The Motorola CDM Mobile Radio Index page

Motorola index
Back to Home The Motorola CDM Series
Mobile Radio Index Page
And with some information on the Waris handhelds (HT750 / 1250 / 1550 series)
Originally created by Mike Morris WA6ILQ and improved upon
by Robert Meister WA1MIK (SK) with information provided by several people.
Currently Maintained by Mike Morris WA6ILQ

DONATIONS OF INFORMATION, ESPECIALLY PDFs OF MANUALS WE DON'T HAVE WOULD BE GREATLY APPRECIATED.

Comments / critiques / suggestions / corrections / updates for this page are welcome and appreciated.
(Actually for any page at this web site)

The CDM-series of mobile radios are great radios… They were introduced in 1999 and were the follow-on series to the MaxTrac / Radius / GM300 product line. The CDMs were the mobile radios in the "Professional Series" product line which also included the HT750, the HT1250, and the HT1550 handhelds and used the same CPS. The code name used in the development of the Professional Series was "Waris" and you will find references to the Waris Series on other web pages. There is a CDM model number decoder below.

Think of the Motorola CDM series as a HT750 / HT1250 / HT1550 series handheld radio repackaged as a mobile except with a very good (varactor tuned) front end on the receiver, a good power amplifier on the transmitter and a big display. They are built in a very well shielded aluminum chassis. The interior of the radio is compartmentalized and each section of the radio is fully shielded from the others by the lid which has internal dividers for each section.

Unfortunately all CDM support has been discontinued as of June 2015. Parts are limited, some are No Longer Available ("NLA"), like the custom-made (by Murata) surface mount wide band IF filters. Somewhere around 2001-2003 the CDMs were replaced in the sales book by the XPR series and the CM200, CM300 and PR400 series of mobile radios (anybody know the actual XPR or CM introduction date?).

If anyone has additional hints / tricks / gotcha's, manuals or documents on the CDM or Waris radios we'd be happy to post them… You can be credited or anonymous, your choice - please contact the page maintainer listed above.
For example, a step-by-step article on how to recover from the "EEPRM CS ERROR" situation would be useful.
Yet another example would be a step-by-step procedure to stretch the lower limit of the 450-512 MHz "S" range radios down to 440 MHz. without losing receiver sensitivity or transmitter power.
Another would be a step-by-step conversion of the "200 MHz" CDM (which was actually shipped on 217-222 MHz) to cover the amateur FM spectrum at 222-225 MHz.

Anybody have any Service / Repair Notes or Field Service Bulletins to share?

Jump to: Programming the Waris Radios Interfacing to Other Equipment Articles

Mounting DC Power Manual PDFs Accessories

Programming the Waris Radios: (the CDM mobiles and the HT750 / 1250 / 1550 series handhelds)

