FCC ID: DDE-GTX900 STL Transmitter

 

Broadcast Electronics

4100 North 24th Street, Quincy, Illinois 62305 USA • Phone (217) 224-9600 • Fax (217) 224-9607 • www.bdcast.com • bdcast@bdcast.com

Marti GTX / GRX

BROADCAST STL

USER AND MAINTENANCE MANUAL

Revision 1.3

Mar 29, 2021

GTX / GRX STL TRANSMITTER & RECIEVER

Technical Manual

©2021 Broadcast Electronics all rights reserved.

i

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.

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 Broadcast Electronics.

Broadcast Electronics may make improvements and/or changes in this manual or in the product

described herein at any time.

Broadcast Electronics Product Warranty (One-Year Limited)

Broadcast Electronics hereby warrants the Marti GTX & GRX products manufactured by Broadcast

Electronics 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.

Broadcast Electronics reserves the right to repair equipment under warranty with new or

refurbished equipment or parts. Broadcast Electronics’ 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 Broadcast Electronics’ 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 manufacturers’ or

suppliers’ standard warranty in effect on their original shipment date.

©2021 Broadcast Electronics

ii

(b)

(c)

(d)

All computers, computer peripherals, cables, hard disk drives, etc., shall only carry

the manufacturers’ or suppliers’ standard warranty in effect on their original

shipment date.

“Components”, defined as separate and individual parts (e.g. transistors, integrated

circuits, capacitors, resistors, inductors, fans, etc.), resold by Broadcast Electronics

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. Broadcast Electronics 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 their new condition.

“Resale Equipment”, defined as equipment purchased from another manufacturer or

supplier, then resold by Broadcast Electronics, shall only carry such manufacturer’s

or suppliers’ standard warranty in effect as of the original shipment date. All

warranty claims against any and all “resale equipment” sold by Broadcast

Electronics must be filed directly with the original equipment manufacturer.

Broadcast Electronics is unable to process or resolve equipment defects or

performance concerns on products or services not manufactured by Broadcast

Electronics.

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 Broadcast Electronics 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 Broadcast

Electronics, or if not installed according to Broadcast Electronics’ 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 Broadcast

warranty shall be voided if the product or subassembly is equipped with a tamper seal and

Electronics’ product literature or instruction manual which accompany the equipment.

that tamper seal is broken.

The

Broadcast Electronics shall not be liable for any expense of any nature

whatsoever incurred 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 BROADCAST

ELECTRONICS, 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.

©2021 Broadcast Electronics

IMPORTANT INFORMATION

iii

EQUIPMENT LOST OR DAMAGED IN TRANSIT

When delivering the equipment to you, the truck driver or carriers’ 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.

Do not return any merchandise without first contacting Broadcast Electronics and receiving prior

written approval and a 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 the circumstances and reasons when requesting return of merchandise. 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. We can assume no liability for inbound damage, and necessary repairs become

the obligation of the shipper. All returned merchandise must be sent freight prepaid and properly

insured by the customer

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

(see next page.)

RF TECHNICAL SERVICES

Telephone: +1 (217) 224-9617

E-Mail: rfservice@bdcast.com

Fax: +1 (217) 481-7018

FACILITY CONTACTS

Broadcast Electronics, - Quincy Facility

4100 N. 24th St. P.O. BOX 3606

Quincy, Illinois 62305

Telephone: +1 (217) 224-9600

Fax: +1 (217) 481-7108

General E-Mail: bdcast@bdcast.com

Web Site: www.bdcast.com

PARTS

©2021 Broadcast Electronics

iv

Telephone: +1 (217) 224-9617

E-Mail: parts@bdcast.com

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.

SAFETY PRECAUTIONS

PLEASE READ AND OBSERVE ALL SAFETY PRECAUTIONS

DANGEROUS HAZARDS EXIST IN THE OPERATION OF POWER TRANSISTORS

The operation of 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 VOLTAGES & CURRENTS –

supplies and;/or batteries used in RF amplifier circuits can supply very high currents.

B. HOT SURFACES –

AC mains voltages can be deadly. DC power

Certain areas of the equipment, heat sinks and components may be

operating well above ambient temperature. In particular are the junction temperatures

of power transistors which can reach temperatures of several hundred degrees

centigrade and cause serious burns if touched

C. RF BURNS -

RADIO FREQUENCY RADIATION

not operate an RF power module with the covers removed.

RF power transistors and their circuits may contain high RF potentials. Do

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

2

working areas where personnel heat load is above normal. A 10 mW/cm

per one tenth hour average

©2021 Broadcast Electronics

v

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/cm

as the standard employee protection guide (ANSI C95.1-1982).

per one tenth hour average level exposure between 30 Hz and 300 MHz

2

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.

IC RSS-GEN, Sec 8.3 Warning Statement-

(Required for Transmitters w/ detachable antennas)

ENGLISH:

This radio transmitter 131A-GTX900 has been approved by Industry Canada to operate with the

antenna types listed below with the maximum permissible gain and required antenna impedance

for each antenna type indicated. Antenna types not included in this list, having a gain greater

than the maximum gain indicated for that type, are strictly prohibited for use with this device.

FRENCH:

Le présent émetteur radio 131A-GTX900 a été approuvé par Industrie Canada pour fonctionner

avec les types d'antenne énumérés ci-dessous et ayant un gain admissible maximal et

l'impédance requise pour chaque type d'antenne. Les types d'antenne non inclus dans cette liste,

ou dont le gain est supérieur au gain maximal indiqué, sont strictement interdits pour

l'exploitation de l'émetteur.

Note: RF EXPOSURE SAFETY DISTANCE

RF Exposure Limits for Canada, according to IC regulation: setting to the maximum of the

output power of the apparatus, to guarantee the limits of exposure declared within this

document, it is necessary that the antenna gain used with this device should be 0dBi or less

and all persons should maintain a minimum separation distance of 0.4736 m (47.36 cm)

for general uncontrolled exposure and general controlled exposure.

For FCC standards, a safety distance of 0.4736 m (47.36 cm) is declared.

Limites d’exposition RF: en réglant au maximum de la puissance de sortie de l’appareil, afin

de garantir les limites d’exposition déclarées dans ce document, il est nécessaire que le

gain d’antenne utilisé avec cet appareil doit être de 0 dBi ou moins et toutes les personnes

doivent conserver une distance de séparation minimale de 47.36 cm pour les expositions

générales non contrôlées et les expositions générales contrôlées.

©2021 Broadcast Electronics

Table of Contents

vi

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

General Description ................................................................................................................................................ 9

Transmitter Review ............................................................................................................................................. 11

Receiver Review .................................................................................................................................................... 13

GTX and GRX Overall Data ................................................................................................................................. 15

GTX Transmitter Only ......................................................................................................................................... 16

GRX Receiver Only ................................................................................................................................................ 17

Rack Mounting and Cooling .............................................................................................................................. 19

Control Functions .................................................................................................................................................. 19

GTX Parallel Remote ............................................................................................................................................ 19

GRX Parallel Remote ............................................................................................................................................ 20

Battery or DC Supply ........................................................................................................................................... 20

3.5.1

Notes on battery and wiring .................................................................................................................................. 20

Password Organization ...................................................................................................................................... 23

Factory Default Passwords ............................................................................................................................... 23

Display Menus and Navigation ........................................................................................................................ 23

4.3.1

START & DEFAULT FIELDS ................................................................................................................................... 24

Timeouts and Default Fields ........................................................................................................................ 24

Field INIT: Initialization Display ............................................................................................................... 25

Field #00: Escape / Default Display .......................................................................................................... 25

Field #01: Operation / Setup Selection ................................................................................................... 25

Field #20: Enter Password............................................................................................................................ 25

OPERATION MENUS ........................................................................................................................................ 27

Field #02: Direct & Reflected Power ........................................................................................................ 27

Field #04: Multiplex Signal Level (Output Modulation) .................................................................. 27

Field #05: Left & Right Signal Level in dB .............................................................................................. 27

