| Up one level (Motorola index) Back to Home | Using the Motorola GR1225 as a Repeater By Don L. Blanchard - WA7GTU IRLP Node 3574 Edited and HTML'd by Mike Morris WA6ILQ |
- Motorola Gr1225 Repeater Manual Instructions
- Motorola Gr1225 Repeater Manual Uniden
- Motorola Gr1225 Repeater Manual User
- Motorola Gr1225 Uhf Repeater Manual
Note from the editor:
The R1225 is a continuous duty radio (about the size of a MaxTrac) that has two antenna connectors and will work in full duplex mode, and 25w continuous duty at that! The GR1225 is that radio in a box with a power supply plus two options: a duplexer and an advanced controller (the sales brochure is here). The GR1225 was designed to be the continuous duty model in the the GR300 / 400 / 500 line of prepackaged repeaters, all of which were intended for low-duty-cycle full duplex applications like a shopping mall security department repeater, or other low-end non-public-safety repeating applications. The GR1225 configuration parameters allow it to be programmed as a repeater or as a non-repeating full duplex radio and that, coupled with the continuous duty design makes it ideal as a point to point link, and much better than a Maxtrac or GM300 mobile, neither of which can duplex, or run continouous duty. The R1225 / GR1225 also has a fairly decent internal controller where the GR300 / 400 / 500 series required the RICK box to do that. The optional advanced controller could be one of four, and an autopatch was available (see the sales brochure link above).
The Internet Repeater Linking Project is a worldwide informal group of amateur radio repeaters that are linked using VoIP (Voice over Internet Protocol) systems. More information on IRLP is available at http://www.irlp.net. Each repeater in the IRLP network is connected to the internet through a PC running the IRLP system program, with runs on the Linux operating system. The computer is treated as if it was a link radio, with audio in, audio out (via the sound card), COR and PTT (via pins in the printer port). The IRLP interface board that plugs into the printer port has the necessary interfacing circuitry, including a hardware touchtone decoder. The board can be jumpered for simplex or full duplex operation, and if you have a full duplex environment you really want to set the jumper to match. A 'Node' in the IRLP system is one computer and repeater system.
Repeater Transceiver Specifications 5164 M03GRC Mode Duty t cap MHz 343 min. Standby) switchable tbs. Continuo @ 300 1000 2.6 Ad Ade I-IOW m) Vac as-sow 12. S Ade IOW ppm dgm kHz -65 -80 co 50/ 4 5 cap Tra FM FCC Receiver spur ppm to rated go (rms Watts with kHz -go dB 20/26/30 kHz -80 dB -go da 22 S s 300 to 3000. Repeater Builder. Acces PDF Radius Gr1225 Repeater Manual KE4MU REPEATER BUILD GR1225 AND PI REPEATER 2XHow to Build a Simplex Repeater Here is the Wiring for the Motorola R1225 to Zum 1.0/Arduino Due by, Bruce Given VE2GZI MMDVM Motorola Maxtrac radio rear 16 pin hack! Surplus Radio Guide Series, Programming Motorola Maxtrac u0026 Radius models gr1225. Manuals & Books; Material Handling. Motorola Mcs2000 Model I 800 Mhz Motorola Radius M120 Gm300 M1225 160 Ch 750 Uhf Motorola Msf5000 Repeater Motorola Mtr2000. The R1225 service manual covers the R1225 (repeater module), GR1225 (desktop repeater) and RKR1225 (rackmount repeater) as all of them have the R1225 radio in them. As far as the 403 error, may be a regional site block.
The ideal IRLP situation is where you have an internet connection at the repeater site and can connect the node computer to the repeater controller directly (as if it was a second radio). Since very few repeater sites have an internet connection many connections use the second-best option: a point-to-point radio link (on UHF, 900 MHz or 1200 MHz link frequencies) between the repeater site and a location where the node computer and internet connection is actually located. Others use the third-best option: they set up the node computer and radio as if it was just another user on the repeater.
This article describes how WA7GTU set up a Motorola GR1225 radio as a local repeater, with an IRLP node connected to it. The same GR1225 if programmed differently could also function as a 'ground level' end of a point-to-point link, i.e. set up as a non-repeating full duplex base station.
There are pages at this web site that cover the RSS and RIB in detail.
IRLP Node 3574, located in Cedar City, Utah has been operating with a Motorola Radius GR1125 Repeater on the 444.900 ‑ 449.900 MHz frequency pair for a couple of years. There have been a number of inquiries as to how it was interfaced with requests to make the information available on the Internet. The following document is an attempt to answer those inquiries. It is believed that the mobile GM300 is basically the same radio and the following information should apply to both models, however the GR1225 will run full duplex, whereas the GM300 is a 'normal' PTT radio.
There are several models of the GR1225, and the product line includes models that cover both the 146 to 174 MHz and 444 to 474 MHz frequency ranges with differing power levels. The 146-174 models can be 'stretched' down to 145 MHz, and the 444-474 models can be stretched to 440 MHz.
The first thing that you need to know is that the GR1225 has to be programmed using the appropriate Motorola RSS software, so you either need to know someone with the hardware/software or have good rapport with your local Motorola dealer. The hardware/software is of fairly old vintage and hopefully it is still available in your area. The radio programming software is DOS based and will not even work on today's faster computers. The programming is done through the microphone plug with a computer interface called a RIB. There are diagrams of these interfaces on the Internet, but getting the software is a problem. Please see the RSS page in the Motorola section at this web site for details. The second thing that you need to know is that the 450 MHz version of the GR1225 will program no lower than 444.000 MHz without modification. The 3574 node repeater is operating within this frequency range, so no attempt was made to look into what modification would be required to go lower in frequency, but it probably can be done.
The GR1225 is a small self contained repeater (see photo below) that can be programmed to 16 different frequencies. The 3574 node repeater is also programmed to a second frequency of 444.500 - 449.500 MHz which is another frequency pair coordinated for this area. The built in duplexer handles this second frequency reasonably well with very little degradation, but this frequency is only there as a backup and adding it to the programming took less than a minute. The repeater operates from a built in switching power supply and there is a fan integrated into the housing for cooling. It often operates for hours at a time and there have had no temperature problems. The fan is temperature controlled and does not come on very often. The model in operation is a 10 watts version. The author also has an older 25 watt version as a spare, but has not yet tried it on IRLP. It is all programmed, but some of the connections on the Accessory Connector need to be rewired.
Below is a reproduced page from the GR1225 Service Manual explaining a bit about the available connections in the accessory connector on the rear of the radio. The fuctions of a number of the pins are programmable.
|
As mentioned above, a number of the accessory plug pins can be programmed for various functions. Several are electrically bidirectional but are programmed as either in or out. The manual says that Pin #8 defaults to COR, but on mine it was not, so that function had to be programmed in addition to the operating frequencies, PL, timeout timer, and identifier parameters (callsign and 10 minute spacing). The repeater also came with an existing interconnect cable and all that was required was to move two of the pins in the accessory plug and put the connectors required to interface with the IRLP board on the other end. See the Expanded Accessory Chart below.
The table below is from section four of the June, 1997 version of the R1225 manual, part number 6880905Z53-O.
Section 4 General
|
The call sign identifier for IRLP can be programmed via software in the IRLP box, but this wasn't adequately researched prior to getting the radio programmed, so for node 3574 it is programmed into the radio itself. There is one inherent problem with using the built in radio identifier and that is if the repeater is keyed up before the identifier completes its cycle, it will start over again when the repeater is un-keyed. This is usually not a problem locally, but it is a problem when it is connected to a reflector and there is not a sufficient pause between transmissions for the identifier to drop out. Programming the call for higher speed helps in this case. There is also a programmable transmitter timeout timer which is currently set to 3 minutes and it gets timed out on occasion. A little longer time period might be preferable.
In my system the GR1225 Carrier Delay set to Off. This means that if you 'key up' you will not get a response back unless the identifier comes on. Our PL is set to 100 Hz. The use of PL on IRLP is HIGHLY recommended.
Just remember that if you need to make any changes to the configuration of the radio (i.e. the programming), it means another trip back to whomever has the RIB (the programming hardware) and the Radio Service Software (RSS), so try to get it right the first time. The author has a good relationship with the local Motorola dealer and was fortunate enough to wind up with a complete set of service manuals for the GR1225, but does not have the required software, progamming box or cable for programming the radio. If you end up with a GR1225 the two manuals that you will need are 6880905Z53 (the R1225 radio) and 6880904Z90 (the GR1225 cabinet, power supply, etc). The Radio Service Software has its own manual.
