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  The Motorola®
GTX Index Page

Compiled By Robert W. Meister WA1MIK
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The GTX is a series of Motorola handheld and mobile radios that were marketing-positioned as entry-level units. The next steps up were the Saber handhelds and the Spectra mobiles, both of which have their own pages at this web site.

The GTX series is fairly unique in that they were made for 800 MHz and 900 MHz only, while the Maxtrac series that were made about the same time were available in five different bands from 30 through 900 MHz. Make sure you check the 4th character of the model number for the proper band: 800 = 'U', 900 = 'W'. Don't end up with the wrong frequency range.

GTX radios transmit and receive signals that are 5 kHz wide on 800 MHz. On 900 MHz, the bandwidth is only 2.5 kHz. This can NOT be changed in software. There's no "switch" or any mode-specific setting. You might be able to increase the transmit modulation level by adjusting the radio and/or modifying it. The receiver's bandwidth is controlled by small bandpass filters that are not easily replaced.

GTX radios come in both mobile and handheld versions. The mobiles are either 12-15 watts or 30-35 watts. The handhelds all run around 3 watts.

GTX handheld radios are either "basic" (no display or keypad on the front) or "standard" (with display and keypad on the front). All GTX mobile radios have a display.

GTX radios are sold as either Privacy Plus (PP) or LTR. These are slightly different trunking system formats and as far as amateur use is concerned, it doesn't really matter which radio you have. One of the benefits of either format is that you can't listen in on (or monitor) other conversations not intended for you. Conventional channels are NOT private.

The LCS2000 and LTS2000 are sexier-looking versions of the GTX mobile and handheld radios, respectively. The older service manuals covered these models; the newer ones do not. Naturally, they also use different programming software.

It seems that many of the part numbers for GTX products are No Longer Available (NLA) and have been replaced with newer numbers. If you need parts for a GTX radio, call Motorola Parts ID and get the updated part number before panicking.

The GTX Model Number String

The model number will be found on a sticker underneath mobile radios or on the rear of handheld radios behind the battery. It is always 12 characters in length, but the descriptions are broken up into two tables to fit the web page. The tables contain all possible values for both handheld and mobile radios.

A typical model number for a 900 MHz P/P handheld radio with display and keypad is H11WCD4CB1AN.
A typical model number for a 900 MHz 12-watt P/P mobile radio is M11WGD4CB1AN.

First six characters:

Unit TypeSeriesRangeBandPower [1]Package [3]
H=HandheldAlways 10=LCS/LTSU=800 MHz C=3 Watt [2]C=No Display
M=Mobile 1=GTXW=900 MHzG=12-15 Watt D=With Display
    R=30-35 WattH=???
NOTES:
[1]: 800 MHz radios are rated for 15 or 35 watts; 900 MHz radios are rated for 12 or 30 watts. Talk-around power is about 20% less.
[2]: Only handheld radios operate at 3 watts.
[3]: All mobile radios have a display and are thus the 'D' package.

Second six characters:

SpacingOperationSystem Feature LevelHardware
Version
Variation
4=12.5 kHzC=TrunkedB=P/P1=BasicA Usually N Usually
 D=SmartNetU=LTR5=Standard  
The "Variation" column describes how the radio was originally packaged or shipped, and with what accessory kit. More information on the "Figuring out what you have" page.

Programming

These radios are programmed with a personal computer, a RIB, and a standard Motorola modular programming cable. If are you are unfamiliar with Motorola radio programming, you should read An overview of the Motorola Radio Service Software (RSS) by Mike Morris WA6ILQ, as well as Introduction to RSS and Radio Programming by Robert Meister WA1MIK.

Information Articles and PDFs

. GTX Radio Overview and Common Information by Robert W. Meister WA1MIK
Read this article first, then choose one of the next two for specific info.
. GTX Mobile-Specific Information by Robert W. Meister WA1MIK
. GTX Handheld-Specific Information by Robert W. Meister WA1MIK
. Secrets of the GTX Model Definition File by Robert W. Meister WA1MIK
A more detailed explanation of the MDF layout.
. Manual Power Control for the GTX 12-watt radio by Robert W. Meister WA1MIK
This simple modification fixes a major problem with transmitter output power.
. Modifying a GTX Mobile Radio for Remote Head Operation by Robert Schulz KC6UDS
An off-site link to an article that describes how to remove the control head from the radio, make an extension cable, and mount the head remotely.
. GTX Mobile Radio High/Low Power Modification for use with an external amplifier by Sean Magowan VE2NRG
Sean wanted to use a GTX to power an external amplifer. These modifications let him choose high or low power and key the external amp only when set for low power. This is a nice combination and was well thought out.
. Product Service Bulletin F-485 - DTMF Tone Distortion and Power Down Problems 21kB PDF file provided by Mike Morris WA6ILQ
. GTX Mobile Radio User's Guide 170kB PDF file
. GTX Mobile Parts and Accessories 310kB PDF file
. GTX Handheld Radio User's Guide 1.4MB PDF file
. GTX Handheld Parts and Accessories 430kB PDF file
. GTX LTR Mobile Radio Spec Sheet 290kB PDF file
. GTX Privacy-Plus Mobile Radio Spec Sheet 70kB PDF file
. GTX LTR Handheld Radio Sales Brochure 620kB PDF file
. GTX PP Handheld Radio Sales Brochure 600kB PDF file
. LCS2000 Mobile Radio Spec Sheet 100kB PDF file
. LTS2000 Handheld Radio Spec Sheet 50kB PDF file
. GTX/LTS2000 Handheld Radio Service Manual Part 1 of 3 (6802945C75-A) 1.4MB PDF file, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Service Manual Part 2 of 3 (6802945C75-A) 500kB PDF file, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Service Manual Part 3 of 3 (6802945C75-A) 1.5MB PDF file, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Service Manual Part 1 of 3 (6802948C90) 375kB PDF file, newer than the above, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Service Manual Part 2 of 3 (6802948C90) 176kB PDF file, newer than the above, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Service Manual Part 3 of 3 (6802948C90) 1.3MB PDF file, newer than the above, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Service Manual Revision (IMR414) 1.1MB PDF file, provided by Mike Morris WA6ILQ
. GTX/LTS2000 Handheld Radio Mutual Approval Accessories Manual Supplement (6802947C35-E) 189kB PDF file, provided by Mike Morris WA6ILQ
. GTX/LTR RSS Manual (6802948C70-B) 331kB PDF file, provided by Mike Morris WA6ILQ
. GTX/LTR Mobile Service Manual (6880906Z18) 2.1MB PDF file, provided by Mike Morris WA6ILQ


Motorola, GTX, Privacy Plus, and a whole lot of other terms are trademarks of Motorola Inc.

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This page originally posted 03-Dec-07.



Article text, photographs, and hand-coded HTML © Copyright 2007 By Robert W. Meister WA1MIK.
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This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.