Field #06: L & R Signal Level / Analog Meter ....................................................................................... 27

Field #07: RDS / SCA Auxiliary Modulation Level .............................................................................. 28

Field #09: Internal Voltages ......................................................................................................................... 28

Field #10: Temperature, Data and Clock ................................................................................................ 28

SETUP MENUS .................................................................................................................................................... 29

Field #21: Local/Remote control setup .................................................................................................. 29

Field #22: Transmission Frequency setup ............................................................................................ 29

Field #23: Output Power setup ................................................................................................................... 29

Field #24: LF Modulation Input Level setup ......................................................................................... 29

Field #25: Auxiliary Input Level setup .................................................................................................... 30

Field #26: Limiter setup ................................................................................................................................. 30

Field #27: Transmission Mode, and Pre-emphasis Setup ............................................................... 31

Field #28: Reference Deviation setup ...................................................................................................... 31

Field #29: Display Contrast setup ............................................................................................................. 31

Field #30: Time & Date setup ...................................................................................................................... 31

Field #31: Elapsed Time ................................................................................................................................ 31

Field #32: Password Management ............................................................................................................ 32

Field #33: Alarm Setup and Display ......................................................................................................... 33

Field #34: I/O Pin Allocation and Logic Level setup ......................................................................... 33

4.3.2

TRANSMITTER FIELDS & MENU TREE ............................................................................................................. 26

©2021 Broadcast Electronics

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

4.3.3

RECEIVER FIELDS & MENU TREE ....................................................................................................................... 35

Field #35: Synthesis setup ............................................................................................................................ 34

Field #37: Ethernet & Lan setup ................................................................................................................ 34

OPERATION MENUS ........................................................................................................................................ 36

Field #02: Receiver Frequency ................................................................................................................... 36

Field #03: Received RF Field and Muting ............................................................................................... 36

Field #04: MPX Modulation and Reception Field ............................................................................... 36

Field #04Modulation of the Multiplex Signal ....................................................................................... 36

Fields #05 & #06: L and R Decoded Output Levels............................................................................ 36

Field #08: Stereo Pilot Frequency level .................................................................................................. 37

SETUP MENUS .................................................................................................................................................... 37

Field #22: Frequency setup .......................................................................................................................... 37

Field #24: LF Output Level setup ............................................................................................................... 37

Field #25: Receiver Muting setup .............................................................................................................. 37

Field #26: De-emphasis setup ..................................................................................................................... 38

Field #28: Optional Boards Detection ...................................................................................................... 38

Field #33: Alarm setup and display .......................................................................................................... 39

Field #34: I/O pin allocation and logic level setup ............................................................................ 39

Field #36 Left & Right Level ......................................................................................................................... 40

Field #37 Headphone Volume ..................................................................................................................... 40

Field #39 Serial Number ................................................................................................................................ 40

Transmitter Drawings ......................................................................................................................................... 42

5.1.1

GTX Mechanical Layout – VHF & UHF Models ............................................................................................... 42

Receiver Drawings ................................................................................................................................................ 43

5.2.1

GRX Mechanical Layout – VHF & UHF Models ............................................................................................... 43

vii

©2021 Broadcast Electronics



Figure 1 – GTX Transmitter Block Diagram ................................................................................................................ 11

Figure 2 – GTX Transmitter Rear Panel ........................................................................................................................ 12

Figure 3 – GRX Rear Panel .................................................................................................................................................. 14

Figure 4 - GTX & GRX Remote Connectors .................................................................................................................. 19

Figure 5 – Transmitter Menu Tree .................................................................................................................................. 26

Figure 6 - Receiver Menu Tree .......................................................................................................................................... 35

Figure 7 – Transmitter Mechanical - VHF & UHF Models .................................................................................... 42

Figure 11 – Receiver Layout - VHF & UHF ................................................................................................................. 43

Figures

Tables

Table 1 – Battery Life ............................................................................................................................................................ 22

viii

©2021 Broadcast Electronics

9

OVERVIEW

BROADCAST STL FAMILY SERIES

Marti GTX / GRX

VHF / UHF & SHF Bands

General Description

The Marti GTX/GRX series STLs are the result of experience gained by Broadcast Electronics during

years of producing FM broadcast equipment, transmitters, STL and stereo encoders.

These radio links were specifically designed to comply with the latest international standards and

the requirements of advanced broadcasters, meeting tighter specifications than usually required, at

an affordable cost.

Great care was spent into producing a Hi-Fi-quality modulated signal, with low residual noise and

distortion. The RF signal is also free from spurious and harmonic components to a higher degree than

required by USA, CCIR, European, and most other national standards.

To obtain this outstanding performance, Broadcast Electronics strongly recommend relying on

qualified personnel to install and verify the equipment which makes up the radio station, i.e. the STL,

the transmitters and the power amplifiers, the corresponding antennas, cables and connectors. This

will assure to achieve the best performance and stability in time.

To this aim, Broadcast Electronics especially recommend that their equipment should not be

tampered with by unskilled personnel and its after-sale service is available to customers for any

technical problem. Before proceeding to installation, please carefully read at least the general

installation part of this manual, to gain confidence with the equipment.

This equipment is very stable and changes to the internal pre-setting other than frequency and few

other options are not usually required, however if they are, once again they must be done by skilled

personnel, with proper instrumentation and service documentation. Improperly tampering with the

settings may harm the apparatus or jeopardize the guaranteed performance.

EN300454-1/2 AND ETS301489-01/11

THIS EQUIPMENT COMPLIES WITH ALL RELEVANT EMI/EMC AND SAFETY REQUIREMENTS,

ETSI

STANDARDS.

NO INTERNAL ADJUSTMENT OR PRESETTING IS REQUIRED DURING NORMAL OPERATIONS. THE

APPARATUS SHALL BE PROPERLY EARTHED AND OPERATED WITH ALL COVERS CLOSED WITH

ALL FASTENTERS TO PREVENT ELECTRICAL HAZARDS AND COMPLY WITH THE EMI & EMC

STANDARDS.

©2021 Broadcast Electronics

10

The Marti GTX transmitter and its companion Marti GRX receiver are the core of a high quality,

synthesized studio-to-transmitter link (STL), to be used for broadcast repeaters in conjunction with

any standard FM or AM transmitter. They’re an evolution of the established Marti GTX/GRX series

STL whose main circuitry is still extensively used here with a new controller, user interface and

software and more advanced oscillators in a compatible 2RU, 19" case.

They allow the reception of mono or stereo signal and its retransmission without using any

additional stereo-coder on the receiving end: in both cases the LF output signal from the receiver

must be sent to the stereo input (linear or not pre-emphasized) of the local FM rebroadcast

transmitter.

The STL is built for several different frequency slots from VHF to the SHF range. Two main models

are built: one for the 200 - 960 MHz and the other frequencies in the SHF band. While the, controls,

basic circuitry and the performances are the same, some internal components vary or are specifically

tuned as required to cover this wide frequency band. Usually these components are the local

oscillator, the power amplifier and the input/ output filters. The factory adjusted frequency slots are

10 to 50 MHz wide and must be specified in the order. In the preset sub-range, the frequency and

power of the transmitter may be freely changed on the field. The receiver may require some more

adjustment for wider frequency displacement: in fact the adoption of narrow, low loss input filters

permitted to achieve the best possible rejection of interfering signals in the band at the expense of

some frequency agility. So nearly 8-10MHz may be used without any retouching but wider variation

up to 50-60MHz will require retuning of the input filter.

Being the apparatuses are completely digitally controlled, they are extensively on field

programmable by front panel or remotely in every respect. The alphanumeric display permits easy

and accurate metering, adjustment and continuous monitoring of modulation levels, power,

operation and internal parameters. All this information is externally available on the same RS232 I/O

port that maybe used to remotely control the transmitter. In addition to the serial I/O, some signals

and controls are available on a parallel I/O socket for easy interfacing with others analog controllers

or supervisory systems. A powerful 3-levels password management permits a very high degree of

security and privacy as may be required in different situations.