	The CDM radios are programmed by HVN9025 Professional Radio CPS which runs under Windows 95, 98, XP, 7 and 10. That CPS also programs these: CDM750, CDM1250, CDM1550, HT750, HT1250, HT1550, MTX, EX500, EX600, EX600XLS, PRO5150, PRO7150, PRO9150, GP320, GP340, GP360, GP380, GP318, GP338, GP640, GP680 and the GP1280. The HVN9025 CPS allows selectable wideband or narrowband on a per-channel basis. Unfortunately you cannot clone one model of handheld to another or to a mobile or a mobile to a handheld. You want to find and use Revision R06.12.05 (released in December 2011) as it is the last one that allows wide or narrow selection without a "Professional Series" wideband entitlement key. That revision also fixed a number of problems / bugs including the 64‑bit Windows USB problems (it can use COM1-16), and it can be found "out there". We have the 6.12.05 Release Note (11 KB PDF), they skipped 6.12.06 and 6.12.07, we have the 6.12.08 Release Note (100 KB PDF) and the 6.12.09 Release Note (100 KB PDF). The 6.12.09 revision is dated 12/14/2016 and was the last one. All three release notes open in new browser windows. I was told that any version after 6.12.05 locks you to the 12.5 KHz unless you have a "Professional Series" wideband entitlement key – And the keys are different between MotoTurbo (DMR), Professional Series, and Commercial Series (and as of late 2024 none of those keys are available). An email to Repeater-Builder reported that this "feature" bit the sender in the behind when he purchased a radio on eBay that was last programmed with a newer revision. He ended up reselling that radio on eBay and bought another as he needed wideband and couldn't get a key. The replacement CDM was happy with Release 6.12.05. I have been told that the only difference between Release 6.12.05 and the later releases is the forced narrowband, the addition of a few newer model numbers into both the internal programming tables and into the directory that contains the sample codeplug files (and those sample files can be copied from the newer versions into your copy of Release 6.12.05). Unless you really need something in a later release (and you'd better have an entitlement key) there is no need to go anything newer than Release 6.12.05. And always ask the seller what the radio was last programmed with. Motorola's literature says that to program a CDM you need their ribless RKN4081C RJ-45 programming cable. They lie. You don't need to spend $300 with Motorola – your existing RJ-45-style Maxtrac / Radius LRA / GM300 cable (either 9-pin D connector or USB-based) will work just fine for everything but firmware. Motorola's RKN4081C RJ-45 programming cable has a DB25 hood because it's RIBless (there's circuitry inside the DB-25 shell) and a 9-pin hood wasn't big enough. So they ship a 25-pin to 9-pin adapter with it. Photo 1 Photo 2 Photo 3 Here's the PDF that comes with the RKN4081. If you don't already have an RJ-45 cable then get either this 9-pin D connector to RJ-45 cable or this FTDI USB to RJ-45 cable (both links are off-site pointers and open in a new browser tab). If you are going to buy a USB cable then buy an FTDI based cable as they don't need any funny drivers, they work with the stock Windows drivers. I have seen reports on other mailing lists that people have had issues with Prolific-based cables. If you are part of the 1% that will need to update the firmware in a CDM then you will have to build or buy a RLN4853 Adapter Cable (which is easy, it is just two connectors and a few inches of 4-conductor cable). There are details in the CDM Notes article below.
	Recommendation: Save the original codeplug that came with the radio and back up your tuning data (you will need the Tuner program to do that). You never know when you might need them. A firmware upgrade to a Waris radio will not change the tuning information. I repeat: Before you do anything to a new-to-you CDM you need to read and save the original codeplug it came with AND use the Tuner program to read and save the tuning data. Having this data will allow you to fall back to a known starting point if you ever have a problem. It's best to have it and not need it than to need it and can't get it.
	The front panel microphone connector (photo) on a CDM is a 10 pin, not the normal 8 pin (but your 8-pin programming cable will work just fine). The 10 pin connector plug body (photo) is the same size / width as the standard 8 pin and at first glance you won't realize that the CDM has a 10 pin connector. The additional two pins are only used by the CDM-specific DTMF microphone (but it's only a 12 button microphone).
	When programming a CDM mobile or a HT750 / HT1250HT750 / HT1550 (Waris series) handheld do NOT touch anything until you get the second set of beeps after loading a codeplug. The radio will beep when the programming load is complete, then the radio will reset itself and restart. That restart concludes with another beep. WAIT for that post-restart beep! If you start unplugging cables or shut off the power in-between the beeps you stand a good chance of corrupting the radio… This is the voice of experience. Yes, you can recover a corrupted radio, even ones that don't boot, it's almost impossible to completely brick a Waris radio. The Waris pages at the W9CR web site walks you through the recovery process. (off-site pointer, opens in a new browser tab) One caution: Do not let the power fail while programming the radio, ESPECIALLY while flashing / loading firmware. The author programs radios with a laptop that is plugged into an AC outlet and has a good battery. He runs the radio from a common 12 volt 7 amp-hour battery during programming and flashing. Second caution: If you have a remote head or dual head environment Moto recommends that you disconnect any dual head kits or remote kits while programming. They say to use a local head only while programming and ESPECIALLY while loading firmware.
	You can program the CDM through the rear accessory jack if you use a RLN4853 adapter. (link opens in a new browser tab) You can build it yourself from the photo, it's nothing more than a RJ45 female connector, a length of 4-conductor cable, and a 20-pin accessory connector… The schematic is on page 2 of the PDF. The author knows of a group that run a large number of CDMs without any heads – they are used as receivers, exciters, remote bases, full duplex 420-430 MHz links (a pair on each end) and as control receivers. Every single one has been (and is) programmed through the accessory connector.

If you do a lot of radio programming, especially away from the workbench, you might want to consider dedicating a laptop to radio programming. I prefer the Panasonic CF‑30 and CF‑31 series Toughbooks because they are cheap, readily available, Mil-Spec rugged, configurable, repairable and have a 9-pin hardware COM port that always works. I have an article that is linked on the previous page – "Some Thoughts on Radio Programming Computers and Laptops". That article is an opinion piece and my needs are probably different that yours – what works for me may or may not work for you… (but that article may give you some ideas)

Interfacing to External Equipment: (repeater controllers, APRS encoders, etc.)

The CDR500 is the tabletop repeater housing that contains a pair of CDM750s and a RICK module – a very, very basic repeater controller. The CDR700 is the wall mount version. Click here for the CDR500 / 700 brochure.

The rear acccessory connector on a CDM is identified on the schematics as J0501. The interfacing of a CDM is very similar to a GM300 or the previous Maxtrac and Radius LRA radios and you might want to look at those pages at this web site.

One major difference: The GM300 has five channel steering lines allowing selection of 31 channels (plus the one currently selected by (and displayed on) the control head) where the CDM has only four lines (15 channels plus the head). If you need five lines (31 channels + head) then you'll have to skip the CDM and either go back to the GM300 series or use the XPR series radios.

