CB Over Amplified PA

[Wheelerdude]

I installed an amp for my PA. After installing the amp I hear the radio over the CB's speaker as usual, but it also broadcasts over the PA speaker (amp turned on) with the CB in "CB" mode. Turn off the amp and I only get CB sound over the CB's speaker. And yes, I triple-dog checked that I'm on the PA jack! What's going on? In PA mode it works as advertised.

Both the radio and amp are wired (individually) directly to the battery. It's a 2-channel, 80W amp and a 979 radio. Is the amp sucking the sound out of the radio, or are there RFI issues?

[Z-MAN]

Im confused, you installed an Amp for your PA? Turn off the talkback?

[Slyguy]

I would figure out a way to power down the amp unless you key the mic in PA mode using the remote line on the amp. When the amp is powered up, its looking for something to amplify. Just a thought.

[Wheelerdude]

Good thought. Didn't think I'd run into this "challenge". Starting to wonder if there is such a thing as a quick and easy project! :0)

[Deleted User 14541]

You could build an RF triggered circuit (like a keying circuit in an amp) that would disable the pa amp. There may also be a way to wire the amp through the pa switch on the radio so that its disabled when the switch is set to CB.

[MDYoungblood]

You must have one heck of a PA speaker to need an 80 watt amp to run it. Okay with that said I hope you are using a mono plug on the back of the radio for the PA jack. How do you have a 2 channel amp hooked into a single channel PA system? Talk back is not the issue if you are hearing the receiving signal not you transmitting. To me you need to look at your setup again and figure out where you have the wires crossed. Next check inside the radio and make sure no one has tried to do a talkback mod by jumping a resistor across the EXT SP/ PA jacks.

3's

Greg

[dirtyjob]

why do you need to amplify your pa?

[Wheelerdude]

The amp was only $10. Besides, I leave for work at 0430...just kidding! Again, for $10, why not?? :0)