The LF input and output levels are precisely adjustable over a broad range, by means of 0.5dB

stepwise variable attenuators. The transmitter has also an auxiliary input, specifically designed for

RDS and SCA encoders. A modulation monitor output permits to control other transmitters or STL's

with the same internally processed high-quality mpx signal. Furthermore, the system is optimized to

be compatible with external digital companding encoder/decoders and to provide RDS and SCA

signals, with almost no attenuation.

Optional top-quality stereo encoder/decoder boards maybe factory installed on the transmitter/

receiver or field retrofitted with minimum required technical skill. The powerful internal software

and monitoring functions recognize their presence and enable the functions. A universal switch-

mode power supply permits operation in the extended 95-250 VAC range with no intervention and a

24 V back-up battery input is provided too.

©2021 Broadcast Electronics



11

Transmitter Review

The transmitter and receiver set are fitted in the same sized cabinet and are nearly identical on the

front view. In fact they differ for the name on the front panel and the display and for the rear panel

connector's accommodation.

Both are clean and easy to control from the front panel through a single knob. The wide display and

simple self-explanatory menu allows navigation through the various options. A single fast push on

the jog knob acts as an "Enter" or confirmation while pushing for a longer time is interpreted as

"Escape".

Some LEDs signal at a glance proper functioning and warning states. Two red led signal warning

status, "Alarm" and "Limiter". A bi-stable yellow/green led signals "On the air" while a fourth one

signals "PLL Lock": both these two should be green in correct operation.

An RF Monitor output connector is located on the front panel for easy test on the field

An RF Circulator, aka Isolator, is used on models in the SHF band. The Isolator is not required on the

VHF/UHF bands

Figure 1 – GTX Transmitter Block Diagram

©2021 Broadcast Electronics

12

Figure 2 – GTX Transmitter Rear Panel

All equipment inputs and outputs but RF monitor are located on the rear panel. They are:

1.

2.

3.

4.

5.

6.

7.

8.

The mains supply IEC320-type outlet, which incorporates the mains On/Off switch and

the fuses. The internal power supply operates in 115/230 VAC mains range without any

internal or external preset or switching.

An additional chassis screw for system earthing and a 24V-battery backup socket pair.

The RF antenna connector, N-type

The L & R stereo analog audio channels input on balanced XLR-type connectors (L input

is used only with internal Stereo Encoder option).

The AES/EBU stereo digital audio input on a balanced XLR-type connector which may be

used as an alternative to the analog input (this is a special option and may be used only

in conjunction with the internal Stereo Encoder option).

The wide-band external processed stereo or composite signal input on a grounded

unbalanced BNC connector

A frequency limited (20k 100kHz) auxiliary channel input on a grounded, unbalanced

BNC connector for a RDS or SCA signal.

An LF modulation output for monitoring, RDS external synchronization or re-

broadcasting purpose, BNC-type

9.

A RS232 Dsub9 female remote serial control port, inverted wired.

10.

A parallel control port, Dsub9 male type

©2021 Broadcast Electronics



Receiver Review

Like the Transmitter, the Receiver front panel accommodates the single control knob, the display,

four LEDs for immediate status control and a single output connector for IF monitoring.

Here too regular operation is signalized by green LEDs: "PLL Lock" and "Field". This latter is a bi-

stable and lights in yellow when RF field is too low or absent. As in the Transmitter red LEDs signals

improper operation. The first one, "Modulation", is activated by low or absent modulation; the last

one is the general "Alarm" LED.

13

Figure 3 – GRX Block Diagram

©2021 Broadcast Electronics

14

Figure 3 – GRX Rear Panel

The Receiver I/O connectors on the rear panel are:

1.

2.

3.

4.

5.

6.

7.

8.

The mains supply IEC320-type outlet, which incorporates the mains switch and the

fuses.

An additional earth screw for system earthing and a 24V-battery backup socket pair.

The RF antenna connector, N-type

The main composite signal output (Mpx+, Mpx-) on two BNC-type connectors in

antiphase, permitting direct drive of two separate transmitters or one in balanced mode.

A buffered LF monitor, BNC-type connector that maybe internally connected as an

additional composite or wide-band or mono signal output.

The filtered/de-emphasized mono signal on a balanced male XLR-type connector.

The L & R audio channels output sockets on balanced XLR-type connectors only with

(Internal Stereo Decoder option).

A RS232 Dsub9 female remote serial control port, inverted wired.

9.

A parallel control port, D-Sub 9 male type

©2021 Broadcast Electronics



TECHNICAL SPECIFICATIOINS

GTX and GRX Overall Data

Frequency Ranges in MHz, specified on order

Model

Standard Freq Range (MHz) Alternate Range (MHz)

15

210-260

310-370

N/A

850-900

900-940

FM 75kHz peak deviation.

(215 – 960 MHz)

180kF3E mono

256kF3E stereo

215-270

300-360

400-470

830-854

940-960

GTX/GRX200

GTX/GRX300

GTX/GRX400

GTX/GRX800

GTX/GRX900

(Other ranges on request)

Modulation:

Synthesis Step

10kHz

25kHz (1.3 – 2.5 GHz)

Composite Output Response:

+0.1/-0.5dB

<-6 dB

<-20 dB @ 125 kHz

Monitor Output Wideband Response:

Mono/Stereo Response:

S/N Ratio (30÷20000Hz RMS):

>75 dB, 80 typ. Mono

>72 dB, 76 typ. Stereo

+0.1/-1.5dB

-3 dB typ.

-6 dB typ.

±0.2dB 0 Hz ÷ 15 kHz

15 Hz - 67 kHz

@ 100 kHz

15 Hz ÷ 100 kHz

@ 125 kHz

@ 160 kHz

©2021 Broadcast Electronics

16

0.10% 0.03% typical.

0.30% 0.20% typical.

0.25% 0.12% typical.

0.30% 0.20% typical.

≤

≤

≤

≤

Mono

Stereo, 1ch

Mono

Stereo, 1ch

>50 dB 400 - 10000 Hz, typical

>40 dB 100 - 15000 Hz, typical

Modulation Distortion @ 100% dev

@ 1 kHz/

@ 30 - 7500 Hz

Stereo Crosstalk:

Input/Output:

Alarm

Remote Control/Lock

RS232 for Monitoring and Control

Power Input Requirements:

95 / 250 VAC 50/60 Hz

22.0 - 28.0 VDC

Operating Temperature Range:

recommended.

max.

0 - 35° C

-10 - 45° C

GTX Transmitter Only

RF/LF disable, Low RF field

<2,5 ppM

<1 ppM/year

7W / 15W (215÷960 Mhz)

2W / 5W (1.4÷2.6 Ghz)

Frequency Error:

Frequency Drift:

RF Output Power:

Max Ref Pwr Allowed: 1W / 2W

<-60 dBc

RF Harmonics:

RF Spurious:

RF Output:

Audio/Input Level:

Audio/Input:

Common Mode Rejection:

Audio Input Connectors:

Auxiliary Input Level:

10k ohm / BNC-type

Auxiliary Input:

Monitor LF Output:

Pre-emphasis

S/N, 30 Hz – 20kHz

©2021 Broadcast Electronics

<-70 dBc, -80 dBc typ.

50 ohm, N connector

-3.5 ÷ +12.5dBm

@ ± 75kHz deviation

10k ohm/600 ohm, bal./unbalanced

>50 dB, >60dB typ. (20÷15000 Hz)

Female XLR

-12.5 ÷ +3.5dBm @±7.5 kHz dev.

-24 ÷ -8dBm @±2 kHz dev.

0 ÷ +10 dBm @ ±75kHz dev.

0/50/75 μs ±2%

>77 dB, 82 typ. Mono

>74 dB, 77 typ. Stereo

17

Distortion, 30Hz – 15kHz:

Stereo Crosstalk:

Audio Response,

30Hz - 15 kHz: ±0.1dB

Out of Band Audio Attenuation:

Deviation Limiter:

Composite Response:

10 Hz÷100kHz

Auxiliary Response:

10÷ 100 kHz

Power Input:

Battery Input:

±

0.1dB

Dimensions, less handles:

GRX Receiver Only

<0.02% @ 75kHz dev.

