cdm 1250 repeater question

[moustache]

Hello, I have a cdm 1250 in my work truck and have a second unit that I just purchased.
I would like to hook them up as a repeater so that I can use them with my portable radio a (ht1250)
I am not a radio tech but have a basic understanding of how other repeaters work. I was hoping someone could tell me specifically what I would have to do for the cdm to get them to work. Also any special programming I would have to do to each radio. Any information would be greatly appreciated. Thank you in advance for your time in reading this post..

[arnu]

It's not a problem to hook two CDM1250 together as repeater but ...

Several issues you need to consider:
- You will need a (duplex) frequency pair or 2 (simplex) frequencies to run them as repeater - does your license provide that ?
- You will need a duplexer though - to separate the transmitter from the receiver.
The duplexer must be professionally tuned to your frequencies.
Both radios will use the same antenna. (No you can't use 2 antennas - at least not with less then 30 ft between them)
- One radio will be used for receive - one for transmit (Duplex frequency pair) or
one for Mobile-Base and the other for Mobile-Portable (two simplex frequencies)
- Your portable and mobiles need to be programmed to use the repeater frequencies, CTCSS, etc ...

So there are quite a few things to keep in mind to make a mobile repeater work successfully.

Alfred.

[Jim202]

Hello, I have a cdm 1250 in my work truck and have a second unit that I just purchased.
I would like to hook them up as a repeater so that I can use them with my portable radio a (ht1250)
I am not a radio tech but have a basic understanding of how other repeaters work. I was hoping someone could tell me specifically what I would have to do for the cdm to get them to work. Also any special programming I would have to do to each radio. Any information would be greatly appreciated. Thank you in advance for your time in reading this post..

With the other comments about the issues of using the two radios, nothing was mentioned about on what frequencies you plan to use this configuration on. If it is for the ham bands, then your pretty much can do what you please. If this is for a business frequency or a public safety frequency set, then you will need to follow the FCC guide lines about license considerations for this type of operation.

Jim

[Will]

I think the OP meant some sort of vehicle cross band repeater to extend his handheld radio away from the car. That used to be called an "Extender", CHP still uses them.

IF so, you need a second radio, low power is good for this application. An interface similar to the bidirectional 'repeater' cables offered on the EBay. And of course a second antenna on the vehicle.

We used to build the Extender Module that was plug and play for the CDM mobile radios.

Forum: General Motorola Radio Discussion
Topic: USING A R.I.C.K. WITH CDM1250 RADIOS

[moustache]

Thanks to everyone for your help and input.

An extender application is what I am trying for...