The figure below illustrates how the GR1225 repeater is interconnected to the Version 3.0 IRLP Board. Note that the IRLP board has its own DTMF decoder and the audio feed from the radio goes to both the computer LINE IN connection and also to the IRLP board pin 8.
If you are connecting a GR1225 to a Version 2 IRLP board you will need to use the two diagrams below to identify the changes. Note that NOTHING in the pinouts is the same between the two versions.
|
A final note, please do not request copies of the Service Manuals from the author. Many of the schematics are very large and with both books the stack is about 3/4 of an inch thick. Pretty much all of what you need to know is in the information above.
Don L. Blanchard - WA7GTU - Nov. 2006
Three notes from WA6ILQ on the GR1225 units:
- The R1225 is a 16 channel radio. Adding the local 'test pair' to the channel list takes an extra minute as you are programming it, and depending on your circumstances might be a good idea.
- The stock GR1225 power supply is the HPN90333A and is made by Duracomm. It is a switching supply and weighs about six pounds. The output is 13.8 volts at 15 amps continuous and 17 amps intermittent duty. The optional HLN9455A Battery Revert Kit adds a power fail/switchover/battery charger module that connects a user-supplied sealed battery to the unit, keeps it charged, and switches to it during a power failure. Don't bother buying one, just get the schematic for it and build it yourself.
- One of the options in a GR1225 is an internal duplexer (part number RFE4000A, made by Celwave as their part number 633-2A-2N). It is a notch-only duplexer.The HKN9235 Internal Duplexer Cable Kit (about $40 from Motorola Parts) consists of two cables that have N-type male connectors on the duplexer end and mini-UHF male connectors on the radio end. The cables that Moto supplies are not fabricated to meet any technical requirement (i.e. length), they are simply made long enough to fit with only a little slack.
The cheap plain-jane RG-58/U cable used in the HKN9235 Internal Duplexer Cable Kit causes some serious desense - more than 2 dB, in fact. RG-58/U coax is just too leaky to be used for duplexer jumper cables of any type.
If you are ordering a GR1225, forget the duplexer. Pick one up off of eBay and make up your own cables, using only double-shielded RG-400/U cable, and install the correct silver-plated connectors on each end - and without any adapters.
Back to the top of the page
Up one level (Motorola index page)
Back to Home
This page originally posted on 21-Nov-2006
Photos and article text text © Copyright November 2006 by Don L. Blanchard, WA7GTU
Artistic layout and hand-coded HTML © Copyright 2006 and date of last update by Mike Morris WA6ILQ.
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.
| Up one level Back to Home | The Motorola MaxTrac, Radius, GM300, DeskTrac, GR-series Index page Maintained By Robert Meister WA1MIK This page has undergone a major reorganization. Everything is all still here; items just got moved. Use your browser's SEARCH function to find things, as they're now sorted better. |
Attention Ebay buyers and sellers: If you are buying or selling a MaxTrac, Radius mobile, or GM300 you need to read the warning on this page.
Any Motorola prices mentioned on this page (or on any page at this web site) should be taken only as a rough guideline. Motorola adjusts prices quarterly, and offers one set of prices to their dealers/service shops (the so called 'NSO' Pricing ('National Service Organization')), another to 'self-maintaining' fleet customers (i.e. those that have their own radio shops.. cities, counties, police departments, fire departments, etc) and a third on their telephone order desk (i.e. retail sales to the public). Prices are changed quarterly, so use the mentioned prices only as a rough indication. If you encounter a large price change on anything where we've mentioned a price we'd appreciate an emailed update.
Radio Modification and Descriptive Articles:
Caution: A lot of the information in the articles below is valid only for MaxTracs and MaxTrac-based Radius radios (the Radius mobiles that have the letters LRA in the middle of the model number). The MaxTracs came first, then when Motorola needed radios to sell as Radius models (i.e. retail sales products) they changed the label and the firmware. There are some very slight differences, but there is a lot of commonality between the hardware (the circuit boards, etc) inside the MaxTrac and Radius LRA series mobiles.
The later GM300 series (which includes the Radius M10, M120 and M130 radios) look a lot like the MaxTrac and Radius LRA series, have similar specifications and physical construction, but are actually quite different internally. The GM300 series do not respond well to being blanked by the MaxTrac Lab RSS. There is no Radius or GM300 series Lab RSS floating around (yet) so unsuspecting experimenters can turn one of these radios into an expensive brick if not careful. See the GM300 article below for more details.
Astron makes a power supply for the MaxTrac / Radius LRA / GM300 series that has a sleeve on the top that the radio slides into. The SL-11-RRA supplies 13.8V at 11 amps. Click here for a photo.
Note that the MaxTrac / Radius / GM300 radios have a 10% transmit duty cycle and that translates to 10 seconds of transmit and 90 seconds of receive, or 30 seconds of transmit and 4.5 minutes of receive. This is definitely not repeater service or any kind of amateur radio service that I'm familiar with! And besides, the rear mounted heat sink does not cool the pin diodes or any other PC-board mounted components. Reducing the transmit power can help, but some models have a minimum rated power level (like not less than 25 watts and not more than 45 watts). In other words, the MaxTrac, Radius and GM300 are nowhere near the conservatively rated and over-heat-sinked designs of the MICOR, Syntor or Mitrek era radios.
| Introductory Information on the MaxTrac, Radius and GM300 series radios, the DeskTrac station, and the GR300, GR400, GR500, GR1225, R1225 and RKR1225 series repeaters Compiled by Mike Morris WA6ILQ An introduction to the Motorola radios covered by this section, with background, history, some model-specific information, photos, and lots of miscellaneous tidbits such as mic jack or antenna connector replacement. You should read this article before any of the other articles here. |
| An Introduction to the MaxTrac or Radius M100 / M214 / M216 Firmware, Logic Boards and RF Boards By Neil Johnson WBØEMU What your radio can do depends a lot on what version firmware you have in which logic board mated to which RF board. |
| Identifying the five most common Radius models By Bob DeMattia K1IW Some front panel images with text that describes the major differences. |
| MaxTrac Logic Board Jumpers and Connectors By Robert Meister WA1MIK Locations and explanations of the three-pin jumpers on MaxTrac and Radius logic boards, as well as the signals on the three multi-pin connectors. |
| The Definitive Guide to the 16 pin MaxTrac and Radius Option Connector By Neil Johnson WBØEMU Not every output pin or input pin is equal.. Some are more equal than others.. |
| Transmitter Spurious Outputs when runat less than rated power By Robert Meister WA1MIK The myth about running radios at less than rated output power: confirmed, plausible or busted? The author does some simple experiments and analysis. |
| That annoying 'cli-click' when the PTT button is released By Robert Meister WA1MIK Some radios do it, some don't. The author traced the source and shows severalways to get rid of it. |
| Microphone Hang-upMechanisms By Robert Meister WA1MIK A primer on hang-up buttons found on MaxTrac mikes, but the same schemes areused by a lot of other Motorola radios, and some similar schemes are even usedon radios made by other manufacturers. |
| Self-Quieting Frequencies Compiled by Robert Meister WA1MIK GM300, MaxTrac, Radius, and MaraTrac mobile radios all share designs and components, so they all suffer from this problem. Here's a collection of frequencies that these radios can generate internally; some of them can be annoying. |
Model-Specific Articles:
| Overview of the DeskTrac Station By Robert Meister WA1MIK Model numbers, connectors, interface signals, front panel overview, photographs. A lot of the information came from the DeskTrac Service Manual. |
| Information about the GM300-series radios By Robert Meister WA1MIK Specs, board numbers, accessory plugs, how they differ from MaxTracs. |
| MaxTrac VHF, UHF, and 800 MHz radio models By the Repeater-Builder Staff Information taken directly from the 'No Longer Available' detailed service manual. |
| MaxTrac 900 MHz radio models By Repeater-Builder Staff Information taken directly from the 'No Longer Available' service manuals. |
| Radius M100, M206, M208, M214, M216 radio models and board info Compiled by Robert W. Meister WA1MIK Information extracted from the Radius Service Manual (of course NLA). |
| A reproduction of the MaxTrac Performance Specifications 20KB PDF file |
| MaxTrac initialization programmingchoices By Robert Meister WA1MIK A follow-up to the article below that details the once-only screen fields you must fill in when initializing a radio. |
| Hex-editing the 900 MHz MaxTrac MDF file by Robert Meister WA1MIK This article describes the process that you have to do so you can easily program your MaxTrac on amateur 900 MHz frequencies. You can find it in the Motorola RSS and RIB articles section of this web site. |
| MaxTrac Secrets By Robert Meister WA1MIK Communications, code plug, and other internal data secrets of the MaxTrac-series radios. |
| How the MaxTrac Controls Transmit Power and Deviation By Robert Meister WA1MIK An explanation of why the radio has weird transmit power and deviation on amateur frequencies and what you can do about it. Applies to GM300, Radius, and MaraTrac radios too. |
| Ham-friendly Firmware Mods for the MaxTrac By Robert Meister WA1MIK What to change in the firmware to deal with out-of-band operation. A follow-up to the article above. Applies to Radius and MaraTrac radios too. |
| How to replace the firmware and what to align for the MaxTrac By Robert Meister WA1MIK The procedure to replace the firmware chip and what needs to be realigned when doing so. A follow-up to the article above. Applies to Radius and MaraTrac radios too. |
| MaxTrac Adjustments By Robert Meister WA1MIK More than you ever wanted to know about the various pots and coils on the RF boards of the MaxTrac-series radios, and how to adjust them. Of course Motorola doesn't want you to twiddle with these, but occasionally it's necessary. |
| Replacing the Dallas Memory Module In the MaxTrac or Radius By Scott Withrow KC9LQV Radios that use the Dallas NVRAM will be losing their memory when the battery goes dead. They have about a 20 year lifetime, so any radio made prior to about 1992 will have this problem and the Dallas chip will need to be replaced. This article tells you what to do about it. |
Some additional GM300 information is available from Colin Lowe G1IVG at http://www.g1ivg.com/motgm300.htm (offsite link).