>50 dB (100÷5000 Hz)

>45 dB (50÷15000 Hz)

≥

>50 dB @ F

0 - +7.1 dB, adjustable

19 kHz

±

0.2dB

50 W max @ 90/250Vac (Po= 5W)

≤

80 W max @90/250Vac (Po=15W)

≤

1.8A @ 24 Vdc (Po= 5W)

3.0A @ 24 Vdc (Po= 15W)

19" 2RU,

19.0 x 3.46 x 12.6 in

483 x 88 x 330mm

≤9 dB

≥60 dB 70 typ.

>+10dB typ @ δF=300 kHz

>+35dB typ @ δF=500 kHz

>+45dB typ @ δF=1.0 MHz

>45 dB

-90 ÷ -10dBm, (7μV÷70mV)

Sin= -90dBm (7μV) Mono

Sin= -70dBm (70μV) Stereo

10.7 MHz / 0dBm

Receiver Noise:

Image Frequency Rejection:

Dynamic Selectivity:

AM Suppression:

Usable Input Level:

Sensitivity (typical):

(S/N=60dB)

IF Monitor Output:

Mono or Stereo Decoded Response:

Out of band Mono or Stereo Audio Response:

De-emphasis Time Constant:

S/N Ratio, (30÷20000 Hz. rms):

>50 dB @ F≥19 kHz

0/50/75μs ±2%

30 Hz ÷ 15 kHz ±0.1dB

>72 dB, 76 typ. mono

>70 dB, 73 typ. stereo

©2021 Broadcast Electronics

18

Distortion @ 1kHz / 100% dev.

-

Stereo Crosstalk:

Power Input:

Battery Input:

Dimensions, less handles:

Mono ≤0.1%, 0.03% typ.

Stereo ≤0.3%, 0.20% typ.

>50 dB (100÷5000 Hz)

>45 dB (50÷15000

15 W max @ 90/250Vac

≤0.4A @ 24 Vdc

19" 2RU,

19.0 x 3.46 x 12.6 in

483 x 88 x 330 mm

©2021 Broadcast Electronics



INSTALLATION

Rack Mounting and Cooling

It is very important to install the apparatus on a stable stand/rack, in such a way to permit good

ventilation to the rear heatsink

Since the STL equipment is cooled by convection in air, allow a 1RU clearance above and below the

equipment. This especially important for heat sink in the rear of the transmitter

Control Functions

Both the STL Transmitter and Receiver are set and controlled by the front panel keyboard and

display. The same functions can be remoted via the parallel control port and a future serial RS232

port. Both of these 2 ports are located in the right rear of the Transmitter and Receiver.

Remote Control Parallel Port

This is the primary port to accommodate control and monitoring functions on this DB9 male

connector. Many of the I/O lines may be assigned to different functions and logic polarity may be

changed as needed for the sites remote control equipment. Default pin assignment is listed in Section

3.2 for the Transmitter and Section 3.3 for the Receiver.

RS232 Port (Factory)

The RS232 port is a factory connection location for installing software control options. Other than

this use, no connection is required to this port for installation.

19

Figure 4 - GTX & GRX Remote Connectors

GTX Parallel Remote

Pins 1, 5, 8

Ground.

Pin 2,

10kOhm signals that the transmitter delivers substantial RF power. It is not granted that the output

power is exactly as preset.

“On Air” output. Open collector transistor circuit with a resistive pull-up: at +12V

Pin 3,

Forward power output. A signal proportional to forward power, aka direct power,

with a pseudo square law. Range is 0-5Vdc / 1k impedance. Full power voltage ranges 3,5 to 4 V.

©2021 Broadcast Electronics

20

Pin 6,

A shorted circuit to ground disables RF. Maximum voltage and current available are roughly +10V

and 1mA.

RF enable input. Base input of a common emitter transistor with a resistive pull-up.

Alarm output. Open collector transistor circuit with a resistive pull-up: logic low

Pin 7,

signal means alarm condition. Correct functioning is signaled by +12V with10kimpedance.

Maximum current sinking capability <10mA.

Pins 4 & 9

Reserved for future upgrades.

GRX Parallel Remote

Pins 1 & 5

Ground.

“Modulation OK” output. Open collector transistor circuit with a resistive pull-up: a

Pin 2,

low logic state signals modulation is present on the received signal. On the contrary, a high logic

state, + 12V / 10kOhm, warns on modulation loss. As alternate function the pin may be assigned to

signal “remote lock” status.

Pins 3 & 8,

“Field Good”. The insulated contacts of a relay are wired to these pins: the relay is

default driven by the received RF. When the field exceeds the preset threshold, the relay is excited.

The contacts may be chosen through an internal bridge to be "normally open (n.o.)" or "normally

closed (n.c.)". Factory default is "n.o.". Alternatively, the relay may be assigned to “Alarm”

"LF Disable" input. Base input of a common emitter transistor with a resistive pull-

Pin 6,

up. A shorted circuit to ground disables main LF outputs. Maximum voltage and current available are

nearly +10V and 1mA. Alternate function is “Remote lock”: when chosen, a shorted circuit disables

front panel setup functions.

“Alarm” output. Open collector transistor circuit with a resistive pull-up: a logic low

-Pin 7,

signal means alarm condition. Correct functioning is signaled by +12V with10k

Maximum current sinking capability <10mA. This pin may be alternatively assigned to signal “Field

good”

-Pins 4 & 9:

Reserved for future upgrades.

impedance.

Ω

Battery or DC Supply

The Marti GTX/GRX include a low voltage d.c. power supply input with battery management, to

permit continuous d.c. power supply or back-up in case of mains failure. This input, whose nominal

voltage is 24 V negative grounded, accepts a dc supply which may range 22 - 28 V in absence of mains

supply. It delivers a regulated +27.6V to permit battery charging, when mains supply is present.

Front panel switch do not acts on d.c. supply, which is always on when applied to its terminals on the

rear panel. There is no switch in series to this supply but only a diode and a self-reset fuse to protect

from polarity reversal.

Voltage higher than 28Vdc applied to or current sunk from this input for different purpose than

battery charging may seriously impair the equipment power supply.

3.5.1

Notes on battery and wiring

Any kind of battery may be used, provided it has the correct voltage (24 V, nominal) and an adequate

capacity. Price / performance considerations may suggest plumb batteries, regular or sealed.

©2021 Broadcast Electronics

21

We suggest using sealed batteries for small systems, 20 to 40 A/hour rated. Higher capacities, like 40

± 100 A/hour and more, may be achieved at low cost from car-type batteries: in this case always

install the batteries in a well vented place, because acid gas produced during battery charging may

damage the electronic equipment.

GTX and RTX battery inputs may be wired together to the same battery array, provided they both are

internally set to 27.6V, as regular. In this case the power supplies appear to be in parallel (with some

redundancy) and they both charge the battery array at a higher rate.

Plumb batteries are usually made up to 12 V nominal voltage, so two batteries are required in series.

Wire them with proper section wire: 1 sq. mm is usually enough to connect them to the transmitter

and/or the receiver; bigger sections may be used in case of long wiring.

Install batteries capable of sustaining the system for the maximum foreseen period of mains failure.

Avoid to completely discharging the batteries or permanent damage may occur to them. Even if the

battery manager disconnects the battery when the voltage is lower than 22V, a small test current,

nearly 10-15mA is sunk by the circuitry in absence of mains power. This current is capable to deeply

discharge the battery array in case of prolonged mains absence. Always remove the battery array if

the system is off-line

1.

Battery Life

We recommend following the literature from you battery manufacturer for correct installation and

maintenance of the battery system. In absence of that literature, some common practices:

- Use batteries whose capacity is at least 2.5 - 10 times higher than the maximum expected power

absorption, on prolonged mains loss.

