One Mic with Multiple CDMs Mobile Install

[W1HVN]

Installing 3 CDMs and one Radius/Maxtrac in mobile install. Would like to use 1 mic for all 4 radios. Suggestions for switching?

[akardam]

(Number of pins in mic)P(Number of radios)T

Problem solved.

[W1HVN]

Anybody know of anything sold commercially without building one? I believe there is a multi-radio control panel available for mobile use which also acts to link the radios via the accy ports?

Would a Multi-port RJ45 CAT 5 4 option switch work, mount behind a blank console panel and expose only the switch knob and add labels to panel?

Thanks much.

Trying to stay away from making one. If need be I'll "P-T" it, just looking for a less time consuming answer for now.

[wavetar]

4-to-1 RJ11 switch boxes do exist...here's a link as an example:

http://www.bgstores.co.uk/electronic-36 ... -1259.html

Your local electronics store should be able to order one in for you. HOWEVER, each radio will be sending approx 8.75 Vdc on the tx audio line in order to bias the mic element, which will lead to all sorts of trouble. You need to have one of the radios sending this voltage, and the other three need to have a capacitor placed in line to block the DC while allowing audio to go through. I don't know if this can be easily done inside the switch box or not.

[jackhackett]

If the switchbox switches all of the pins you wouldn't need (and wouldn't want) to DC block the mic hi leads.

Edit: One thing to keep in mind in that case... mic hang up is going to get disconnected on all of the radios not switched to the mic.

In radio, nothing's easy.

[wavetar]

You are correct, I was for some reason thinking all radios being connected at once, as I had to do that for a dispatch application at one point. The switch box should be all you need, disregard what I said earlier.

[motorola_otaku]

Anybody know of anything sold commercially without building one? I believe there is a multi-radio control panel available for mobile use which also acts to link the radios via the accy ports?

I think this is what you're looking for: http://ncsradio.com/commercial/C250.shtml

[wavetar]

Anybody know of anything sold commercially without building one? I believe there is a multi-radio control panel available for mobile use which also acts to link the radios via the accy ports?

I think this is what you're looking for: http://ncsradio.com/commercial/C250.shtml

That is a neat little box.

[wavetar]

Edit: One thing to keep in mind in that case... mic hang up is going to get disconnected on all of the radios not switched to the mic.

In radio, nothing's easy.

You can always program the CDM radios to remain 'on hook' at all times, ignoring the mic state. If it's a GM300 being installed, it can also be programmed that way, if memory serves. Otherwise the hook line can be grounded within the radius/maxtrac control head.

[W1HVN]

That's the one...

Really great device.

Retail is about $2k with the COR lines

Anybody know of any dealers who can shave a good amount fromt he MSRP?

Thanks for the help