CDM Repeater c/w CS-800

[johnny1225]

I have a CDM Repeater with (2) CDM1250 mobiles rx 408.8375 and tx 406.5375 TPL 156.7. It is hooked up to a CS800 and is hooked into a basic Rick Controller. There is alot of static when receiving and transmitting phone calls. The two way radio system is working great. We have switched repeater with a brand new one, switched the CS800 with a brand new one and still have the noise on the line when using the phone part of the system. We have had the phone lines tested twice and they are in good working order. I was wondering what should i check, is the CS800 need adjustment of some type, what may be producing this loud hum on the phone line?

Thank you in advance for your responds

John

[HLA]

can you describe the noise more? is it like a 60hz hum or like white noise or pink noise or distorted like it's overdriven or a screeching sound like feedback?

[johnny1225]

it is like a white noise in the background and then once an awhile there is like a short scretch, almost like interferance but we checked to make sure the repeater TPL code was working.

John

[Jim202]

The little info that you have provided might lead me to think about the audio level settings. One of the
first questions to be asked is how heavy is the telephone audio on the radio? If it is loud or over powering
I would go for adjusting down the audio gain from the phone line. If you have too much gain, it will bring
up any and all background noise and put this over the radio.

To prove the gain issue, how far from the telephone can you have someone talking and still hear them?
It sounds like your driving the radios way into compression from the telephone side of the audio input.
If your able to pull the telephone more than a few inches away from the speaking persons mouth and
still hearing them fine, then this proves you have way too much gain on the telephone input.

You might also have the repeater audio throughput set wrong. The repeater should be set up audio gain
wise so that if you put a 3 KHz deviated audio level into it, you get 3 to 3.25 KHz deviation out of the
repeater. This assures that your repeater is not compressing the audio passing through it. One test
for this is to not speak into the mic on the user radio keying the repeater. Have someone talk a couple of
feet from the mic. You should not normally hear it. Or have a vehicle engine running in the background.
You should not hear the engine. If you do, I would look at the mic gain on the user radio and question
the audio gain passing through the repeater.

After you make a few tests on your stystem, come back with the results and someone can probably
guide you in solving the problem.

Jim