Motorola Gr1225 Repeater Manual Instructions
Interfacing Articles:
Motorola Gr1225 Repeater Manual Uniden
| Repeater controller interfacing - with photos By Scott Lichtsinn KBØNLY With information on connections to radios with both 16-pin and 5-pin logic boards. |
| Simple Repeater Interfacing forMaxTrac / Radius / GM300 Radios By Robert Meister WA1MIK A very simple procedure with all the details needed to interface these radios to most repeater controllers. This is a companion article to the ones above and below. |
| Repeater Interface for two radios 207 kB PDF Using a ID-O-Matic II kit, by Dale NØXAS, that has both a CW ID and a Time-Out/hang timer to make a repeater using MaxTrac, Radius, GM300, or CDM-series mobile radios. |
| Using a MaxTrac / Radius / GM300 Mobile Radio as a CW Beacon Transmitter By Robert Meister WA1MIK The HamGadgets ID-O-Matic had all the features necessary for this task. It was just a matter of finding a way to transmit real on/off CW rather than modulated audio CW for beacon use. Should also work with the MaraTrac radios. |
| Using Remote Channel Select on a 16-channel GM300 radio By Robert Meister WA1MIK A transcription of a PDF file with additional information that explains the wiring and radio configuration you need to remotely select channels on the 16-channel GM300 radio. This won't work on the 8-channel GM300 because the firmware won't allow you to reprogram the accessory connector pins for this purpose. |
Modification and Repair Articles:
| Diagnosing, Troubleshooting, and Repairing MaxTrac Radios By Robert Meister WA1MIK Hints and helpful suggestions for repairing MaxTrac, Radius, and GM300 mobile radios. |
| Disassembling the GM300 Mobile Radios By Robert Meister WA1MIK If your GM300 is way off frequency, this is usually caused by dirty interconnect pins between the logic board and the RF board. You'll need to take it completely apart to clean them. Here's a procedure for doing it. |
| Narrow-band conversion kits for the GM300-series radios By Robert Meister WA1MIK Transcribed from the official document that can be found elsewhere on this site. |
| Adding additional channels to the GM300 By Thomas M. Mayse, KN5S If your GM300 has the expanded logic board it can have as many as 40 channels. Moto learned their lesson on the 32-channel MaxTrac and artificially limited GM300 to 16 channels so that they could force anyone needing more than 16 into a Spectra. Tom walks you through the process with a step-by-step procedure. |
| Upgrading a MaxTrac or Radius M100 / M214 / M216 to 32 channels - with photos By Scott Lichtsinn KBØNLY A step-by-step procedure that will upgrade any MaxTrac (except the 2-channel ones) to 16 or 32 channels (depending on which logic board you have), with options like scan. |
| Additional Notes on MaxTrac or Radius M100 / M214 / M216 Logic Boards By Scott Lichtsinn KBØNLY This article goes with the 'Upgrading' article above. It has additional notes including a procedure for converting a trunking logic board to conventional. |
| Moving a 449-470 MHz MaxTrac to cover the 440-450 MHz Amateur band - with photos By Scott Lichtsinn KBØNLY A step-by-step procedure that makes a UHF MaxTrac a lot more useful on 440-450 MHz. |
| Manual Power Control of the MaxTrac PA deck By Robert Meister WA1MIK When a MaxTrac (on any band) is run out of it's designed frequency range the power control routines in the firmware get confused. Unfortunately the confusion causes the radio to run the PA deck wide open, which can burn it up. This writeup gives a workaround. |
| Volume Control Replacement By Robert Meister WA1MIK If you have a MaxTrac, Radius LRA or GM300 series radio that runs at full volume all the time, or either turning the volume control has no effect or causes a huge jump in volume, then you have a broken volume control (a common problem). It's a simple, inexpensive fix and this writeup walks you through the repair. |
| Volume Control Replacement UPDATE By Robert Meister WA1MIK The original and new Motorola pots are No Longer Available but an alternate part can be purchased for about the same price that does the job quite well. |
| A Squelch Mod for the MaxTrac / GM300 / M120 By Barry Sloan VE6SBS Barry's web siteOriginal offsite article This simple mod minimizes the squelch tail duration - a useful feature on consistently strong signals (such as on point-to-point links). And if you want, you can add a switch to make the modification selectable at will. Just add a toggle switch in series with the lead of the capacitor. |
| Converting an 800 MHz talkaround MaxTrac to a 902 MHz Repeater Receiver By Robert Meister WA1MIK An 800 MHz MaxTrac mobile with the talk-around option makes a good 902 MHz link, control or repeater receiver. This writeup walks you through the process. |
| Converting Other 800 MHz MaxTracs to the 900 MHz Ham Band By Robert Meister WA1MIK A continuation of the above article based on followup information. |
| Replacing the front-end filters in 800 and 900 MHz MaxTracs By Robert Meister WA1MIK This article describes how to cleanly remove and install new front-end filters in these radios. A companion article to the ones above and below. |
| Extending the MaxTrac 900 MHz VCO Frequency Range By Robert Meister WA1MIK andDavid Malicki, N1OFJ How to move the 900 MHz MaxTrac VCO down to 902 MHz. |
| Getting the MaxTrac 900 MHz radio to fully cover 902-928 MHz By Robert Meister WA1MIK An expansion of the articles above and below, with detailed analysis. Also shows a way of adding a manual deviation control if your radio needs it. |
| Changing the MaxTrac 900 MHz VCO switch point By Robert Meister WA1MIK The MaxTrac 900 MHz radio's VCO has two ranges. This article explains why, and shows how to change the frequency where the range is switched. This will extend the useful operating range of the transmitter. |
| Converting a 900 MHz MaxTrac from Trunking to Conventional operation By Robert Meister WA1MIK Replacing the firmware, blanking the board, and complete initialization steps. |
| Converting a 900 MHz MaxTrac from Trunking to Conventional operation - An Alternate Method By Greg Stahlman KJ6KO This article assumes that you have read the article above first. |
| Converting a 146-174 MaxTrac or Radius to 220 MHz By Matt Krick, K3MK Yes, you CAN move a VHF MaxTrac or Radius LRA to 220 MHz, complete with direct frequency entry in the RSS. This is NOT a beginners project, it requires serious surgery, access to a milling machine, and is best done to a radio that has a blown up PA deck. |
| Converting a low-band MaxTrac to Six Meter Operation By Robert Meister WA1MIK All of the steps necessary to make a 42-50 MHz radio operate in the 46-54 MHz range. Two radios were converted; the trials and tribulations, plus the results, are summarized here. |
| The Ontario Hydro Low-band MaxTrac 99-Channel Conversion By Robert Meister WA1MIK Documentation and procedure for converting a 42-50 MHz low-band radio. |
| Permanently Disabling the Extender on a Low-band MaxTrac Radio By Robert Meister WA1MIK A simple jumper disables the noise blanker. This is necessary for radios that will be used as base station or repeater receivers. |
| MaxTrac Transmit PL Mute Circuit By Robert Meister WA1MIK A simple circuit that immediately mutes the transmit PL tone. Especially helpful on radios that don't have a 16-pin accessory jack. |
| Converting a MaxTrac 146-174 MHz radio to 136-162 MHz for APRS use By Robert Meister WA1MIK Some MaxTracs work on 144.39 MHz; others do not. Bob analyzed the radio's performance on both range splits and tells you what needs to be done to improve operation below 146 MHz. This was suggested by Scott KBØNLY who modified a bunch of radios in his area for APRS. |
| Getting a Line Output signal from a MaxTrac radio By Robert Meister WA1MIK Often, MaxTracs are used to monitor police and fire calls in garages and fire departments. These are usually noisy environments and amplifiers and loudspeakers are installed to boost the signal. As always, there are multiple methods of interfacing to MaxTracs, but by far the hardest unit to use is the one with the 5-pin accessory jack. Here's a fairly painless way to get the desired signal out of such a radio. Step-by-step instructions are provided so even a technician who's unfamiliar with the radio can make it work. |
| Adding a Flat TX Audio Input to a 5-pin MaxTrac or Radius By Robert Meister WA1MIK Only the radios with 16-pin logic boards have a flat TX audio input. Three extra components give you the same functionality on 5-pin logic boards. |
| Getting Discriminator Audio from a 5-pin MaxTrac radio by Scott Withrow, KC9LQV MaxTrac and Radius mobiles with 5-pin accessory jacks are often overlooked because they lack signals such as discriminator (flat) receiver audio. Scott duplicated the circuitry from a 16-pin radio and added it to his 5-pin radio to get flat audio out of it. This article shows what he did. |
| Why the receive audio is lower on some MaxTracs than others by Robert Meister WA1MIK Analysis of the circuit and component value measurements solve this mystery. |
| Maxdroid: Add a digital display and front-panel frequency selection to VHF/UHF MaxTrac transceivers By Avinoam Albo, 4X1HF (offsite link) |
Manuals and Documentation: If anybody wants to contribute additional part numbers (or even manual scans) we will post them.