The accessory connector on the rear of the CDM is made by TE-AMP and uses a 20 pin connector body, not 16 like the previous models. The center 16 pins are pretty-much the same, the designer added two pins to the left of the old connector, and two more pins on the right. Your GM300 cable will plug onto the center 16 pins and work just fine – with one exception: pin 15 used to be a speaker connection, it is now an analog output and the pin 15 to pin 16 speaker jumper must be cut. More details below.

Component TE-Amp Digikey Mouser Notes

16 pin Housing 104422-1 104422-1-ND 571-104422-1 Maxtrac, Radius LRA, M10, M120, M130, GM300, R1225

20 pin Housing 104422-2 104422-2-ND 571-104422-2 CDM series

Female Pin 86016-2 A25989-ND 571-860162 (loose pins) or
571-85969-8-CT (a strip of 100 pins) I've provided two part numbers for the Mouser pins as sometimes the loose individual pins are out of stock when the strip of 100 pins is available (100 pins is the smallest bulk amount).

Surprisingly Motorola still recommends the HLN9457 16 pin(!) Hardware Kit for the CDM. It includes sixteen connector pins, five 8-inch-long wires with female pins already attached plus an extra housing.
A wide variety of 16- and 20-pin connector cables and connector / interfacing kits / cable kits can be purchased from ebay seller "mre1032" (Kurt Meltzer, KC4NX / WB9KNX, Meltzer Radio Engineering). (off-site pointer, opens in a new browser tab)

Pin Description Direction Comments Simple Interface

1 Speaker (-) Output Only Not Programmable. DO NOT accidentally ground this pin! Doing so will probably destroy the speaker amplifier (and with the limited CDM parts availability a replacement part will probably not be available). Program the minimum speaker level to zero.

2 External Mic Audio Input Only This pin is high-pass filtered (i.e. the incoming PL tone is stripped) and programmable for pre-emphasis or no pre-emphasis. Input impedance is 560 ohms. Depending on the Tuning settings the deviation on this pin can be limited to a max of about 4 KHz. Transmit audio input. Default is With Emphasis (Not Flat).

3 Digital In #1 Input Only, Active Low Only Fully Programmable, one option is external PTT (EPTT). EPTT (to ground)

4 Digital In #2 Output Only Fully Programmable. Note: this pin is the only one that actively pulls high, and it can handle a small relay coil (don't forget the shunt diode), all the other output pins pull low (to ground).

5 Flat TX Audio Input Input Only This pin is always flat, is not highpass filtered and is appropriate as a external PL or DPL encoder input, digital paging data input, LTR digital data input, etc. Input impedance is 560 ohms.
Note: there is NO deviation limiting on this pin. You must use a service monitor or deviation meter to watch the transmit deviation while setting the input level to this pin. Optional: Connect an external PL encoder (like on a Scom 7330), DPL encoder or paging encoder to this pin.

6 Digital In/Out #3 Input Only Fully Programmable, includes Channel Select

7 Ground Ground

8 Digital In/Out #4 Selectable I/O Fully Programmable, includes Channel Select COS out

9 Analog In #5 Special Input, Tri-state Emergency Switch Programmable, however the only options are Null and External Emergency Switch (Input)
This pin is noted in the Moto documentation as "with Wakeup". See note below.

10 Ignition Sense Special Input Not Programmable, Active High only.
This pin is electrically fragile. If you use this pin you should fuse it with a 1 amp (or smaller) fuse! See the notes further down on this page.

11 Receive Audio Output Output Only Partially Programmable. This pin can be programmed to output either flat or de-emphasized receive audio. Most users will want de-emphasized mode.
Note that like the CDM, like the prior GM300, Radius and Maxtrac series provides squelch-muted, PL-filtered and de-emphasized "handset audio" on one pin of the microphone jack. Receive audio output (de-emphasized).

12 Digital In/Out #7 Selectable I/O Fully Programmable, includes Channel Select

13 Switched Battery +12v out to accessories when the radio is powered on. Not Programmable. This pin can source up to 1 amp (from a dedicated LM2941 regulator inside the radio).
If you use this pin then make sure you fuse it with a 1 amp (or less) fuse!

14 Digital In/Out #8 Selectable I/O Fully Programmable, includes Channel Select Optional: CTCSS decode out.

15 RSSI (Received Signal
Strength Indicator) Analog Voltage Output
zero to 2.4 volts DC Not Programmable
NOTE: On the Maxtrac / Radius LRA / GM300 series this pin was the internal speaker and was normally externally jumpered to the speaker amplifier output on pin 16! If you are going to recycle your old Maxtrac or GM300 cable then you need to cut the pin‑15‑to‑pin‑16 jumper.
This RSSI pin is unprotected and is electrically fragile. It is directly fed from a pin off the SA616 IF integrated circuit. If your controller has an extra analog input connect this DC voltage to it, then program the controller to announce it on command.

16 Speaker (+) Output Only Treat this pin the same as pin 1. DO NOT accidentally ground this pin! Connect an external speaker (floating!) to pin 1 and 16.

