Non techs, stay out of these exports....

[brandon7861]

Yes, he tested his jumpers and they were fine, he used new ones anyway, same result.

C199 maybe?
I think there is mention of the galaxy 44v aquirring an oscillation on transmit audio which turns out to be C199.

It's on the archived version of cbtricks under galaxy symptoms and cures.

Not really a hum. Almost a 1khz constant tone but lower in frequency tone, like say 600hz to 800hz.

SWR between radio and the amp is 1.3, SWR from antenna is 1.3.

This issue may be the reason someone recapped it and tried to align it (which screwed up the alignment) and then sold it.

I found this:


and although I don't have a saturn schematic on hand that is clear enough to read, the DX45 schematic shows where this cap is. Looks like the mod simply replaces the jumper with a ceramic cap (in this radio, C193) that bridges the chassis to circuit ground

 

[brandon7861]

Is it possible that the saturn had a jumper instead of cap there too?

 

[Hawkeye351]

Not sure, but I will check. Picking it back up this weekend to go over it to find the issue.

 

[loosecannon]

You might need him to bring the radio and the mic he uses, and at least one of his amps so you can try to reproduce the problem on your bench.

he might have some sort of ground loop issue.

if that RCI base has its main PC board DC ground isolated from the chassis, he might be connecting the two unintentionally with some other piece of equipment.

for example, if the shield wire of his D104 is connected to the shell of the mic plug then he's connecting the PC board ground to the chassis ground with that mic shield wire.

sorry it's late here, maybe im not explaining myself very well lol.
LC

 

[Hawkeye351]

Finally got around to throwing this one back in the desk to figure out that 1k constant tone on transmit (carrier) issue.

Someone had bridged the collector of the AMC limiter (TR32) to another circuit which went straight to pin 7 of the mic amp (4558), I fixed that mess. This in turn connected pin 3 and pin 7 of the mic amp together. This also in turn shorted out the mic amp, c128 (1uf 50v tantalum) and an electrolytic right next to c128 thats also marked as 1uf 50v.

After replacing those, the audio sounded so much better, but that tone was still present.

Turned echo on and it roared. Figured it could be the echo board so I completely removed it and connected all the needed wires together to complete the circuit without the echo board.

BAM!!!!!!

Echo board was bad too.

Radio is excellent now, minus echo.

Those old galaxy Saturn echo boards cause more problems than they're worth.