| FLN6433B MOSCAD Adapter for MaxTrac and GM300 68 kB PDF file Drawn by Eric Lemmon WB6FLY The RJ45 pin numbering is identical to the MIC jack convention used on those radios. | ||||||||||
| FLN6746B IRRINET Adapter for MaxTrac and GM300 64 kB PDF file Drawn by Eric Lemmon WB6FLY The RJ45 pin numbering is identical to the MIC jack convention used on those radios. | ||||||||||
| TLN5277E DC Power Line Filter Kit 214 kB PDF This is the alternator whine filter that Moto sells you for the MaxTrac, Radius, GM300, CDM series mobile radios. | ||||||||||
| GM300 User Manual 6880902Z09 1.37 MB PDF file Early version manual, covers both 8 and 16 channel units. | ||||||||||
| GM300 8-Channel Quick User Guide 6880902Z26-A 56.6 kB PDF file | ||||||||||
| GM300 16-Channel Quick User Guide 6880902Z41-B 58.3 kB PDF file | ||||||||||
| GM300 Accessories Brochure 743 kB PDF file | ||||||||||
| GM300 Radio Service Software Manual 6880902Z36-B 2 MB PDF file | ||||||||||
| GM300 Detailed Service Manual 6880902Z32, was about $13 (No Longer Available as of June 2007) This service manual covers the GMC and GMR models of the GM300 radio. This is another one you want on your shelf. You occasionally see these on popular auction sites. Note that this manual is not as well-organized as the MaxTrac Service Manual.
| ||||||||||
| GR300 and GR500 Service Manual 6880903Z42-A 9.31 MB PDF This manual covers: a) the GR300 and GR500 housings, b) the fan assemblies, c) the power supplies (GR300=HPN8393, built by Astron and GR500=HPN9005, built by StarWerks), d) the HLN3948 Basic Controller, the HLN8389 Zetron ZR320 ('Selective Calling Repeater Controller'), the HLN8390 Zetron ZR330 ('Remote Telephone Interface'), the HLN9119 Zetron ZR340 ('Tone Remote Adapter Repeater Controller'), the HLN9004 Instrument Associates i50R ('Basic Interconnect RepeaterController') and HLN9121 TRA100R ('Advanced Interconnect Repeater Controller'). There is also some info in this manual about the R*I*C*K controller. This manual does not cover the HLN9447 Instrument Associates i20R, the HLN9120 i750R or the HLN8388 Zetron ZR310 (community repeater controller), however the ZR310 service manual is available for download from the Zetron page at this web site. There are two manuals that cover the i20R: The Service Manual 6880904Z40 and the Programming Manual 6880904Z55. As of March 2012 both are still in print and being sold by Motorola Parts. The Service Manual costs about $26, and theSoftware Manual costs about $32. And you will still need the i20R RSS, which is HVN9085. The i750 used HVN9084 and cable HLN9102A. | ||||||||||
| GR300 and GR500 Controller Programming Manual 6880903Z43-A 5.51 MB PDF This manual covers the programming of the HLN3948 Basic Controller, the HLN8389 Zetron ZR320 ('Selective Calling Repeater Controller'), the HLN8390 Zetron ZR330 ('Remote Telephone Interface'), the HLN9119 Zetron ZR340 ('Tone Remote Adapter Repeater Controller'), the HLN9004 Instrument Associates i50R ('Basic Interconnect Repeater Controller') and HLN9121 TRA100R ('Advanced Interconnect Repeater Controller'). There is also some info in this manual about the R*I*C*K controller. | ||||||||||
| GR400 and GR500 X-Pand Repeater Service Manual 6880905Z54-O 50 MB PDF This manual also contains SMRs for the HPN9005 and HPN9041 power supplies (schematics), and Troubleshooting for External Controllers. | ||||||||||
| GR400 X-Pand Repeaters Battery Revert Accessory HLN9455 1.6 MB PDF file | ||||||||||
| MaxTrac 100 and 300 User Manual 6880901Z04 389 kB PDF file | ||||||||||
| MaxTrac Detailed Service Manual 6880102W84, was about $30 but is no longer available (NLA). This is the low band, high band, UHF, and 800 MHz MaxTrac service manual that covers the MGA, MJA, MQA, MWA and AHA models. If you ever pop a cover on any of those models then you want this book on your shelf; it's chock full of good stuff. You occasionally see these books on eBay and the other auction sites.
| ||||||||||
| MaxTrac 900 MHz Service Manual 6802980G40 7.7 MB PDF. This is the 900 MHz MaxTrac Conventional service manual (the 900 MHz MaxTrac trunked radio service manual is part number 6802977G10). This manual deals with the 12w radios. It also has the info on the HMN1038A desk microphone and the HLN5309A 'Desk Tray' - the plastic base station stand that holds the radio in a comfortable position for use. If you have the 30 watt radio you need the supplement below. Other than the test modes, this manual covers the trunking models as well. You occasionally see these manuals on eBay and other auction sites. By popular demand, this manual was donated by Bob WA1MIK and scanned by Eric WB6FLY. | ||||||||||
| MaxTrac 900 MHz 30 watt Power Amplifier Supplement IMR200 597 kB PDF. This is the 30 watt Power Amplifier Instruction Manual Revision (supplement) that came with a 6802977G10 Trunking Service Manual. It applies to conventional radios as well; the only difference is the firmware and front panel escutcheon. Note that the 30w model is rated for 30w on 896-902 MHz (i.e. the repeater input range) but only 20w on the talk-around / simplex 935-941 MHz range. This manual was donated by Bob WA1MIK and scanned by Eric WB6FLY. | ||||||||||
| Changing a Radio's Personality Section 3 from a MaxTrac RSS manual 45 kB PDF This is close enough to be used for the GM300 and even the MaraTrac. | ||||||||||
| Programming Advanced Features Section 4 from a MaxTrac RSS manual 177 kB PDF This is close enough to be used for the GM300. | ||||||||||
| Alignment and Calibration Section 5 from a MaxTrac RSS manual 206 kB PDF This is close enough to be used for the GM300 and some applies to the MaraTrac. | ||||||||||
| Radius (GM300) M10 User Manual 6880903Z05 1.34 MB PDF file | ||||||||||
| Radius (GM300) M10 Service Manual 6880903Z03, about $28. This covers the XVC series of radios, a single-channel Radius GM300 that uses the 8-channel masked logic board. | ||||||||||
| User's 'cheat sheet' for the Radius (GM300) M10, M120 and M130 6880902Z96. Save your money, if you have an IQ higher than that of egg white, you don't need this. | ||||||||||
| Radius (GM300) M120 User Manual 6880902Z97 1.33 MB PDF file | ||||||||||
| Radius (GM300) M120 Service Manual 6880902Z98-O 7 MB PDF Donated by Eric Lemmon WB6FLY This is a 2-channel Radius GM300 that uses the 8-channel masked logic board. The manual includes revisions MMR-077, MMR-100, and MMR-104. | ||||||||||
| Radius (GM300) M130 User Manual 6880903Z64 1.29 MB PDF file | ||||||||||
| Radius (GM300) M130 Service Manual 6880903Z65, about $30. This is a 2-channel Radius GM300 that uses the 16-channel expanded logic board. | ||||||||||
| Radius M100, M208 and M216 User Manual (early) 6880901Z47 770 kB PDF file While the title page says M100 and M200, there never was a M200 model.. this book covers the M100, M208 and M216. The later book is 6880900Z45. The M206 became the M208. The M214 became the M216. | ||||||||||
| Radius M100, M206, M208, M214 and M216 VHF / UHF / 800 Service Manual 6880101W58-A 7.55 MB PDF This manual was about $45 when it was available and is the manual that covers all of the Radius LRA series except for the low band and 403-430 MHz radios. Low band and low range UHF were added in the revisions. I've never seen a 900 MHz Radius LRA. A large number of the board diagrams and service section of this manual are the same as the MaxTrac Detailed Service Manual. You need to include all of the Instruction Manual Revisions below into the manual. All of them include revised model tables.