17 BUS (+) Bidirectional Not Programmable to other purposes. You can program the radio through this pin.

18 Boot Control Special Input Not Programmable. To enter Boot Mode this line must be grounded when the radio is switched on.

19 Pins 19 and 20 are labeled as NC (No Connection) on some documentation, and "Reserved" on others… But… the Detailed Service Manual shows pin 19 as "UART-RX" and pin 20 as "UART-TX" on the diagram labeled "Controller T2 Schematic Diagram - I/O". These same signals connect to the controller and I/O chips on the diagram labeled "Controller T2 Schematic Diagram - Controller Overall" and to the UART chip on the "Controller T2 Schematic Diagram - Microprocessor" schematic.

20

Accessory Connector Notes:

Like the Maxtrac / Radius LRA / GM300 series an external loudspeaker can be connected to the Accessory connector pins 1 and 16. The CDM control head is designed so that the speaker inside can be disconnected when an external speaker is used (but you have to open up the head to do it).

To have the CDM switch on when DC power is applied just ground pin 9 (i.e. jumper it to pin 7), and program it for Emergency, and "Null". This programming will use the "with Wakeup" feature to force the radio to turn itself on when power is applied. You will want to add a pin-7-to-pin-9 jumper on any remotely located radio (like a link radio or repeater control receiver) so it powers itself up when DC power is applied.

Pin 15 used to be a speaker connection on the GM300 and earlier radios however is now an analog DC voltage output called "RSSI" (Received Signal Strength Indicator) that is unprotected and is directly fed from a pin off the SA616 IF integrated circuit. If you reuse your old GM300 acccessory cable then the pin 15 to pin 16 speaker jumper must be cut. According to the datasheet, it varies from zero to +2.4 volts DC and is calibrated and temperature compensated to within 2 dB over an 80 dB of range. The CDM service manual calls this a linear range from ‑120 to ‑55 dBm of input signal.

Mounting and Brackets:

The mounting bracket bolts onto the CDM with either M5 or 10-32 threads. Moto provided thumb screws with their kits. If you provide your own screws you should trim them to about 1/4 inch length into the radio body – any longer risks damage to the electronics inside the radio.

The GLN7324A is the standard mobile bracket. It will not fits low band CDM as the low-band CDMs are high power only and use a larger body and hence use a larger bracket, the RLN4774A.

The RLN4781A is a bracket that mounts a VHF/UHF CDM into a standard auto radio DIN opening. It's widely used in the UK and Europe for mounting the radio into a taxi or shuttle bus dashboard.

The factory tabletop tray for the CDMs is a GLN7326A. It has a front-facing speaker in the bottom, the GLN7318 is the same plastic tray but without the speaker (but you can add your own).

Novexcomm) (off-site pointer, opens in a new browser tab) makes and sells a dual or single CDM rack mount chassis that is available with or without your choice of a 15 amp 120vAC supply (for low power radios) or a 30 amp 120 / 240v power supply (for high power radios or 240v mains) or no power supply at all (they also do custom work). Look at their eBay store or if you want to save the eBay markup just order direct from their web page. They aren't limited to CDMs, they make their rack mounts with your choice of any brand or model of radio and can customize it.
Disclosure: your page author has known the owner of Novexcomm (WB6SLC) for 40+ years. No, he's not paying for this pointer.

DC Power and Power Supplies:

You don't need a lot of power supply to run a CDM as a control receiver, repeater receiver or link receiver… On receive they draw less than 1/2 amp with the squelch open. Your author knows of a receive-only radio running in the back room at an ambulance company feeding a 24x7 audio logging recorder and running on a 12 volt 3/4 amp wall wart.
The low power (25 watt) VHF and UHF radios draw about 8 amps on transmit, the high power (45 watt) ones pull about 14 amps, the 60 watt low band radios can draw as much as 18 amps.

Motorola offers multiple DC power cords for the CDM:

The HKN4139 (used to be the HKN4137) is the recommended mobile power cable for low power radios. It is 3 meters (about 9.8 feet) long, uses 14 gauge wire and ships with a 15 amp ATO fuse and holder in line.

The HKN4191 is the recommended mobile power cable for high power VHF / UHF radios. It is 3 meters (about 9 1/2 feet) long, uses 12 gauge wire and ships with a 20 amp ATO fuse and holder in line.

The HKN4192 kit is recommended for higher power radios and longer cable runs. It is 6 meters (about 19 1/2 feet) long, uses 10 gauge wire and ships with a 25 amp ATO fuse / holder in line. You will want to use one of these for the low band 60 watt CDMs.

Astron sells the SL-15SCDM 15 amp desktop radio housing / power supply for the low power CDMs.

Samlex offers two different housing / power supply units for the CDM750, CDM1250 and CDM1550 series: the SEC-1212-CDM (12 amp for the low power CDMs) and the SEC-1223-CDM (23 amp for the high power CDMs).

