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Robyn GT7 C low modulation.


Pretty sure it's every bit of 45 years old. Fair chance that age is the cause of the trouble, and not some adjustment that's turned down too low.

You'll hear advice to "re-cap" a radio this old. The aluminum electrolytic capacitors just don't hold up that long. Don't know how many of those are in this model, but I'm pretty sure a handful of them are in the mike audio circuits.

Just one problem. You won't find out if that's gonna fix it until you have changed all two or three dozen of those parts.

An experienced pro could zero in on the cap that's causing a particular fault. And changing just "the one" cap that causes today's symptom leaves the rest of them to come up later on. We call that "electronic whack-a-mole".

Do you have a way to check the mike on another radio?

Or another mike on this radio?

73
 
Pretty sure it's every bit of 45 years old. Fair chance that age is the cause of the trouble, and not some adjustment that's turned down too low.

You'll hear advice to "re-cap" a radio this old. The aluminum electrolytic capacitors just don't hold up that long. Don't know how many of those are in this model, but I'm pretty sure a handful of them are in the mike audio circuits.

Just one problem. You won't find out if that's gonna fix it until you have changed all two or three dozen of those parts.

An experienced pro could zero in on the cap that's causing a particular fault. And changing just "the one" cap that causes today's symptom leaves the rest of them to come up later on. We call that "electronic whack-a-mole".

Do you have a way to check the mike on another radio?

Or another mike on this radio?

73
Yeah i know its old, thats a given Im looking for info on it as to where the modulation pot is located.
 
I have the same issue I've replaced all electrolytic caps and few polydips they were growing some kind of fuzz the mic is good checked all transistors all good still low modulation 3 watts dead key swings to 7ish if I scream into the mic
 

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