| ||||||||||
| Radius R1225 Transceiver Service Manual 6880905Z53-O 57.7 MB PDF file This is the radio that's used in the GR1225, GR400, and GR500 X-Pand repeaters. The manual also contains several SMRs. | ||||||||||
| Radius RKR1225 Rack Mount Repeater Service Manual 6880907Z10-O 15.7 MB PDF file This repeater uses the R1225 transceiver. | ||||||||||
| Instrument Associates was bought out by GAI-Tronics Corp. Reading, PA. They are at 800-492-1212. |
Parts Catalogs:
| The MaxTrac Parts Catalog 2.2 MB PDF file |
| Another MaxTrac Parts Catalog 200 kB PDF file |
| A Radius M10 / M110 / M120 Parts Catalog 200 kB PDF file |
| A Radius M208 / M216 Parts Catalog 200 kB PDF file |
| The Radius GM300 Parts Catalog 200 kB PDF file |
Back to the top of the page
Up one level (Moto index)
Back to Home
This page originally posted 05-Jan-2005
The GR1225 is a small self contained repeater (see photo below) that can be programmed to 16 different frequencies. The 3574 node repeater is also programmed to a second frequency of 444.500 - 449.500 MHz which is another frequency pair coordinated for this area. The built in duplexer handles this second frequency reasonably well with very little degradation, but this frequency is only there as a backup and adding it to the programming took less than a minute. The repeater operates from a built in switching power supply and there is a fan integrated into the housing for cooling. It often operates for hours at a time and there have had no temperature problems. The fan is temperature controlled and does not come on very often. The model in operation is a 10 watts version. The author also has an older 25 watt version as a spare, but has not yet tried it on IRLP. It is all programmed, but some of the connections on the Accessory Connector need to be rewired.
Below is a reproduced page from the GR1225 Service Manual explaining a bit about the available connections in the accessory connector on the rear of the radio. The fuctions of a number of the pins are programmable.
|
As mentioned above, a number of the accessory plug pins can be programmed for various functions. Several are electrically bidirectional but are programmed as either in or out. The manual says that Pin #8 defaults to COR, but on mine it was not, so that function had to be programmed in addition to the operating frequencies, PL, timeout timer, and identifier parameters (callsign and 10 minute spacing). The repeater also came with an existing interconnect cable and all that was required was to move two of the pins in the accessory plug and put the connectors required to interface with the IRLP board on the other end. See the Expanded Accessory Chart below.
The table below is from section four of the June, 1997 version of the R1225 manual, part number 6880905Z53-O.
Section 4 General
|
The call sign identifier for IRLP can be programmed via software in the IRLP box, but this wasn't adequately researched prior to getting the radio programmed, so for node 3574 it is programmed into the radio itself. There is one inherent problem with using the built in radio identifier and that is if the repeater is keyed up before the identifier completes its cycle, it will start over again when the repeater is un-keyed. This is usually not a problem locally, but it is a problem when it is connected to a reflector and there is not a sufficient pause between transmissions for the identifier to drop out. Programming the call for higher speed helps in this case. There is also a programmable transmitter timeout timer which is currently set to 3 minutes and it gets timed out on occasion. A little longer time period might be preferable.
In my system the GR1225 Carrier Delay set to Off. This means that if you 'key up' you will not get a response back unless the identifier comes on. Our PL is set to 100 Hz. The use of PL on IRLP is HIGHLY recommended.
Just remember that if you need to make any changes to the configuration of the radio (i.e. the programming), it means another trip back to whomever has the RIB (the programming hardware) and the Radio Service Software (RSS), so try to get it right the first time. The author has a good relationship with the local Motorola dealer and was fortunate enough to wind up with a complete set of service manuals for the GR1225, but does not have the required software, progamming box or cable for programming the radio. If you end up with a GR1225 the two manuals that you will need are 6880905Z53 (the R1225 radio) and 6880904Z90 (the GR1225 cabinet, power supply, etc). The Radio Service Software has its own manual.
The figure below illustrates how the GR1225 repeater is interconnected to the Version 3.0 IRLP Board. Note that the IRLP board has its own DTMF decoder and the audio feed from the radio goes to both the computer LINE IN connection and also to the IRLP board pin 8.
If you are connecting a GR1225 to a Version 2 IRLP board you will need to use the two diagrams below to identify the changes. Note that NOTHING in the pinouts is the same between the two versions.
|
A final note, please do not request copies of the Service Manuals from the author. Many of the schematics are very large and with both books the stack is about 3/4 of an inch thick. Pretty much all of what you need to know is in the information above.
Don L. Blanchard - WA7GTU - Nov. 2006
Three notes from WA6ILQ on the GR1225 units:
- The R1225 is a 16 channel radio. Adding the local 'test pair' to the channel list takes an extra minute as you are programming it, and depending on your circumstances might be a good idea.
- The stock GR1225 power supply is the HPN90333A and is made by Duracomm. It is a switching supply and weighs about six pounds. The output is 13.8 volts at 15 amps continuous and 17 amps intermittent duty. The optional HLN9455A Battery Revert Kit adds a power fail/switchover/battery charger module that connects a user-supplied sealed battery to the unit, keeps it charged, and switches to it during a power failure. Don't bother buying one, just get the schematic for it and build it yourself.
- One of the options in a GR1225 is an internal duplexer (part number RFE4000A, made by Celwave as their part number 633-2A-2N). It is a notch-only duplexer.The HKN9235 Internal Duplexer Cable Kit (about $40 from Motorola Parts) consists of two cables that have N-type male connectors on the duplexer end and mini-UHF male connectors on the radio end. The cables that Moto supplies are not fabricated to meet any technical requirement (i.e. length), they are simply made long enough to fit with only a little slack.
The cheap plain-jane RG-58/U cable used in the HKN9235 Internal Duplexer Cable Kit causes some serious desense - more than 2 dB, in fact. RG-58/U coax is just too leaky to be used for duplexer jumper cables of any type.
If you are ordering a GR1225, forget the duplexer. Pick one up off of eBay and make up your own cables, using only double-shielded RG-400/U cable, and install the correct silver-plated connectors on each end - and without any adapters.
Back to the top of the page
Up one level (Motorola index page)
Back to Home
This page originally posted on 21-Nov-2006
Photos and article text text © Copyright November 2006 by Don L. Blanchard, WA7GTU
Artistic layout and hand-coded HTML © Copyright 2006 and date of last update by Mike Morris WA6ILQ.
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.
| Up one level Back to Home | The Motorola MaxTrac, Radius, GM300, DeskTrac, GR-series Index page Maintained By Robert Meister WA1MIK This page has undergone a major reorganization. Everything is all still here; items just got moved. Use your browser's SEARCH function to find things, as they're now sorted better. |
Attention Ebay buyers and sellers: If you are buying or selling a MaxTrac, Radius mobile, or GM300 you need to read the warning on this page.