- Never permit batteries to undergo below minimum safe voltage, on prolonged discharges.

Following these guidelines, battery life expectation may range from 2 to 5 years, depending on duty

factor and temperature (low temperature decreases the capability but increases the life).

2.

Back-up and recharge time

An estimate of the backup time, i.e. the capability of the batteries to power up the equipment in case

of mains failure, may be done by considering that:

- The manufacturers usually specify the nominal capability of a battery, discharged in a period of 10

or 20 hour.

- For discharge faster than 10 hour, the capability will be reduced. For slower discharges, it may be

increased. Typical values are 70 % for discharge in 2 hours and 110 %, for discharges in 50 hours.

- The capability will diminish with time and usage: typical derating may be 10 -30 % / year.

- Taking in count all previously said, with a real capability which is derived from the nominal one

with the suggested corrections, the backup time is given by the capacity in A/hour divided the

absorption of the equipment which makes up the load, in A.

- The supplied recharge current delivered by the equipment is nearly 0.5-1.0 A by the GTX and 1.5-

2.0A by the RTX18, when the batteries are almost discharged.

- While the charge voltage is roughly constant, the charge current is not. The charge time may be

rather long, even some day, especially in case of deep discharge and heavy load on the equipment

As a reference we give the following table with estimated maximum backup times for some

combinations of equipment and batteries, which are valid only for new, fully charged batteries. The

current absorption for GTX transmitter is typical for SHF version @ 5W output power or a 900MHz

version @ 10W.

Higher output power will increase this absorption up to 20-30%, while lowering the output power

will reduce the current absorption to roughly the same 20-30%.

©2021 Broadcast Electronics

22

GTX

Table 1 – Battery Life

GRX

GTX +

GRX

Unit of

Measure

Main Consumption

Backup Time with

20A/Hour Battery

Backup Time with

40A/Hour Battery

Backup Time with

100A/Hour Battery

1.95

9

20.5

52

0.45

44

44

50

2.4

7.5

16.5

16.5

Amps

Hour(s)

Hour(s)

Hour(s)

©2021 Broadcast Electronics

23

SET UP

For first time users of the GTX and GRX, allow some time to become familiar on how to navigate the

operation and setup menus before putting the equipment into “On Air” service.

Password Organization

As a factory default, the equipment is delivered without any access restriction. The passwords are

“OFF” in both the Transmitter and Receiver. The managing of the password function is optional and

we recommend its use only where needed

The password organization is set in 2 security levels, each with its own password. If password

management is desired, enable both levels. The higher Level 2, permits setup access and changes

while the lower Level 1 is restricted to monitoring only.

The password is 4 alphanumeric characters, including upper and lower case, plus several special

symbols. The complete password is masked by dummy characters “****" until the curser is moved to

each position for selecting the character and then reverts back to a dummy character when the

curser is moved to the next position. The correct or confirmed password is never shown unless an

incorrect password is entered.

Level 1:

The two levels are defined as follows:

•

Lower security level

Level 2:

•

•

•

•

If restriction is desired to prevent access to the Setup menus, then this Level can be set

to "ON”. With the Level 1 password enabled, the “Enter Password” field is activated

when navigation to the Setup menu is attempted. Failure to insert a correct password

will prevent access to Setup menu and a time-out, typically a length 3 minutes, expires to

return back to Operation menu.

Again, the factory default is set to "OFF", and any user is permitted to freely navigate

through the equipment's monitoring menu information. We suggest leaving it in this

state if users are expected to access most of the monitoring and control menu fields.

Service level

This password is used for restricting access to make changes in the Setup menu, such as

frequency, RF power, audio input & output levels and other operating parameters.

Its use is reserved to personnel who need wide access to the equipment setups and

functions. After installation and the equipment checked out is completed, it is

recommended to change the default factory state of "OFF" and enable the Level to ON,.

.

Factory Default Passwords

Level 1:

These are the two factory default passwords:

Level 2:

P001

P002

Be sure to enable and setup the 2nd Level if passwords are going to be used in your STL

system.

Display Menus and Navigation

Rotating the jog knob counterclockwise or clockwise will scroll up and down the menu displays or

within a field to view the submenus when a field is entered. A quick push or tap on the knob will

©2021 Broadcast Electronics

24

function as an "Enter" or “Select” or “Confirm” command. A longer push or “Hold” of the knob will be

interpreted as an "Escape" to abort the operation. Hold the knob in for 3 seconds to ensure Escape is

Refer to Figures 5 & 6, Menu Trees, and the Sample Menu below

recognized.

A numbering system is used in the Menu Trees to provide a quick look up of the various display

descriptions, such as the #22 circled below.. In the manual, the term Field is used and it is

synonymous with the terms display, screen or window, but it also represents the function and its

subset of displays as required for that function

Two menu trees are diagrammed in Fig 5 & Fig 6, a Transmitter Menu Tree and Receiver Menu Tree.

Both diagrams have the OPERATION on the left, and SETUP on the right of the tree, with the center

displays being organized in section 4.3.1.

•

4.3.1

START & DEFAULT FIELDS

These fields are #01, #02, #00, #20, and INIT. The term Start is relative since most of these fields

may be a “Starting Point” in navigation, depending on the last status of the GTX or GRX control.

1.

2.

3.

4.

Knob Hold 3 Seconds

Timeouts and Default Fields

Local Input Timeout. 60 Seconds

Escape when needed and returns you to field #11.

…As stated above, holding the knob in for 3 seconds provides an

When a Setup field is entered, and the knob is not

Default Timeout 3 minutes

touched or turned within 60 seconds, this timeout will activate and return back to “select a

field” status in the same branch.

. If a Setup field is not selected within 3 minutes, the

equipment navigates back to the Operation branch of the menu tree. It will also activate in

the event a lock up occurs during data entry such as in a password entry. The navigation

back to the Operation branch will typically reset on field #02. In some timeout conditions

the field may be

AC Restart

. An alternative to waiting for a 3 minutes timeout, is to do an AC restart. The

equipment will follow the normal boot up and navigation to default field #02 in the

Operation menu.

When any security level is enabled, the equipment stops access following a default timeout. The

functioning of the equipment is not influenced by this state such as RF output and modulation.

©2021 Broadcast Electronics

25

Field INIT: Initialization Display

This field only displays when the equipment is turned on from mains power and the field is not used

in other navigation. The display is very brief, typically less than 4 seconds, before advancing to the

next field after. The first line of the display illuminates in a r pixel test, and then changing to the

word INITIALIZING, with the model and software release displayed in the second line. The first line

will then change and display an internal option(s) if present.

STEREO ENCODER: YES

Gtx15/2b – rev 1.59

In this example, the transmitter shows the presence (YES) or (NO) of the internal Stereo Encoder

option, before advancing to Operation Field #2.

Field #00: Escape / Default Display

BE – MARTI Gtx

Gtx15/2b - rev.1.59

This is the default field that shows the equipment model, the software release and the manufacturer's

name. This is the field the display returns back to when an “Escape” is keyed in.

Choosing between the Operation and Setup branch is immediately proposed after the default field is

displayed. At any time, during navigation of the various fields, "escaping" will return back to the

default field. However, after entering a field to change a parameter, then an escape puts you back to

the last navigated field.

Field #01: Operation / Setup Selection

As the title states, this field allows the Operation or Setup menu branches to be selected by pressing

the one that is highlighted. . Turn the knob to highlight and select which menu branch is desired to

enter. It is not possible to pass from the Operation branch directly to the Setup without passing

through this field

SETUP

OPERATION

•

•

•

•

Field #20: Enter Password

ENTER PASSWORD

xxxx

This field will not be displayed if both Level 1 and Level 2 passwords are not enabled.

When passwords are enabled, the field will display when or where required and will display the

Level needed for password recognition to allow further navigation or data entry. If the password is

incorrect or the input is terminated by an "escape", the password states as invalid.

