA SYSTEM FAILS TO GIVE THE PREDICTED
SIGNAL STRENGTH LEVEL, THE FOLLOWING ITEMS SHOULD BE CHECKED:
1. Check for correct assembly of antenna.
2. Check that antennas have same polarity.

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3. Check VSWR of both transmit and receive antennas. VSWR should be less than 1.5:1.
4. Check for obstructions in the path such as trees and man–made structures. The base antenna must be
high enough to provide a line–of–sight path to the remote transmitting antenna.