Any Motorola prices mentioned on this page (or on any page at this web site) should be taken only as a rough guideline. Motorola adjusts prices quarterly, and offers one set of prices to their dealers/service shops (the so called 'NSO' Pricing ('National Service Organization')), another to 'self-maintaining' fleet customers (i.e. those that have their own radio shops.. cities, counties, police departments, fire departments, etc) and a third on their telephone order desk (i.e. retail sales to the public). Prices are changed quarterly, so use the mentioned prices only as a rough indication. If you encounter a large price change on anything where we've mentioned a price we'd appreciate an emailed update.
Radio Modification and Descriptive Articles:
Caution: A lot of the information in the articles below is valid only for MaxTracs and MaxTrac-based Radius radios (the Radius mobiles that have the letters LRA in the middle of the model number). The MaxTracs came first, then when Motorola needed radios to sell as Radius models (i.e. retail sales products) they changed the label and the firmware. There are some very slight differences, but there is a lot of commonality between the hardware (the circuit boards, etc) inside the MaxTrac and Radius LRA series mobiles.
The later GM300 series (which includes the Radius M10, M120 and M130 radios) look a lot like the MaxTrac and Radius LRA series, have similar specifications and physical construction, but are actually quite different internally. The GM300 series do not respond well to being blanked by the MaxTrac Lab RSS. There is no Radius or GM300 series Lab RSS floating around (yet) so unsuspecting experimenters can turn one of these radios into an expensive brick if not careful. See the GM300 article below for more details.
Astron makes a power supply for the MaxTrac / Radius LRA / GM300 series that has a sleeve on the top that the radio slides into. The SL-11-RRA supplies 13.8V at 11 amps. Click here for a photo.
Note that the MaxTrac / Radius / GM300 radios have a 10% transmit duty cycle and that translates to 10 seconds of transmit and 90 seconds of receive, or 30 seconds of transmit and 4.5 minutes of receive. This is definitely not repeater service or any kind of amateur radio service that I'm familiar with! And besides, the rear mounted heat sink does not cool the pin diodes or any other PC-board mounted components. Reducing the transmit power can help, but some models have a minimum rated power level (like not less than 25 watts and not more than 45 watts). In other words, the MaxTrac, Radius and GM300 are nowhere near the conservatively rated and over-heat-sinked designs of the MICOR, Syntor or Mitrek era radios.
| Introductory Information on the MaxTrac, Radius and GM300 series radios, the DeskTrac station, and the GR300, GR400, GR500, GR1225, R1225 and RKR1225 series repeaters Compiled by Mike Morris WA6ILQ An introduction to the Motorola radios covered by this section, with background, history, some model-specific information, photos, and lots of miscellaneous tidbits such as mic jack or antenna connector replacement. You should read this article before any of the other articles here. |
| An Introduction to the MaxTrac or Radius M100 / M214 / M216 Firmware, Logic Boards and RF Boards By Neil Johnson WBØEMU What your radio can do depends a lot on what version firmware you have in which logic board mated to which RF board. |
| Identifying the five most common Radius models By Bob DeMattia K1IW Some front panel images with text that describes the major differences. |
| MaxTrac Logic Board Jumpers and Connectors By Robert Meister WA1MIK Locations and explanations of the three-pin jumpers on MaxTrac and Radius logic boards, as well as the signals on the three multi-pin connectors. |
| The Definitive Guide to the 16 pin MaxTrac and Radius Option Connector By Neil Johnson WBØEMU Not every output pin or input pin is equal.. Some are more equal than others.. |
| Transmitter Spurious Outputs when runat less than rated power By Robert Meister WA1MIK The myth about running radios at less than rated output power: confirmed, plausible or busted? The author does some simple experiments and analysis. |
| That annoying 'cli-click' when the PTT button is released By Robert Meister WA1MIK Some radios do it, some don't. The author traced the source and shows severalways to get rid of it. |
| Microphone Hang-upMechanisms By Robert Meister WA1MIK A primer on hang-up buttons found on MaxTrac mikes, but the same schemes areused by a lot of other Motorola radios, and some similar schemes are even usedon radios made by other manufacturers. |
| Self-Quieting Frequencies Compiled by Robert Meister WA1MIK GM300, MaxTrac, Radius, and MaraTrac mobile radios all share designs and components, so they all suffer from this problem. Here's a collection of frequencies that these radios can generate internally; some of them can be annoying. |
Model-Specific Articles:
| Overview of the DeskTrac Station By Robert Meister WA1MIK Model numbers, connectors, interface signals, front panel overview, photographs. A lot of the information came from the DeskTrac Service Manual. |
| Information about the GM300-series radios By Robert Meister WA1MIK Specs, board numbers, accessory plugs, how they differ from MaxTracs. |
| MaxTrac VHF, UHF, and 800 MHz radio models By the Repeater-Builder Staff Information taken directly from the 'No Longer Available' detailed service manual. |
| MaxTrac 900 MHz radio models By Repeater-Builder Staff Information taken directly from the 'No Longer Available' service manuals. |
| Radius M100, M206, M208, M214, M216 radio models and board info Compiled by Robert W. Meister WA1MIK Information extracted from the Radius Service Manual (of course NLA). |
| A reproduction of the MaxTrac Performance Specifications 20KB PDF file |
| MaxTrac initialization programmingchoices By Robert Meister WA1MIK A follow-up to the article below that details the once-only screen fields you must fill in when initializing a radio. |
| Hex-editing the 900 MHz MaxTrac MDF file by Robert Meister WA1MIK This article describes the process that you have to do so you can easily program your MaxTrac on amateur 900 MHz frequencies. You can find it in the Motorola RSS and RIB articles section of this web site. |
| MaxTrac Secrets By Robert Meister WA1MIK Communications, code plug, and other internal data secrets of the MaxTrac-series radios. |
| How the MaxTrac Controls Transmit Power and Deviation By Robert Meister WA1MIK An explanation of why the radio has weird transmit power and deviation on amateur frequencies and what you can do about it. Applies to GM300, Radius, and MaraTrac radios too. |
| Ham-friendly Firmware Mods for the MaxTrac By Robert Meister WA1MIK What to change in the firmware to deal with out-of-band operation. A follow-up to the article above. Applies to Radius and MaraTrac radios too. |
| How to replace the firmware and what to align for the MaxTrac By Robert Meister WA1MIK The procedure to replace the firmware chip and what needs to be realigned when doing so. A follow-up to the article above. Applies to Radius and MaraTrac radios too. |
| MaxTrac Adjustments By Robert Meister WA1MIK More than you ever wanted to know about the various pots and coils on the RF boards of the MaxTrac-series radios, and how to adjust them. Of course Motorola doesn't want you to twiddle with these, but occasionally it's necessary. |
| Replacing the Dallas Memory Module In the MaxTrac or Radius By Scott Withrow KC9LQV Radios that use the Dallas NVRAM will be losing their memory when the battery goes dead. They have about a 20 year lifetime, so any radio made prior to about 1992 will have this problem and the Dallas chip will need to be replaced. This article tells you what to do about it. |
Some additional GM300 information is available from Colin Lowe G1IVG at http://www.g1ivg.com/motgm300.htm (offsite link).
