Talkback quit working

[iceman78]

i put talkabck in my project radio (cobra 19+). it worked for a littlew while then quit working all together. was wondering if anyone has a little pearl of wisdom on how to rectify this. i tried out a new resister and that didnt help. am using the recommended resistor according to cbradiomag.com (100 ohm, 1W). did this in my 148 without incident. thanks for your help

 

[Cityboy]

Where did you install the resistor? Was it across the PA and EXT speaker ground pads, or did you install across the internal speaker. The 100ohm is ok but the 1W resistor is a little too much. I would use 2 100ohm resistors twisted together(50ohms total) at a 1/4 watt rating. You could go up to a 1/2watt each to give you the same power disapation as your original set-up. The 50 ohms should give you pretty loud talkback. Let me know how it turned out.

 

[iceman78]

the resistor is across pa & ext sprk pads...same as i did in my 148 without incident. pa, internal sprk, ext. spkr, and mic work fine. also tried a brand new resistor too. funny thing is that the talkback worked just fine then quit working. curious

 

[Cityboy]

Just wondering what kind of mic you are using; sometimes the impedence of the mic may have done something to the radio. Is the mic a small and very thin and may say electret microphone or high impedence. Just wondered.