The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

hello all..i have a connex 3300 with the ept-360014b pc board.this is older unit with only single final output. the unit output power is good..dead keys about 2 watt and swing 20..but on rx and tx audio,i get a solid buzzin or hummin sound that overtakes the incoming rx audio..and on tx is the same.i set a handheld test radio up beside..and it has a solid hummin or buzzin sound that in the audio..i read a thread someplace where it could be c-128 o/s causing dc ripple to get in audio.but the strange thing is that this only happens in d-band regular cb frequencies..in all other bands and even fm mode it is o.k.nice quite audio,no buzzing/humming..any ideas would be appreciated..thanks in advance...............ramblingman

Do you have audio hum on the top channels of band C (37.38.39 and 40)and bottom for E1,2,3and 4)?

Have you try adjusting the VCO? Have you tried scoping the output of the VCO?

Have you tried checking main voltage reg with a scope?

You should be able to find the hum quickly with a scope.

thought id leave a update on this radio..found the problem.bad solder connection in the vco area.....thanks for the help rick......ramblingman