i just purchased a astatic eb1 echo board and i have a cobra 29 LTD Classic with an inline roger beep and donkey fart when i hook it up like the instructions say it makes a loud distoreded squealing noise. the only thing different from the instructions i am doing is hooking the audio wire from beep and fart to the audio mic pin.But when i hook it to my cobra 25LTD with double roger beep it works fine any sugestions.
Where are you grounding the echo board? If you are grounding to a can, I have found it's not a good enough ground. Ground to the mic jack.
Also, do you like this echo board? I have never liked the sound quality of this board...prefer the LT-2. I guess for $7.99 usd I shouldn't expect much.