clegg fm - 28 tone board

[agillot]

won a clegg fm 28 at the last club meeting [ raffle ] , no body wanted it , it is in perfect condition , did install a ss32 tone board , now , repeaters come on , but i get a load hum with mic key depressed , voice become not readable .at the rear of radio , there is a 7 pin socket , pin 1 is for tone , and 7 ground .i tried to turn down the adjustable output of board , but the hum does not change .the manufacturer of board is not familiar with this radio .this board work fine on a old kenwood tr 7400 a .any idea . thanks alain , kd6sbn

[k9yli]

I had a similar problem on an old kenwood. it was caused by the power lead i put in for the tone board.
use rg174 for power and signal. ground the shield on only one end .. unless both ends help..
It could be caused by where your wires run past other audio componenets on the boards.
try moving the tone board around as a test function. You may need some shield between it and other components. ..