©2021 Broadcast Electronics

26

4.3.2

TRANSMITTER FIELDS & MENU TREE

Operation fields #02 thru #10 are described first, followed by the Setup fields. If a field number is

missing or out of sequence, the number is being used in the Receiver Menu Tree to describe a

different function in the menu sequence.

Figure 5 – Transmitter Menu Tree

©2021 Broadcast Electronics

•

•

•

•

27

OPERATION MENUS

Pd 20W Pr .2 W

Field #02: Direct & Reflected Power

XXXX |

This field shows the forward or “direct” power, Pd, and the reflected power, Pr, in the VHF models.

Transmitter models in the SHF band will not show the reflected power as a circulator is used in the

final RF amplifier stage in this band.

•

MPX 75.0kHz + 0.0dB

Field #04: Multiplex Signal Level (Output Modulation)

############# |

This field shows the actual peak modulation level in dB referenced to the peak deviation in kHz. A

pseudo-analog moving bar functions as a modulation meter, leaving a peak mark at its end for 1 or 2

seconds. A vertical bar (|) on this line marks the 0dB position.

LEFT level - 3.0dB

Field #05: Left & Right Signal Level in dB

RIGHT level - 3.5dB

This field shows the actual left and right peak modulation in dB referenced to 75kHz. The right

channel level has no meaning in the absence of an internal stereo-encoder.

aliasing

The reading is fairly accurate with real audio signals. Some steady state test tones, especially at very

low audio frequency, may beat with the discrete ADC conversion sometimes producing reading

uncertainty (

measure.

). In this case the MPX level reading will still correct overall modulation

Field #06: L & R Signal Level / Analog Meter

L########### O |

R######### O |

This field shows the actual left and right peak modulation as two moving bars. A vertical line marks

0dB position and the same considerations as in the previous menu are still valid.

©2021 Broadcast Electronics

28

•

•

•

Field #07: RDS / SCA Auxiliary Modulation Level

AUX 2. 0kHz -31.2dB

#########O

|

This field shows the actual modulation for an auxiliary SCA or RDS signal in dB referenced to 7.5kHz

or 10% of max peak modulation. The usual level for SCA signal is 0dB (7.5kHz) while standard RDS

modulation needs to be set at -11.5dB (2kHz)

Vs2

Vs-

Vs+

Field #09: Internal Voltages

+27.5V +12.5 -12.4

This field shows the internal regulated power supply voltages. The Vs+ and Vs- voltages on the GTX

& GRX models will typically operate +12.5 ±0.3V and -12.4V (+1/-2V).

The Vs2 battery voltage usually reads Vbat= +27.4 ± 0.4V, when the battery is completely charged

and AC mains are on. In case of battery operation, the equipment works satisfactory at any level the

range of 22 to 28V.

Field #10: Temperature, Data and Clock

T(A/H) +30°C

n.a.

01 Jan 21 23:51:35

This field shows the equipment’s internal temperature in Celsius (°C). The ambient temperature

sensor is placed just behind the front panel and it may read higher than the ambient temperature. At

full output power and the maximum allowed ambient temperature of +45 °C, the internal

temperature could read up to 5 - 6 °C higher. The field software supports heatsink temperature

reading (Th) which is not measured on this equipment. There is no Temperature management, only

an alarm. Therefore the user is advised not to exceed temperature limits.

Bear in mind that the higher the ambient temperature, the lower the MTBF. As rule of thumb the life

is halved each 10 °C the temperature is increased. Assuming 10 year operating life at +25°C, which is

not unrealistic, it may become 2.5 years at +45°C.

©2021 Broadcast Electronics

29

•

•

•

•

SETUP MENUS

From this menu branch, equipment parameters may be setup or changed. To enter this section and

make changes, Level 2 is required. Some fields are factory set and not intended to change once the

product has shipped.

Field #21: Local/Remote control setup

SETUP CONTROL

LOCAL & REMOTE

The equipment may be controlled either locally from the front panel or remotely from the I/O lines in

the rear port. It is possible to configure the control as shown above, (Remote and Local) or only by

Local or by Remote only. In this case the correspondingly displayed options will be:

If the apparatus is locked on remote, any attempt to access the setup menu will show the following

message:

LOCAL ONLY or

REMOTE ONLY

REMOTELY LOCKED

PRESET TO LOCAL!

Pushing "Enter" twice in succession on the knob will access the control Screen and the "REMOTELY

LOCKED" line will be selected, allowing it to be changed to "LOCAL & REMOTE" (default setting) or

•

"LOCAL ONLY", if requested..

Field #22: Transmission Frequency setup

FREQUENCY SETUP

232.500 MHz

Frequency is set in two steps on either side of the decimal point. In the first step, the integral part of

the frequency to the left of the decimal point. The second step is to the right of the decimal point.

Field #23: Output Power setup

RF POWER SETUP [W]

Set:20.0 Out:20.0

This field permits changing the RF output in accordance with the licensed power level. Two values

are shown: the programmed level (Set) and the actual level, (Out). Small variations between Set and

Out may be allowed to match the licensed power.

.

MPX 75.0kHz + 0.0dB

Field #24: LF Modulation Input Level setup

Nom.input = + 6.0dBm

©2021 Broadcast Electronics

30

•

•

This field sets the main LF input channels sensitivity, i.e. multiplex, left and right channel. Note that

the multiplex and right channel share the same circuitry and the sensitivity is set to the same value

for all audio /multiplex channels, with a differential error (<0.2dB) at any level. Adjustment range is

- 3.5 - +12.5 dBm.

The upper line of the display shows the modulation corresponding to the LF signal currently present,

while the bottom line shows the nominal input level for 100% modulation, (75kHz). Increasing the

nominal input level consequently reduces the modulation, if the modulating signal remains constant.

AUX 2.0kHz -31.5dB

Field #25: Auxiliary Input Level setup

Nom.input = + 0.0dBm

This field adjusts the auxiliary channels input sensitivity. Adjustment range is -12 - +4 dBm to

produce 10% modulation, corresponding to the deviation of 7.5kHz or -20dB in the upper line of the

display. On this line the actual modulation of the channel is shown in real time. On the lower one the

nominal value of the sensitivity in dBm, the parameter on which we act in this screen.

Field #26: Limiter setup

MPX Limiter + 7.1dB

ON

This field sets the limiter action. Threshold level and enable / disable can be adjusted separately. The

limiter may be set to the maximum allowed modulation level for 75kHz-peak deviation, (0dB), so that

the transmitter prevents signals which would exceed this value, or if regulations allow, the limiting

value may be slightly higher to provide some dynamic headroom for some occasional modulation

peaks

It is recommended, not to frequently exceed the limiter threshold with modulation peaks.

Repeatedly exceeding the threshold can cause a heavy audible distortion.

Conversely, setting the threshold to high above the corresponding deviation level would be no

difference with the limiter on or off

©2021 Broadcast Electronics

•

•

•

•

•

31

MODE/PREEMPH. SETUP

Field #27: Transmission Mode, and Pre-emphasis Setup

STEREO PR 75 μS

μ

S) are set up here. The pre-emphasis is only active on audio channels and

The transmission "modes" (MONO R, STEREO, MONO L+R, EXT MPX), and the pre-emphasis time-

constants (0, 25, 50 or 75

not an external multiplex signal.

μ

Set pre-emphasis to the correct standard for your area. Countries in North and South America use 75

S pre-emphasis, while Europe and some other countries will use 50

S

μ

Field #28: Reference Deviation setup

REFERENCE DEVIATION

75 kHz

.The field selects the deviation to reference 0dB of modulation. The standard (default) is 75kHz but

you can choose any value between 5 and 75kHz, and specifically 50, 40 or 25 kHz.

Field #29: Display Contrast setup

DISPLAY CONTRAST

SETUP 5

It is possible to vary the display contrast. The setting range is 0 to 7 .

Field #30: Time & Date setup

DATE & CLOCK SETUP

31 JAN 21 12:45:00

This field edits date or time. The clock is configured for 24 hour clock time.

