galaxy 44 with rfx 75 squels when covers are on

[johnecashflo]

i recently installed a rfx 75 on an older single final galaxy 44.. it works fine when the covers are off the radio...the problem is when you put the solder side cover on the radio it goes in to lock down mode(full power with a squel) as soon as you key the mic. with the talkback on or off .. has anyone installed one of these on a 3600 chassis? and if so did they have any similar problems..thanks for any help or suggestions on what to do to remedy the problem........

 

[ouxly40]

Feedback

There are a lot of radios that will feedback when the rfx is installed. Usually, I do several things and it stops somewhere along the way. Hopefully, you have cut all the internal coaxes and wires as short as possible!!!
1. Pay attention to input coax and output coax. They should not run alongside one another.
2. Put ferrite beads on wires - especially ground, bias and Vcc. Ferrites on the coaxes are a trial and error procedure. Do them one at a time and note any changes.
3. This one usually does the trick but requires some patience. Take a double clad circuit board and solder it to the top of a few of the IF/RF cans. You will have to try a few locations but usually you are dealing with high level modulated RF getting back into IF or especially audio circuits.
During installtion I always cut all wires as short as possible and install ferrites on grounds, dc and bias wires. Most radios do fine. You may also have to put the modulation limiter back into play...

 

[ouxly40]

Squeals...

Or,,, you could leave the cover off???