tomizett
Active Member
Hi All,
I wonder if anybody might be able to help me repair my Feedback FG601 function generator? Chiefly I'm looking for schamatics or a service manual, but google hasn't found any for me. Does anyone know where I might find this information, or does anyone have experience working on these machines themselves?
For the sake of completeness I'll give a rundown of the fault, which has been intermittent for a while but has now become a perminent failure. It produces no AC signal on either the main output or the TTL. You do, however, get DC offset control and an "additional" DC signal which varies with the output level control. The polarity of this "additional" DC changes depending upon the selected waveform. When the fault was intermittent, the instrument could sometimes be coaxed into working by switching between frequency ranges or waveforms.
Given these symptoms, I'm pretty confident that it's the main oscillator at the heart of the instrument that isn't oscillating - rather it's just staturating against one rail and sitting there.
I've had the thing apart previously and, suspecting a machanical problem, cleaned all the switches, reworked a lot of solder etc. I wasn't able to track it down to any kind of mechnical factor, but that would still seem a feasable cause (maybe a hairline crack in a trace etc).
There is a surprising amount of stuff inside theis little green box, so any information you may have would be greatly appreciated!
I'm going to take the lid off it again now...
I wonder if anybody might be able to help me repair my Feedback FG601 function generator? Chiefly I'm looking for schamatics or a service manual, but google hasn't found any for me. Does anyone know where I might find this information, or does anyone have experience working on these machines themselves?
For the sake of completeness I'll give a rundown of the fault, which has been intermittent for a while but has now become a perminent failure. It produces no AC signal on either the main output or the TTL. You do, however, get DC offset control and an "additional" DC signal which varies with the output level control. The polarity of this "additional" DC changes depending upon the selected waveform. When the fault was intermittent, the instrument could sometimes be coaxed into working by switching between frequency ranges or waveforms.
Given these symptoms, I'm pretty confident that it's the main oscillator at the heart of the instrument that isn't oscillating - rather it's just staturating against one rail and sitting there.
I've had the thing apart previously and, suspecting a machanical problem, cleaned all the switches, reworked a lot of solder etc. I wasn't able to track it down to any kind of mechnical factor, but that would still seem a feasable cause (maybe a hairline crack in a trace etc).
There is a surprising amount of stuff inside theis little green box, so any information you may have would be greatly appreciated!
I'm going to take the lid off it again now...