Articles, Modifications and Other Information:

Some CDM notes from Mike WA6ILQ

CDM Product Line Model Number Decoder 473 KB PDF.
This was extracted from the Basic and Detailed service manuals listed below and compiled by Mike WA6ILQ.
If anyone has any of the other region codes he'd appreciate an email.

The CDM-series rear panel Accessory Connector by Robert W. Meister WA1MIK (SK)
Note that the pin numbering is NOT what you would expect… they added 2 pins on each side of the Maxtrac / GM300 16 pin connector…

How to Remove a Motorola UHF CDM 1250/1550 Password By Dennis Rogers N5VRP 107 KB PDF
Dennis's radio group bought a CDM on eBay and found that it had a password… They got around it. While this prodedure was written about his experience with a CDM 1250 or 1550 this process will work on any Waris family radio…

Making the CDM-series Radios Operate Out Of Band by Joel Huntley WA1ZYX (offsite link)
This method requires just some simple hex-editing.

Additional information regarding the above out of band mods 35 kB PDF by James Lawrence NA5RC
Especially important if you are running CPS Revision 6.12.05, which you should be…

Invalid Region Code error? 82 kB PDF by James Lawrence NA5RC
Some CDMs sold on popular auction sites often come from foreign markets and can't be programmed with the standard software distributed in North America. The CPS throws up a big error message. Here's a simple fix using RegEdit (which comes with Windows).

Manuals, Brochures, Guides, and Other Printed Material:

CDM series brochure 1.8 MB PDF
Covers the CDM750, CDM1250, CDM1550, CDM1550LS+ models on low band, VHF, UHF, 200, 700 MHz. 2014 vintage.

Motorola CDM Series Product Overview 3.3 MB PDF
This is a sales document produced to go along with the introduction of the CDM mobiles in 1999.

CDM Series "MotoTurbo" Product Brochure 542KB PDF
This is one of the official "Professional Series" mobiles product brochures. Not shown is the CDR700 update to the dual-GM300-based GR300 tabletop repeater or the dual-CDM CDR500 replacement for the wall-mount GR500. CDR500 External Photo CDR500 Internal Photo CDR700 photo 1 and CDR700 photo 2. Both could be configured as in-band repeat, one-way-crossband-repeat or bidirectional-crossband-repeat. The available acccessory modules that fit into the CDR500 or the top slot of the CDR700 are the same as offered in the GR300.

Standardized Display Nomenclature on the CDM1250 and CDM1550 series radios By Matt Lechliter W6XC 560 KB PDF
The CDM1250 and CDM1550 have a 14 character LCD display. Here's how one system uses it on their repeater and link radios.

CDM and PRO-series Basic Service Manual 3.8 MB PDF
This basic manual covers all CDM and PRO series mobile radios. 6881091C62-E 2012 vintage.

CDM and PRO-series Detailed Service Manual 30.1 MB PDF
This manual covers the Low band, VHF and UHF CDM and PRO series mobile radios. 6881091C63-C 2007 vintage.

CDR500 Wall Mount Repeater & CDR700 Desktop Repeater Service/Programming Manual 1.84 MB PDF 6864110R66-O 2001 vintage.
Motorola used dual CDMs to replace the dual GM300s in the GR500 and renamed the box as the CDR500.
Likewise the tabletop GR300 repeater became the CDR700. This manual was the guide to the field upgrade kits.
NOTE: This manual has almost nothing on the internals of the CDM radios however it does have a lot of info
on the interfacing to the CDMs, plus info on the various add-in controllers: the RICK (HLN3333), ZR310, i20R,
ZR340, HPN9005, HKPN4000, HKPN4001 and the HKN9033.

CDM-series Remote Mount Kit RLN4801 & RLN4802 400 kB PDF 6864110B51-A 2002 vintage.
These kits are the control head extension kits for all CDM-series and some CDM-based GM-series mobile radios.
The RLN4801 is for the CDM750, the RLN4802 is for the CDM1250 and CDM1550 models.
The kits DO NOT include the cable between the head and the radio - that must be ordered separately.
The available cables are 3, 5 and 7 meters long (9.8 feet, 16.4 feet, and 22.9 feet. Page 3 of the PDF has the information.

CDM750 User Guide 1 MB PDF
Not band specific. 6881091C54-A 2003 vintage.

CDM750 Specification Sheet 145 kB PDF
Low Band, VHF and UHF. 2012 vintage.

CDM1250 User Guide 1.3 MB PDF
Not band specific. 6881091C55-B 2003 vintage.

CDM1250 Specification Sheet 60 kB PDF
Low Band, VHF and UHF. 2006 vintage.

CDM1550 Brochure 607 kB PDF
VHF, UHF, 200 and 700 MHz. 2003 vintage.

CDM1550 User Guide 1.3 MB PDF
Not band specific.

