CDM Remote Mic & Speaker

[Travelin Man]

Hey friends, got a quick question for you all.

I'm spec writer for fire apparatus, and one of my customers uses CDM1250's (VHF) for their operations. They want to mimic what they have on the fire engine they're replacing, which is a mic and remote speaker on the pump panel. However, today I got the following message from one of the fire engine manufacturers who's bidding on the vehicle:

"...The specs are calling for a pump panel microphone and speaker to be used in conjunction with the radio (Motorola CDM 1250). I have been informed via our Motorola Vendor that you would need a dual control head to achieve this and the CDM series is only a single control head. Also the CDM series is being phased out by Motorola. The information I have been given is that option is not available..."

Does this sound accurate? They've got two other vehicles with this setup (one done by a Motorola dealer, the other was done by the FD in-house using leftover radio parts they had), so it honestly can't be that hard. Hell, I found a 3rd party harness on eBay that would accomplish exactly what we're looking for for about $30.

Also, what's replacing the CDM series?

Thanks guys!

[jackhackett]

You can do remote mic and speaker on a CDM. The connections you need are all on the accessory connector.
This will allow you to transmit and receive from the pump panel, but it won't let you see what channel you're on or change channels, for that you would need either a dual head radio or two separate radios.
If the customer just wants to be able to talk from the pump panel and doesn't need to control the radio from there, remote mic/speaker is fine.

They've been saying they're discontinuing CDMs for a while now, some models are already gone. I'm not sure what their plans are for the remaining ones.
As far as I know, the replacement for them is the MotoTRBO series. Keep in mind that CDMs were never meant to be public safety radios, they just ended up being used for that because of price. For public safety Moto is currently pushing the APX radios.

[SteveC0625]

Hey friends, got a quick question for you all.

I'm spec writer for fire apparatus, and one of my customers uses CDM1250's (VHF) for their operations. They want to mimic what they have on the fire engine they're replacing, which is a mic and remote speaker on the pump panel. However, today I got the following message from one of the fire engine manufacturers who's bidding on the vehicle:

"...The specs are calling for a pump panel microphone and speaker to be used in conjunction with the radio (Motorola CDM 1250). I have been informed via our Motorola Vendor that you would need a dual control head to achieve this and the CDM series is only a single control head. Also the CDM series is being phased out by Motorola. The information I have been given is that option is not available..."

Does this sound accurate? They've got two other vehicles with this setup (one done by a Motorola dealer, the other was done by the FD in-house using leftover radio parts they had), so it honestly can't be that hard. Hell, I found a 3rd party harness on eBay that would accomplish exactly what we're looking for for about $30.

Also, what's replacing the CDM series?

Thanks guys!

Jack's 100% correct on this.

If you are looking at mre1032's Cable#97, that's exactly what would be needed to accomplish remote mic and speaker without remote channel change or volume control. The speaker wires would have to be extended, of course. (Word of caution, those speaker wires must be isolated. If they are grounded to the truck chassis, it will blow the audio circuit in the radio.)

If you wanted to step up a bit and give volume control at the pump panel, one of Motorola's amplified speakers would do the trick. There is already optional low level Rx audio available in this cable. He also offers an add-on kit for amplified remote Rx audio.

BTW, if you search here on the batboard, you will find a number of great recommendations for mre1032. He's good people.

[nukedude]

+1 for mre1032's items. I have used his cables and cross band repeater interface units for Motorola radios many times over the years. Prices are very economical and it has allowed my work to use CDM1250's for many things we never would have even though of.

We have also extended our CDM1250's for use on ships as described above. These are for vessels with remote pilot stations on the bow, so you can "drive" over an oil slick for recovery operations. We just extend the speaker and mic to this location, keeps the transmitter on the bridge.

[Will]

A Power Voice amplified speaker at the pump panel with a volume control. The filtered audio out of the CDM would be used to feed the power voice amplified speaker via a shielded line.
The mic lime needs to be shielded and isolated also. Add a LED TX indicator at the panel too.