pro 651 low audio to feed

[dmoore12345]

I got a pro 651 today and hoped to use it as a new radio for an existing feed. I plugged the existing feeds audio cable into the headphone jack of the pro651 and the audio is very very low @ any volume setting. I tried a pair of earphones on the 651 and the audio was fine. Does the pro651 have a dropping resistor? Thx in advance..

 

[jim202]

I got a pro 651 today and hoped to use it as a new radio for an existing feed. I plugged the existing feeds audio cable into the headphone jack of the pro651 and the audio is very very low @ any volume setting. I tried a pair of earphones on the 651 and the audio was fine. Does the pro651 have a dropping resistor? Thx in advance..

Not saying this is the problem, but check and see if there is a DC bias voltage on the audio connection from the source radio. If so, you may be loading down the line and need to add a dc coupling capacitor to correct the problem. Adding a 1.0 uf capacitor in series with the audio line should correct the problem.

If yo don't have any DC voltage on the line then ?you may have a serious miss match in the audio impedance. It might take putting in a matching transformer to correct it.

 

[dmoore12345]

thx for the response...I fixed it but not 100% how... I added a PAC SNI-1/3.5 3.5-mm Ground Loop Noise Isolator and it seemed to fix the issue, not sure if that makes any sense? rebooted the computer and jacked around with a few other things but not sure which fixed it...