Motorola Gr1225 Repeater Manual Instructions
Interfacing Articles:
Motorola Gr1225 Repeater Manual Uniden
| Repeater controller interfacing - with photos By Scott Lichtsinn KBØNLY With information on connections to radios with both 16-pin and 5-pin logic boards. |
| Simple Repeater Interfacing forMaxTrac / Radius / GM300 Radios By Robert Meister WA1MIK A very simple procedure with all the details needed to interface these radios to most repeater controllers. This is a companion article to the ones above and below. |
| Repeater Interface for two radios 207 kB PDF Using a ID-O-Matic II kit, by Dale NØXAS, that has both a CW ID and a Time-Out/hang timer to make a repeater using MaxTrac, Radius, GM300, or CDM-series mobile radios. |
| Using a MaxTrac / Radius / GM300 Mobile Radio as a CW Beacon Transmitter By Robert Meister WA1MIK The HamGadgets ID-O-Matic had all the features necessary for this task. It was just a matter of finding a way to transmit real on/off CW rather than modulated audio CW for beacon use. Should also work with the MaraTrac radios. |
| Using Remote Channel Select on a 16-channel GM300 radio By Robert Meister WA1MIK A transcription of a PDF file with additional information that explains the wiring and radio configuration you need to remotely select channels on the 16-channel GM300 radio. This won't work on the 8-channel GM300 because the firmware won't allow you to reprogram the accessory connector pins for this purpose. |
Modification and Repair Articles:
| Diagnosing, Troubleshooting, and Repairing MaxTrac Radios By Robert Meister WA1MIK Hints and helpful suggestions for repairing MaxTrac, Radius, and GM300 mobile radios. |
| Disassembling the GM300 Mobile Radios By Robert Meister WA1MIK If your GM300 is way off frequency, this is usually caused by dirty interconnect pins between the logic board and the RF board. You'll need to take it completely apart to clean them. Here's a procedure for doing it. |
| Narrow-band conversion kits for the GM300-series radios By Robert Meister WA1MIK Transcribed from the official document that can be found elsewhere on this site. |
| Adding additional channels to the GM300 By Thomas M. Mayse, KN5S If your GM300 has the expanded logic board it can have as many as 40 channels. Moto learned their lesson on the 32-channel MaxTrac and artificially limited GM300 to 16 channels so that they could force anyone needing more than 16 into a Spectra. Tom walks you through the process with a step-by-step procedure. |
| Upgrading a MaxTrac or Radius M100 / M214 / M216 to 32 channels - with photos By Scott Lichtsinn KBØNLY A step-by-step procedure that will upgrade any MaxTrac (except the 2-channel ones) to 16 or 32 channels (depending on which logic board you have), with options like scan. |
| Additional Notes on MaxTrac or Radius M100 / M214 / M216 Logic Boards By Scott Lichtsinn KBØNLY This article goes with the 'Upgrading' article above. It has additional notes including a procedure for converting a trunking logic board to conventional. |
| Moving a 449-470 MHz MaxTrac to cover the 440-450 MHz Amateur band - with photos By Scott Lichtsinn KBØNLY A step-by-step procedure that makes a UHF MaxTrac a lot more useful on 440-450 MHz. |
| Manual Power Control of the MaxTrac PA deck By Robert Meister WA1MIK When a MaxTrac (on any band) is run out of it's designed frequency range the power control routines in the firmware get confused. Unfortunately the confusion causes the radio to run the PA deck wide open, which can burn it up. This writeup gives a workaround. |
| Volume Control Replacement By Robert Meister WA1MIK If you have a MaxTrac, Radius LRA or GM300 series radio that runs at full volume all the time, or either turning the volume control has no effect or causes a huge jump in volume, then you have a broken volume control (a common problem). It's a simple, inexpensive fix and this writeup walks you through the repair. |
| Volume Control Replacement UPDATE By Robert Meister WA1MIK The original and new Motorola pots are No Longer Available but an alternate part can be purchased for about the same price that does the job quite well. |
| A Squelch Mod for the MaxTrac / GM300 / M120 By Barry Sloan VE6SBS Barry's web siteOriginal offsite article This simple mod minimizes the squelch tail duration - a useful feature on consistently strong signals (such as on point-to-point links). And if you want, you can add a switch to make the modification selectable at will. Just add a toggle switch in series with the lead of the capacitor. |
| Converting an 800 MHz talkaround MaxTrac to a 902 MHz Repeater Receiver By Robert Meister WA1MIK An 800 MHz MaxTrac mobile with the talk-around option makes a good 902 MHz link, control or repeater receiver. This writeup walks you through the process. |
| Converting Other 800 MHz MaxTracs to the 900 MHz Ham Band By Robert Meister WA1MIK A continuation of the above article based on followup information. |
| Replacing the front-end filters in 800 and 900 MHz MaxTracs By Robert Meister WA1MIK This article describes how to cleanly remove and install new front-end filters in these radios. A companion article to the ones above and below. |
| Extending the MaxTrac 900 MHz VCO Frequency Range By Robert Meister WA1MIK andDavid Malicki, N1OFJ How to move the 900 MHz MaxTrac VCO down to 902 MHz. |
| Getting the MaxTrac 900 MHz radio to fully cover 902-928 MHz By Robert Meister WA1MIK An expansion of the articles above and below, with detailed analysis. Also shows a way of adding a manual deviation control if your radio needs it. |
| Changing the MaxTrac 900 MHz VCO switch point By Robert Meister WA1MIK The MaxTrac 900 MHz radio's VCO has two ranges. This article explains why, and shows how to change the frequency where the range is switched. This will extend the useful operating range of the transmitter. |
| Converting a 900 MHz MaxTrac from Trunking to Conventional operation By Robert Meister WA1MIK Replacing the firmware, blanking the board, and complete initialization steps. |
| Converting a 900 MHz MaxTrac from Trunking to Conventional operation - An Alternate Method By Greg Stahlman KJ6KO This article assumes that you have read the article above first. |
| Converting a 146-174 MaxTrac or Radius to 220 MHz By Matt Krick, K3MK Yes, you CAN move a VHF MaxTrac or Radius LRA to 220 MHz, complete with direct frequency entry in the RSS. This is NOT a beginners project, it requires serious surgery, access to a milling machine, and is best done to a radio that has a blown up PA deck. |
| Converting a low-band MaxTrac to Six Meter Operation By Robert Meister WA1MIK All of the steps necessary to make a 42-50 MHz radio operate in the 46-54 MHz range. Two radios were converted; the trials and tribulations, plus the results, are summarized here. |
| The Ontario Hydro Low-band MaxTrac 99-Channel Conversion By Robert Meister WA1MIK Documentation and procedure for converting a 42-50 MHz low-band radio. |
| Permanently Disabling the Extender on a Low-band MaxTrac Radio By Robert Meister WA1MIK A simple jumper disables the noise blanker. This is necessary for radios that will be used as base station or repeater receivers. |
| MaxTrac Transmit PL Mute Circuit By Robert Meister WA1MIK A simple circuit that immediately mutes the transmit PL tone. Especially helpful on radios that don't have a 16-pin accessory jack. |
| Converting a MaxTrac 146-174 MHz radio to 136-162 MHz for APRS use By Robert Meister WA1MIK Some MaxTracs work on 144.39 MHz; others do not. Bob analyzed the radio's performance on both range splits and tells you what needs to be done to improve operation below 146 MHz. This was suggested by Scott KBØNLY who modified a bunch of radios in his area for APRS. |
| Getting a Line Output signal from a MaxTrac radio By Robert Meister WA1MIK Often, MaxTracs are used to monitor police and fire calls in garages and fire departments. These are usually noisy environments and amplifiers and loudspeakers are installed to boost the signal. As always, there are multiple methods of interfacing to MaxTracs, but by far the hardest unit to use is the one with the 5-pin accessory jack. Here's a fairly painless way to get the desired signal out of such a radio. Step-by-step instructions are provided so even a technician who's unfamiliar with the radio can make it work. |
| Adding a Flat TX Audio Input to a 5-pin MaxTrac or Radius By Robert Meister WA1MIK Only the radios with 16-pin logic boards have a flat TX audio input. Three extra components give you the same functionality on 5-pin logic boards. |
| Getting Discriminator Audio from a 5-pin MaxTrac radio by Scott Withrow, KC9LQV MaxTrac and Radius mobiles with 5-pin accessory jacks are often overlooked because they lack signals such as discriminator (flat) receiver audio. Scott duplicated the circuitry from a 16-pin radio and added it to his 5-pin radio to get flat audio out of it. This article shows what he did. |
| Why the receive audio is lower on some MaxTracs than others by Robert Meister WA1MIK Analysis of the circuit and component value measurements solve this mystery. |
| Maxdroid: Add a digital display and front-panel frequency selection to VHF/UHF MaxTrac transceivers By Avinoam Albo, 4X1HF (offsite link) |
Manuals and Documentation: If anybody wants to contribute additional part numbers (or even manual scans) we will post them.
| FLN6433B MOSCAD Adapter for MaxTrac and GM300 68 kB PDF file Drawn by Eric Lemmon WB6FLY The RJ45 pin numbering is identical to the MIC jack convention used on those radios. | ||||||||||
| FLN6746B IRRINET Adapter for MaxTrac and GM300 64 kB PDF file Drawn by Eric Lemmon WB6FLY The RJ45 pin numbering is identical to the MIC jack convention used on those radios. | ||||||||||
| TLN5277E DC Power Line Filter Kit 214 kB PDF This is the alternator whine filter that Moto sells you for the MaxTrac, Radius, GM300, CDM series mobile radios. | ||||||||||
| GM300 User Manual 6880902Z09 1.37 MB PDF file Early version manual, covers both 8 and 16 channel units. | ||||||||||
| GM300 8-Channel Quick User Guide 6880902Z26-A 56.6 kB PDF file | ||||||||||
| GM300 16-Channel Quick User Guide 6880902Z41-B 58.3 kB PDF file | ||||||||||
| GM300 Accessories Brochure 743 kB PDF file | ||||||||||
| GM300 Radio Service Software Manual 6880902Z36-B 2 MB PDF file | ||||||||||
| GM300 Detailed Service Manual 6880902Z32, was about $13 (No Longer Available as of June 2007) This service manual covers the GMC and GMR models of the GM300 radio. This is another one you want on your shelf. You occasionally see these on popular auction sites. Note that this manual is not as well-organized as the MaxTrac Service Manual.