CDM Series Control Station Service and Installation Manual 3.99 MB PDF
This manual covers the Control Station (commercial base station) - a CDM in a box with a power supply. Not band specific. 6880309N15-A
This manual has a section on interfacing the CDM to the Control Station Interface Module (CISM) – the CDM version of the R.I.C.K
and that section can be useful in connecting the CDM to an external repeater controller.

Low Band CDM1550 Specification Sheet 90 kB PDF

CDM Basic Service manual 6881091C62-E 3.8 MB PDF

CDM Detailed Service manual 6881091C63-C 30.1 MB PDF

"200" MHz CDM1550LS+ User Manual 6864110R13-O 2.85 MB PDF

CDM1550LS+ 200 and 700 MHz Basic Service Manual (6864110R16 - we don't have a copy yet)
This manual covers both the 200 MHz (model AAM25MHF4DP5AN) and 700 MHz CDM1550 LS+ (model AAM255HF4DP5AN) radios.
The "200" MHz model was the 25 watt 217-222 MHz CDM1550LS+ (model AAM25MHF4DP5AN) radio that was made only in narrowband and 12.5 KHz channel spacing. They didn't even install the wideband receive parts. It CAN be moved to the 219-225 MHz amateur band, but you will need to acquire wideband IF filters and swap them, and then do some software / firmware tweaks to move the band edges and enable 20 KHz spacing. Note that Motorola no longer stocks that exact wideband surface-mount filter (made by Murata) but it can be scavenged from a dead VHF or UHF hulk, or you can use a differently packaged but electrically similar unit.
More info in the "CDM Notes" article above.

CDM1550LS+ 200 & 700 MHz Detailed Service Manual 6864110R14-O 55.8 MB PDF
This manual covers the 200 MHz (model AAM25MHF4DP5AN) and 700 MHz CDM1550 LS+ (model AAM255HF4DP5AN) radios.

CDM Accessories:
This is what the spec sheets recommend:

AARMN4025 Standard Compact Microphone (but your existing Maxtrac / Radius / GM300 microphone will work just fine)

AARMN4026 Enhanced DTMF Keypad Microphone
This 12-button DTMF mic has a 10 pin plug and will not work correctly on anything but a CDM.

AARMN4038 Heavy Duty Microphone

AAREX4617 Telephone Style Handset with Hang-Up Cup
This unit is also compatible with CM200/CM300/PM400 but is not for use with dual control heads.
Includes RLN4756 Handset with Coiled Cord, NTN8378 Hang-up Clip, TRN5502 Mounting Bracket, HLN5549 Mounting Bracket Hardware

HMN3000B Desk Mike for control stations 3 MB PDF
Of course this has been discontinued but was replaced by the RMN5068A.

RSN4001 13 Watt External Loudspeaker

HSN8145 7.5 Watt External Speaker

GLN7324 Standard Low Profile Bracket (VHF/UHF)
This will not work on a low band CDM.

GLN7317 High Profile Mounting Bracket (VHF/UHF)
This will not work on a low band CDM.

RLN4779 Key Lock Mounting Bracket (VHF/UHF)
This will not work on a low band CDM.

CDR500 and CDR700 Accessories 93 kB PDF
The wallmount CDR500 and desktop/tabletop CDR700 prepackaged repeaters were based on dual CDMs. The various items listed in this document are relevant to both the CDM radio and for the CDR500 and the CDR700.

CDM750, CDM1250, CDM1550 Parts Lists and Accessories 381 kB PDF

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Originally this information was on the main Motorola page.
In October of 2016 Mike Morris WA6ILQ created a combined CDM / CM page.
The CM series material was relocated to its own page in October of 2021.

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.

Jump to:	Programming the Waris Radios Interfacing to Other Equipment Articles
	Mounting DC Power Manual PDFs Accessories

	The mounting bracket bolts onto the CDM with either M5 or 10-32 threads. Moto provided thumb screws with their kits. If you provide your own screws you should trim them to about 1/4 inch length into the radio body – any longer risks damage to the electronics inside the radio.
	The GLN7324A is the standard mobile bracket. It will not fits low band CDM as the low-band CDMs are high power only and use a larger body and hence use a larger bracket, the RLN4774A.
	The RLN4781A is a bracket that mounts a VHF/UHF CDM into a standard auto radio DIN opening. It's widely used in the UK and Europe for mounting the radio into a taxi or shuttle bus dashboard.
	The factory tabletop tray for the CDMs is a GLN7326A. It has a front-facing speaker in the bottom, the GLN7318 is the same plastic tray but without the speaker (but you can add your own).
	Novexcomm) (off-site pointer, opens in a new browser tab) makes and sells a dual or single CDM rack mount chassis that is available with or without your choice of a 15 amp 120vAC supply (for low power radios) or a 30 amp 120 / 240v power supply (for high power radios or 240v mains) or no power supply at all (they also do custom work). Look at their eBay store or if you want to save the eBay markup just order direct from their web page. They aren't limited to CDMs, they make their rack mounts with your choice of any brand or model of radio and can customize it. Disclosure: your page author has known the owner of Novexcomm (WB6SLC) for 40+ years. No, he's not paying for this pointer.

