Back to Home
GTX Index Page
Maintained By Robert W. Meister WA1MIK
|
Up one level (Moto index) Back to Home |
The Motorola® GTX Index Page Maintained By Robert W. Meister WA1MIK |
|
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.
800 MHz GTX radios transmit and receive signals that are 5 kHz wide. 900 MHz GTX radios transmit and receive signals that are 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 handheld and mobile versions. The handhelds all run around 3 watts. The mobiles are either 12-15 watts or 30-35 watts. The antenna connector is a Mini UHF female and very easy to break if you use an adapter and use stiff coax like RG213. A Mini UHF male to UHF or N female pigtail is a requirement. The pigtail relieves the stress on the radio connector.
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. One of the benefits of either format is that you can't listen in on (or monitor) other conversations not intended for you. These are slightly different trunking system formats and as far as amateur conventional analog use is concerned, it doesn't really matter which radio you have. 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 Type | Series | Range | Band | Power [1] | Package [3] |
|---|---|---|---|---|---|
| H=Handheld | Always 1 | 0=LCS/LTS | U=800 MHz | C=3 Watt [2] | C=No Display |
| M=Mobile | 1=GTX | W=900 MHz | G=12-15 Watt | D=With Display | |
| R=30-35 Watt | H=??? |
Second six characters:
| Spacing | Operation | System | Feature Level | Hardware Version |
Variation |
|---|---|---|---|---|---|
| 4=12.5 kHz | C=Trunked | B=P/P | 1=Basic | A Usually | N Usually |
| D=SmartNet | U=LTR | 5=Standard |
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 and Modification Articles
 |
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 offsite 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. |
Guides, Manuals, and other PDF files
Motorola, GTX, Privacy Plus, and a whole lot of other terms are trademarks of Motorola Inc.
Mike Morris WA6ILQ provided all of the service manuals and revisions.
Back to the top of the page
Up one level (Moto index)
Back to Home
This page originally posted 03-Dec-07.
Article text, photographs, and hand-coded HTML
© Copyright 2007 By Robert W. Meister WA1MIK.
See the Contact Information on this site's main index page.
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.