Field #31: Elapsed Time

ELAPSED TIME

000356 HOURS

This field shows the elapsed time of service whether the transmitter is on the air or in stand-by and

begins counting when AC mains are applied. This is set in the factory and is not a setting that can be

changed.

©2021 Broadcast Electronics

32

•

Field #32: Password Management

PASSWORD LEVEL 1

code=**** status=OFF

This field allows status, ON/OFF and the level, 1 or 2 to be changed as well as the password itself.

When a Level, or Status, or Password is changed, it is always required to confirm the correct

password for that level: For example, we will change the Level 1 status to On by positioning on the

word OFF, then rotating knob to change from OFF to ON. The following request for password is

displayed:

ENTER PASSWORD

....

After the correct password has been entered the screen will change to the following:

CONFIRM PASSWORD 1

P001 N

In the example, the password, “P001”, is displayed in the lower display followed by the letter “N”

indicating the status “ON”. If the example were reversed and we changed the status from ON to OFF,

the steps and confirmation display would be the same except for the letters “FF” to indicate OFF:”

CONFIRM PASSWORD 1

P001 FF

With password enabled, any attempt to access the equipment will cause the request of a correct

password. Failure to do so or an error in entering the password will cause a time-out process during

which no command will be recognized by the equipment. The timeout starts after the last action of

the jog knob plus the default timeout of 3 minutes. After which it will be possible to retry access and

input a valid password.

INVALID PASSWORD!

....

If an incorrect password is entered, it will be necessary to wait for the end of the resulting time-out

before another possibility is granted. The following error message is generated, and the display

remains frozen, preventing further operations until the time-out. Subsequently, it is possible to exit

the Screen with “Escape” and then possibly try again.

©2021 Broadcast Electronics

33

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Field #33: Alarm Setup and Display

This menu shows the various alarm conditions which are associated with the general alarm line,

either located the front panel LED and the remote I/O signaling line. Some of them may be edited for

their threshold level while others are factory set and fixed. The following table lists all them:

ALARM SETUP

ON

TEMPERATURE:

ON

PLL UNLOCK:

ON

HIGH VSWR:

LOW POWER:

ON/OFF

NO MODULATION: ON/OFF

OVERMODULATION: ON/OFF

TEMP. AMBIENT: 55°C TEMP.

HEATSINK: XX°C

MAX REFL.PW: XX.X W

MIN DIR. PW: XX.X W

NO MOD. LEV.:-15.9dB

NO MOD. TIME: 90sec

UNLOCK TIME:

If the alarm is enabled, the red front panel

turn on. At the same time a flashing line will superimpose on the display specifying the highest

priority pending alarm. This alarm line will stop flashing whenever the control jog knob is moved to

permit navigation in the control and setup menus; at timeout, i.e. 2 or 3 minutes from the last access

it will superimpose again till alarm resets. The alarm reset is automatic and requires no action from

the user. The equipment has no alarm historical memory

LED and the corresponding remote signal line will

"Alarm"

60sec

•

•

I/O PIN ALLOCATION

Field #34: I/O Pin Allocation and Logic Level setup

& LOGIC LEVELS SETUP

As described in Section 3.3, there are 3 I/O lines which are associated to corresponding pins of the

parallel remote I/O connector on the rear panel. This field permits setup to the corresponding

function associated to each pin with the following options ("NOT DEFINED" means that no alternate

Inputs:

function is assigned):

PIN 6: RF ENABLE

NOT DEFINED

Outputs:

PIN 2: ON THE AIR

REMOTE LOCKED

PIN 7: ALARM

NOT DEFINED

The factory default value is the one indicated on the first line. Subsequently, on the same menu it is

possible to choose the high or low logic level associated with the alarm. When the equipment is

locked to remote control operation, it is not possible to alter any preselection before unlocking this

control.

©2021 Broadcast Electronics

34

•

•

Field #35: Synthesis setup

SYNTHESIS SETUP

10kHz

This field displays the synthesis step frequency and can be selected,10 or 25kHz

Field #37: Ethernet & Lan setup

Field #37 is for the ETHERNET & LAN hardware option. The control and display software will have

this ready for the option in both the Transmitter and Receiver. Ethernet settings, IP, Mask and

Gateway may be changed in this field. ETHERNET & LAN

SETUP

IP:

The default settings for Ethernet and LAN are as follows:

Mask:

Gateway

ID:

Password

192.168.001.247

255.255.255.000

192.168.001.250

admin

*******

©2021 Broadcast Electronics



4.3.3

RECEIVER FIELDS & MENU TREE

The Receiver Menu is structured similar to the Transmitter Menu. Many of the field details have

already been described in the Transmitter section and may not be listed here. Some field numbers

may be listed again when additional or separate information is provided.

35

Figure 6 - Receiver Menu Tree

©2021 Broadcast Electronics

36

•

•

•

•

•

•

OPERATION MENUS

Field #02: Receiver Frequency

Rx #0 232.500MHz

t=-01.7kHz F= -52dBm

This display shows the frequency, the tuning of the received signal (T) in kHz with respect to the

nominal frequency within just over ± 100kHz and the field strength (F) in dB. In the absence of

received signal (Sin <-90dBm) the tuning indication is random. The signal is properly tuned when

"TUNING" is within ± 6.0 kHz.

The "Rx [N]" parameter, with N between 0 and 6 shows the frequency set for the device in the case of

the optional control function in the N + 1 system. The number 0 is the default.

FIELD

-58dBm

Field #03: Received RF Field and Muting

MUTING OFF

Here the received signal field in dBm is displayed and whether or not the muting function is active.

## |

Field #04: MPX Modulation and Reception Field

MPX / FIELD -52dBm

This field displays composite modulation (MPX) via an analog moving bar and received field strength

in dBm.

Field #04Modulation of the Multiplex Signal

MPX 75kHz +0.0dB

############ |

This field shows the actual frequency deviation of the received signal due to the whole multiplex

modulation, as shown on the corresponding transmitter field.

Note that the deviation reading is very precise with clean channel reception. However, in the

absence of received field or with very week signal, noise will affect the accuracy, which will show a

much wider deviation than actual.

Fields #05 & #06: L and R Decoded Output Levels

LEFT level - 3.0dB

RIGHT level - 4.5dB

©2021 Broadcast Electronics

L########### O |

R######### O |

37

•

•

•

•

Fields 05 & 06 are only displayed if the optional internal stereo decoder is present. Field 05 displays

the peak levels in the decoded audio signal on the left and right channel, expressed in dB relative to

75kHz deviation. Field 06 shows the same information with the analog bar meters.

Field #08: Stereo Pilot Frequency level

PILOT TONE LEVEL

DEV. 7.5kHz -20.0dB

Again, this field only displays in presence of the optional stereo decoder board. The modulation for

the 19kHz stereo pilot tone embedded in the multiplex signal, is displayed with excellent precision.

There is no need to mute the modulation or to do any special action to measure it

SETUP MENUS

Field #22: Frequency setup

FREQ. 2470.175 MHz

F= -55dBm T=+ 1.2kHz

This field sets the receiver frequency in a similar manner as in the transmitters, ( in two steps on

either side of the decimal point).. The bottom line shows the associated received field and center

tuning.

The frequency changing is in real time, except in a major frequency changes which will lag for a few

second in the bottom line..

•

Field #24: LF Output Level setup

LF out lev. + 2.5dBm

Nom. level: + 6.0dBm

The Main LF outputs, either the Multiplex (MPX) and Mono signals are set simultaneous in this field.

The first row displays the actual level in dBm, while in the bottom row displays and sets the nominal

output level referenced to 75kHz deviation. The range is -1.5 to +12dBm

Field #25: Receiver Muting setup

MUTING SETUP

LEVEL: -75DB / OFF

©2021 Broadcast Electronics

38

In this field, the user may vary the insertion level of the muting circuit and its intervention. Suitable

levels are -70 to -80dBm for stereo signals and -85 to -90dBm for mono signals, depending on the

received signal strength. The muting level is unrelated to the field alarm level which may be set

differently by its own menu (see alarm setup, menu #33)

By setting "ON" or "OFF", the muting circuit may be enabled or disabled either by "mistuning alarm"

or remote control function.