	You don't need a lot of power supply to run a CDM as a control receiver, repeater receiver or link receiver… On receive they draw less than 1/2 amp with the squelch open. Your author knows of a receive-only radio running in the back room at an ambulance company feeding a 24x7 audio logging recorder and running on a 12 volt 3/4 amp wall wart. The low power (25 watt) VHF and UHF radios draw about 8 amps on transmit, the high power (45 watt) ones pull about 14 amps, the 60 watt low band radios can draw as much as 18 amps.
	Motorola offers multiple DC power cords for the CDM: The HKN4139 (used to be the HKN4137) is the recommended mobile power cable for low power radios. It is 3 meters (about 9.8 feet) long, uses 14 gauge wire and ships with a 15 amp ATO fuse and holder in line. The HKN4191 is the recommended mobile power cable for high power VHF / UHF radios. It is 3 meters (about 9 1/2 feet) long, uses 12 gauge wire and ships with a 20 amp ATO fuse and holder in line. The HKN4192 kit is recommended for higher power radios and longer cable runs. It is 6 meters (about 19 1/2 feet) long, uses 10 gauge wire and ships with a 25 amp ATO fuse / holder in line. You will want to use one of these for the low band 60 watt CDMs.
	Astron sells the SL-15SCDM 15 amp desktop radio housing / power supply for the low power CDMs.
	Samlex offers two different housing / power supply units for the CDM750, CDM1250 and CDM1550 series: the SEC-1212-CDM (12 amp for the low power CDMs) and the SEC-1223-CDM (23 amp for the high power CDMs).

	Some CDM notes from Mike WA6ILQ
	CDM Product Line Model Number Decoder 473 KB PDF. This was extracted from the Basic and Detailed service manuals listed below and compiled by Mike WA6ILQ. If anyone has any of the other region codes he'd appreciate an email.
	The CDM-series rear panel Accessory Connector by Robert W. Meister WA1MIK (SK) Note that the pin numbering is NOT what you would expect… they added 2 pins on each side of the Maxtrac / GM300 16 pin connector…
	How to Remove a Motorola UHF CDM 1250/1550 Password By Dennis Rogers N5VRP 107 KB PDF Dennis's radio group bought a CDM on eBay and found that it had a password… They got around it. While this prodedure was written about his experience with a CDM 1250 or 1550 this process will work on any Waris family radio…
	Making the CDM-series Radios Operate Out Of Band by Joel Huntley WA1ZYX (offsite link) This method requires just some simple hex-editing.
	Additional information regarding the above out of band mods 35 kB PDF by James Lawrence NA5RC Especially important if you are running CPS Revision 6.12.05, which you should be…
	Invalid Region Code error? 82 kB PDF by James Lawrence NA5RC Some CDMs sold on popular auction sites often come from foreign markets and can't be programmed with the standard software distributed in North America. The CPS throws up a big error message. Here's a simple fix using RegEdit (which comes with Windows).