| ||||||||||
| GR300 and GR500 Service Manual 6880903Z42-A 9.31 MB PDF This manual covers: a) the GR300 and GR500 housings, b) the fan assemblies, c) the power supplies (GR300=HPN8393, built by Astron and GR500=HPN9005, built by StarWerks), d) the HLN3948 Basic Controller, the HLN8389 Zetron ZR320 ('Selective Calling Repeater Controller'), the HLN8390 Zetron ZR330 ('Remote Telephone Interface'), the HLN9119 Zetron ZR340 ('Tone Remote Adapter Repeater Controller'), the HLN9004 Instrument Associates i50R ('Basic Interconnect RepeaterController') and HLN9121 TRA100R ('Advanced Interconnect Repeater Controller'). There is also some info in this manual about the R*I*C*K controller. This manual does not cover the HLN9447 Instrument Associates i20R, the HLN9120 i750R or the HLN8388 Zetron ZR310 (community repeater controller), however the ZR310 service manual is available for download from the Zetron page at this web site. There are two manuals that cover the i20R: The Service Manual 6880904Z40 and the Programming Manual 6880904Z55. As of March 2012 both are still in print and being sold by Motorola Parts. The Service Manual costs about $26, and theSoftware Manual costs about $32. And you will still need the i20R RSS, which is HVN9085. The i750 used HVN9084 and cable HLN9102A. | ||||||||||
| GR300 and GR500 Controller Programming Manual 6880903Z43-A 5.51 MB PDF This manual covers the programming of the HLN3948 Basic Controller, the HLN8389 Zetron ZR320 ('Selective Calling Repeater Controller'), the HLN8390 Zetron ZR330 ('Remote Telephone Interface'), the HLN9119 Zetron ZR340 ('Tone Remote Adapter Repeater Controller'), the HLN9004 Instrument Associates i50R ('Basic Interconnect Repeater Controller') and HLN9121 TRA100R ('Advanced Interconnect Repeater Controller'). There is also some info in this manual about the R*I*C*K controller. | ||||||||||
| GR400 and GR500 X-Pand Repeater Service Manual 6880905Z54-O 50 MB PDF This manual also contains SMRs for the HPN9005 and HPN9041 power supplies (schematics), and Troubleshooting for External Controllers. | ||||||||||
| GR400 X-Pand Repeaters Battery Revert Accessory HLN9455 1.6 MB PDF file | ||||||||||
| MaxTrac 100 and 300 User Manual 6880901Z04 389 kB PDF file | ||||||||||
| MaxTrac Detailed Service Manual 6880102W84, was about $30 but is no longer available (NLA). This is the low band, high band, UHF, and 800 MHz MaxTrac service manual that covers the MGA, MJA, MQA, MWA and AHA models. If you ever pop a cover on any of those models then you want this book on your shelf; it's chock full of good stuff. You occasionally see these books on eBay and the other auction sites.
| ||||||||||
| MaxTrac 900 MHz Service Manual 6802980G40 7.7 MB PDF. This is the 900 MHz MaxTrac Conventional service manual (the 900 MHz MaxTrac trunked radio service manual is part number 6802977G10). This manual deals with the 12w radios. It also has the info on the HMN1038A desk microphone and the HLN5309A 'Desk Tray' - the plastic base station stand that holds the radio in a comfortable position for use. If you have the 30 watt radio you need the supplement below. Other than the test modes, this manual covers the trunking models as well. You occasionally see these manuals on eBay and other auction sites. By popular demand, this manual was donated by Bob WA1MIK and scanned by Eric WB6FLY. | ||||||||||
| MaxTrac 900 MHz 30 watt Power Amplifier Supplement IMR200 597 kB PDF. This is the 30 watt Power Amplifier Instruction Manual Revision (supplement) that came with a 6802977G10 Trunking Service Manual. It applies to conventional radios as well; the only difference is the firmware and front panel escutcheon. Note that the 30w model is rated for 30w on 896-902 MHz (i.e. the repeater input range) but only 20w on the talk-around / simplex 935-941 MHz range. This manual was donated by Bob WA1MIK and scanned by Eric WB6FLY. | ||||||||||
| Changing a Radio's Personality Section 3 from a MaxTrac RSS manual 45 kB PDF This is close enough to be used for the GM300 and even the MaraTrac. | ||||||||||
| Programming Advanced Features Section 4 from a MaxTrac RSS manual 177 kB PDF This is close enough to be used for the GM300. | ||||||||||
| Alignment and Calibration Section 5 from a MaxTrac RSS manual 206 kB PDF This is close enough to be used for the GM300 and some applies to the MaraTrac. | ||||||||||
| Radius (GM300) M10 User Manual 6880903Z05 1.34 MB PDF file | ||||||||||
| Radius (GM300) M10 Service Manual 6880903Z03, about $28. This covers the XVC series of radios, a single-channel Radius GM300 that uses the 8-channel masked logic board. | ||||||||||
| User's 'cheat sheet' for the Radius (GM300) M10, M120 and M130 6880902Z96. Save your money, if you have an IQ higher than that of egg white, you don't need this. | ||||||||||
| Radius (GM300) M120 User Manual 6880902Z97 1.33 MB PDF file | ||||||||||
| Radius (GM300) M120 Service Manual 6880902Z98-O 7 MB PDF Donated by Eric Lemmon WB6FLY This is a 2-channel Radius GM300 that uses the 8-channel masked logic board. The manual includes revisions MMR-077, MMR-100, and MMR-104. | ||||||||||
| Radius (GM300) M130 User Manual 6880903Z64 1.29 MB PDF file | ||||||||||
| Radius (GM300) M130 Service Manual 6880903Z65, about $30. This is a 2-channel Radius GM300 that uses the 16-channel expanded logic board. | ||||||||||
| Radius M100, M208 and M216 User Manual (early) 6880901Z47 770 kB PDF file While the title page says M100 and M200, there never was a M200 model.. this book covers the M100, M208 and M216. The later book is 6880900Z45. The M206 became the M208. The M214 became the M216. | ||||||||||
| Radius M100, M206, M208, M214 and M216 VHF / UHF / 800 Service Manual 6880101W58-A 7.55 MB PDF This manual was about $45 when it was available and is the manual that covers all of the Radius LRA series except for the low band and 403-430 MHz radios. Low band and low range UHF were added in the revisions. I've never seen a 900 MHz Radius LRA. A large number of the board diagrams and service section of this manual are the same as the MaxTrac Detailed Service Manual. You need to include all of the Instruction Manual Revisions below into the manual. All of them include revised model tables.
| ||||||||||
| Radius R1225 Transceiver Service Manual 6880905Z53-O 57.7 MB PDF file This is the radio that's used in the GR1225, GR400, and GR500 X-Pand repeaters. The manual also contains several SMRs. | ||||||||||
| Radius RKR1225 Rack Mount Repeater Service Manual 6880907Z10-O 15.7 MB PDF file This repeater uses the R1225 transceiver. | ||||||||||
| Instrument Associates was bought out by GAI-Tronics Corp. Reading, PA. They are at 800-492-1212. |
Parts Catalogs:
| The MaxTrac Parts Catalog 2.2 MB PDF file |
| Another MaxTrac Parts Catalog 200 kB PDF file |
| A Radius M10 / M110 / M120 Parts Catalog 200 kB PDF file |
| A Radius M208 / M216 Parts Catalog 200 kB PDF file |
| The Radius GM300 Parts Catalog 200 kB PDF file |
Back to the top of the page
Up one level (Moto index)
Back to Home
This page originally posted 05-Jan-2005
Credits and Acknowledgements:
MaxTrac, Radius, GM300, Spectra, GT, GTX, GR300, GR400, GR500, Hear Clear, Radio Service Software, RSS and many other names are trademarks of Motorola Inc.
Front-view photos of the two-channel and multi-channel radios at the top of the pageby Robert Meister WA1MIK.
5th edition geology glossary pdf answers. Edited text, artistic layout, and the hand-coded HTML is ©Copyright 2005 and date of last update by Mike Morris WA6ILQ.
Motorola Gr1225 Repeater Manual User
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.
Motorola Gr1225 Uhf Repeater Manual