•

DEEMPHASIS TIME CST

Field #26: De-emphasis setup

75 μS

DEEMPHASIS ON / OFF

MONO: 0N STEREO: ON

μ

This field sets the de-emphasis time-constant between 0, 25, 50 and 75

maybe separately set for the mono and the stereo outputs, if the stereo decoded is present

s. The de-emphasis function

•

Field #28: Optional Boards Detection

OPTIONS:

STEREO DECODER: NO

In these fields, the software detection of optional internal boards are displayed and depending on

option, setups may be made in the equipment. The stereo decoder board is the most common main

option in the receiver; while other boards may be added in the future or are available in other bands.

Depending on the options detected, additional windows will display in the setup branch in sequence

in front of Field #29 “Display Contrast”.

©2021 Broadcast Electronics

Field #33: Alarm setup and display

As in the transmitter this field displays the various alarms that sum up to the general alarm signal,

and allow some changes to them. The following table lists the alarms for the receiver:

39

•

•

•

•

•

•

•

•

•

•

•

•

•

•

ON

ON

ON/OFF

ON/OFF

ALARM SETUP

TEMPERATURE:

PLL UNLOCK:

LOW RF INPUT:

MISTUNING:

NO MODULATION: ON/OFF

OVERMODULATION: ON/OFF

HIGH TEMPERAT.: 55°C

LOW RF INPUT: -xxdBm

NO MOD. LEV.:-15.9dB

NO MOD. TIME: 90sec

UNLOCK TIME:

60sec

PIN 6: AUDIO MUTING

REMOTE LOCK

Outputs:

PIN 2: MODULATION OK

REMOTE LOCKED

PIN 7: ALARM

FIELD GOOD

PIN 3, 8: FIELD GOOD

ALARM

Field #34: I/O pin allocation and logic level setup

As described in the proper section, there are at least 4 I/O lines which may be associated to

corresponding pins of the parallel remote I/O connector on the rear panel. This submenu permits to

Inputs:

choose the corresponding function to associate to the pins with the following options

The factory default is the first line for each pin. All of these lines may be preset active high or low in

the same menu.

©2021 Broadcast Electronics

40

•

•

•

Field #36 Left & Right Level

LEFT & RIGHT LEVEL

Nom: 60.9% + 6.0dBm

This field displays based on the advance stereo decoder card option detected. With this option, it is

possible to vary the output level of the stereo signal on the decoded rear outputs in steps equal to or

less than 0.1 dB over almost the entire range between -8.4 and +12.0 dBm. The percentage does not

refer to the output level but to the position of the internal electronic attenuator which has 256 steps.

Field #37 Headphone Volume

HEADPHONE VOLUME

======= 08

Currently, Fields #36 and #37 are in the control software only. When the advanced stereo decoder

card and the relative headphone output are detected, the relative output level or volume can be

varied from here. Again, the variation is logarithmic for a more constant variation effect for each step

of the control. There are 16 steps of 3 dB each for a dynamic range of 45 dB between about 0.5 and j

100mW on a 16 Ohm headphone.

Field #39 Serial Number

SERIAL NUMBER

__R20–9-515

This field is factory set displays at the end of the Setup Branch.

©2021 Broadcast Electronics

41

SERVICE & CHASSIS DIAGRAMS

Service and repair is limited to the overall mechanical and module interconnect wiring of the GTX

and GRX. The following diagrams are provided for module and sub assembly identification of

replacement modules if needed and the units cannot be returned to the factory for service.

©2021 Broadcast Electronics

42

Transmitter Drawings

5.1.1

GTX Mechanical Layout – VHF & UHF Models

Figure 7 – Transmitter Mechanical - VHF & UHF Models

©2021 Broadcast Electronics



Receiver Drawings

5.2.1

GRX Mechanical Layout – VHF & UHF Models

Figure 8 – Receiver Layout - VHF & UHF

©2021 Broadcast Electronics

43



 

 

 

 

 

 

 

 

 

 

BEI Electronics, LLC Model GTX900 FCC ID: DDE-GTX900 IC: 131A-GTX900 Support: 217.224.9617 bdcast.com/support

 

 

:fl!llllll !!!!!!!!I! Broadcast Electronics 4100 North 24 Street, Quincy, Dlinois 62305 USA Phone

(217) 224-9600 Fax (217) 224-9607 www.bdcastcom bdcast@bdcast.com

September 23, 2021 RE: REQUEST FOR PERMISSIVE CHANGE TO FCC ID:

DDE-GTX900 Dear Madam or Sir, We are requesting designator emission hardware or a permissive 256KF8E. software changes The original omission to the product in nature was made. original grant was clerical since the change to grant FCC ID: DDE-GTX900 for the addition of and there have been no Perry Priest y Chief Operating Officer, BEi Electronics,

 

 

Broadcast Electronics Inc. 4100 North 24th Street, Quincy, Illinois 62305 USA Phone (217) 224-9600 Fax (217) 224-9607 www.bdcast.com bdcast@bdcast.com September 22, 2021 Timco Engineering, Inc. 849 N.W. State Road 45 P.O. Box 370 Newberry, FL 32669 SUBJECT: Application(s) for Certification for FCC ID: DDE-GTX900 IC: 131A-GTX900 To Whom It May Concern:

We, the undersigned, hereby authorize Sharon Hoffman at TIMCO ENGINEERING, INC. on our behalf, to apply for certification on our equipment referenced above. Any and all acts carried out by TIMCO ENGINEERING, INC. on our behalf shall have the same effect as acts of our own. This is to advise that we are in full compliance with the Anti- Drug Abuse Act. We, the applicant, are not subject to a denial of federal benefits pursuant to Section 5301 of the Anti-Drug Act of 1988, 21 USC853a, and no party to the application is subject to a denial of federal benefits pursuant to that section. Regards, Perry Priestly, Chief Operating Officer Broadcast Electronics, BEI Inc.

 

 

 

 

 

 

 

 

 

 

Broadcast Electronics 4100 North 24th Street, Quincy, Illinois 62305 USA Phone (217) 224-9600 Fax (217) 224-9607 www.bdcast.com bdcast@bdcast.com April 26, 2021 Subject: Confidentiality Request for: DDE-GTX900 / 131A-GTX900 Pursuant to FCC 47 CRF 0.457(d) and 0.459 and IC RSP-100, Section 10, the applicant requests that a part of the subject FCC application be held confidential. Type of Confidentiality Requested Short Term Short Term Short Term Short Term Short Term Short Term Short Term Short Term Short Term Permanent Permanent Permanent Permanent Permanent Permanent Permanent Exhibit Block Diagrams External Photos Internal Photos Operation Description/Theory of Operation Parts List & Placement/BOM Tuning Procedure Schematics Test Setup Photos Users Manual Having the subject information easily available to competition would negate the advantage they have achieved by developing this product. Not protecting the details of the design will result in financial hardship. Permanent Confidentiality:

The applicant requests the exhibits listed above as permanently confidential be permanently withheld from public review due to materials that contain trade secrets and proprietary information not customarily released to the public. Short-Term Confidentiality:

The applicant requests the exhibits selected above as short term confidential be withheld from public view for a period of 90 days from the date of the Grant of Equipment Authorization and prior to marketing. This is to avoid premature release of sensitive information prior to marketing or release of the product to the public. Applicant is also aware that they are responsible to notify TIMCO ENGINEERING, INC. in the event information regarding the product or the product is made available to the public. TIMCO ELECTRONIC ENGINEERING, INC. will then release the documents listed above for public disclosure pursuant to FCC Public Notice DA 04-1705. The applicant understands that until such time that IC distinguishes between Short Term and Permanent Confidentiality, either type of marked exhibit above will simply be marked Confidential when submitted to IC. Sincerely, ___________________________ Perry Priestley, Chief Operating Officer BEI Electronics, LLC