Cobra 29 LX Talk Back Issue

[ZigZag747]

I just purchased the radio and installed it in replace of my Cobra 18WXSTII...Really like the radio and everything is working well just not sure about the low talk back volume. I noticed the issue when I first began going through all the functions of the radio, I turned the Var Knob for T Back on and could barely hear as I spoke into the mic...With the knob turn "full-on", I still could barely hear the talk back...I've only been able to find a few ref concerning this issue, one referred to a 1 cent resister placed in a certain location...Is this normal for the T Back to be so low or is my radio needing an adjustment? And if so what adjustment should I do...Any help would be greatly appreciated...Thanks.

r/
Moonchild

 

[gewecke]

Just use the radio without the talk back.
You know what you sound like right?


73,
n9zas

 

[XTS3000]

Talkback can be louder by adding a 1/2 watt 33-75ohm resistor in a certain spot. If you can take a photo of the solder side of the board, I can tell you where to put the resistor.

I agree the talkback is WAY to quiet.

Talkback can be handy to let you know if your mic audio is breaking up due to a back mic cord.

 

[ZigZag747]

rgr I'll have to take the radio out of the truck tonight, appreciate the assistance. Another feature I have found not much use for is the Delta Tune...I understand it's purpose but don't think there is much drift on the bands to need it...Was thinking about getting an echo board and control it from there.

 

[ZigZag747]

Sorry, quickest way for me to do this was grab the schematic, hope you can show me the location based off this JPG...Thanks again.

 

[kb2vxa]

That's not the schematic, nor is it the underside of the board, it's the parts location diagram viewed from the top.

Volume is set low to avoid feedback. CBs have enough echo boxes, pings, beeps and noisemakers already without adding screeching and squealing to the mix. IMO the only thing talk back is good for is when there's nobody else to talk to so you don't get bored.

 

[ZigZag747]

Below is a photo of the board, solder side up...Alos just discovered that when I turn my talk back off my audio for the CB turns off also...so I decided to easter egg and plugged in an external speaker and was able to get audio which turned off when the Talk back was turned off also...So I decided for some reason to plug in to the PA and was astonished to hear truckers on the PA speaker even when I was in PA mode...Something tells me that I have a possible messy solder job that bleed over to another connector on the audio side (Thinking somewhere close to the PA and Ext Speaker connectors)...If anyone could ponder that for a min and shoot me some advice I'd be glad to T/S in that direction. Right now I need to get in to the Schematic's and make some calls to Cobra...

 

[ZigZag747]

BTW this was purchased from a Pilot Truck stop in SC and was not modified nor was it purchased used...

 

[ZigZag747]

Found the issue

Ok...Cobra 29 LX is fine, issue was my old Cobra Power mic there was a ground in the mic between pin 1 and 4...I put the original mic back on and found everything worked as normal...Talk Back was restored speaker was louder now, no cross over on the PA...Did notice a hazy film on the back side of the circuit board which was whitish in color...I took some Isopropyl alcohol and an acid brush and cleaned up the back just to be sure. Did notice a few bad solder points also which I fixed up. Radio is working great now...Happy Days.