	CDM series brochure 1.8 MB PDF Covers the CDM750, CDM1250, CDM1550, CDM1550LS+ models on low band, VHF, UHF, 200, 700 MHz. 2014 vintage.
	Motorola CDM Series Product Overview 3.3 MB PDF This is a sales document produced to go along with the introduction of the CDM mobiles in 1999.
	CDM Series "MotoTurbo" Product Brochure 542KB PDF This is one of the official "Professional Series" mobiles product brochures. Not shown is the CDR700 update to the dual-GM300-based GR300 tabletop repeater or the dual-CDM CDR500 replacement for the wall-mount GR500. CDR500 External Photo CDR500 Internal Photo CDR700 photo 1 and CDR700 photo 2. Both could be configured as in-band repeat, one-way-crossband-repeat or bidirectional-crossband-repeat. The available acccessory modules that fit into the CDR500 or the top slot of the CDR700 are the same as offered in the GR300.
	Standardized Display Nomenclature on the CDM1250 and CDM1550 series radios By Matt Lechliter W6XC 560 KB PDF The CDM1250 and CDM1550 have a 14 character LCD display. Here's how one system uses it on their repeater and link radios.
	CDM and PRO-series Basic Service Manual 3.8 MB PDF This basic manual covers all CDM and PRO series mobile radios. 6881091C62-E 2012 vintage.
	CDM and PRO-series Detailed Service Manual 30.1 MB PDF This manual covers the Low band, VHF and UHF CDM and PRO series mobile radios. 6881091C63-C 2007 vintage.
	CDR500 Wall Mount Repeater & CDR700 Desktop Repeater Service/Programming Manual 1.84 MB PDF 6864110R66-O 2001 vintage. Motorola used dual CDMs to replace the dual GM300s in the GR500 and renamed the box as the CDR500. Likewise the tabletop GR300 repeater became the CDR700. This manual was the guide to the field upgrade kits. NOTE: This manual has almost nothing on the internals of the CDM radios however it does have a lot of info on the interfacing to the CDMs, plus info on the various add-in controllers: the RICK (HLN3333), ZR310, i20R, ZR340, HPN9005, HKPN4000, HKPN4001 and the HKN9033.
	CDM-series Remote Mount Kit RLN4801 & RLN4802 400 kB PDF 6864110B51-A 2002 vintage. These kits are the control head extension kits for all CDM-series and some CDM-based GM-series mobile radios. The RLN4801 is for the CDM750, the RLN4802 is for the CDM1250 and CDM1550 models. The kits DO NOT include the cable between the head and the radio - that must be ordered separately. The available cables are 3, 5 and 7 meters long (9.8 feet, 16.4 feet, and 22.9 feet. Page 3 of the PDF has the information.
	CDM750 User Guide 1 MB PDF Not band specific. 6881091C54-A 2003 vintage.
	CDM750 Specification Sheet 145 kB PDF Low Band, VHF and UHF. 2012 vintage.
	CDM1250 User Guide 1.3 MB PDF Not band specific. 6881091C55-B 2003 vintage.
	CDM1250 Specification Sheet 60 kB PDF Low Band, VHF and UHF. 2006 vintage.
	CDM1550 Brochure 607 kB PDF VHF, UHF, 200 and 700 MHz. 2003 vintage.
	CDM1550 User Guide 1.3 MB PDF Not band specific.
	CDM Series Control Station Service and Installation Manual 3.99 MB PDF This manual covers the Control Station (commercial base station) - a CDM in a box with a power supply. Not band specific. 6880309N15-A This manual has a section on interfacing the CDM to the Control Station Interface Module (CISM) – the CDM version of the R.I.C.K and that section can be useful in connecting the CDM to an external repeater controller.
	Low Band CDM1550 Specification Sheet 90 kB PDF
	CDM Basic Service manual 6881091C62-E 3.8 MB PDF
	CDM Detailed Service manual 6881091C63-C 30.1 MB PDF
	"200" MHz CDM1550LS+ User Manual 6864110R13-O 2.85 MB PDF
	CDM1550LS+ 200 and 700 MHz Basic Service Manual (6864110R16 - we don't have a copy yet) This manual covers both the 200 MHz (model AAM25MHF4DP5AN) and 700 MHz CDM1550 LS+ (model AAM255HF4DP5AN) radios. The "200" MHz model was the 25 watt 217-222 MHz CDM1550LS+ (model AAM25MHF4DP5AN) radio that was made only in narrowband and 12.5 KHz channel spacing. They didn't even install the wideband receive parts. It CAN be moved to the 219-225 MHz amateur band, but you will need to acquire wideband IF filters and swap them, and then do some software / firmware tweaks to move the band edges and enable 20 KHz spacing. Note that Motorola no longer stocks that exact wideband surface-mount filter (made by Murata) but it can be scavenged from a dead VHF or UHF hulk, or you can use a differently packaged but electrically similar unit. More info in the "CDM Notes" article above.
	CDM1550LS+ 200 & 700 MHz Detailed Service Manual 6864110R14-O 55.8 MB PDF This manual covers the 200 MHz (model AAM25MHF4DP5AN) and 700 MHz CDM1550 LS+ (model AAM255HF4DP5AN) radios.

	AARMN4025 Standard Compact Microphone (but your existing Maxtrac / Radius / GM300 microphone will work just fine)
	AARMN4026 Enhanced DTMF Keypad Microphone This 12-button DTMF mic has a 10 pin plug and will not work correctly on anything but a CDM.
	AARMN4038 Heavy Duty Microphone
	AAREX4617 Telephone Style Handset with Hang-Up Cup This unit is also compatible with CM200/CM300/PM400 but is not for use with dual control heads. Includes RLN4756 Handset with Coiled Cord, NTN8378 Hang-up Clip, TRN5502 Mounting Bracket, HLN5549 Mounting Bracket Hardware
	HMN3000B Desk Mike for control stations 3 MB PDF Of course this has been discontinued but was replaced by the RMN5068A.
	RSN4001 13 Watt External Loudspeaker
	HSN8145 7.5 Watt External Speaker
	GLN7324 Standard Low Profile Bracket (VHF/UHF) This will not work on a low band CDM.
	GLN7317 High Profile Mounting Bracket (VHF/UHF) This will not work on a low band CDM.
	RLN4779 Key Lock Mounting Bracket (VHF/UHF) This will not work on a low band CDM.
	CDR500 and CDR700 Accessories 93 kB PDF The wallmount CDR500 and desktop/tabletop CDR700 prepackaged repeaters were based on dual CDMs. The various items listed in this document are relevant to both the CDM radio and for the CDR500 and the CDR700.
	CDM750, CDM1250, CDM1550 Parts Lists and Accessories 381 kB PDF