Batboard

I have a CDM 750 VHF radio about 9 months old. It is connected to a CPI MR200N tone remote. Twice in the last 3 months the radio will emit on the tone system, receive only , the low pitched warning tone, like the alert on TOT . I remove the DC power , turn it back on , and it works fine.

Anyone else had this problem?

Think we need some more details here on the issue. A little bit of help might just get you a little bit of an answer.

Do you listen to the radio transmitter at issue to hear if it is hung in transmit?

Have you checked the radio programming to see if the TOT is set and functional?

Where are you picking off the power to run the CPI termination panel?

Have you monitored the remote control line to hear if there is any cross talk on it?

Have you put a volt meter on the PTT line to see what the voltage is when this problem occurs?

What is the environment where this radio is? Are there any TV transmitters of FM stations on the same tower or real close?

Jim

JD wrote:I have a CDM 750 VHF radio about 9 months old. It is connected to a CPI MR200N tone remote. Twice in the last 3 months the radio will emit on the tone system, receive only , the low pitched warning tone, like the alert on TOT . I remove the DC power , turn it back on , and it works fine.

Anyone else had this problem?

Additional information:

1.) Radio does not transmit when this tone is present, radio is locked in receive mode.
2.) TOT does work, I thought maybe this was the problem but not the case.
3.) CPI tone panel powered off of same power supply as radio, Duracomm switching unit , 22 amp cont.
4.) I can not do much testing of the lines due to the fact that the 2 times this problem has occured, thhe buses are out and the custimer has to have communications as soon as possible.
5.) No other transmitters within a few hundred yards.

Thanks

Sounds like the CPI tone panel gets stuck in xmit, or at least is holding the radio PTT line low. The next time it happens, pull the accy plug to the radio to see if it stops making the tone. If it does, then the CPI is holding PTT down, and you either troubleshoot it, or replace it.