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Sound Technology 1000A Stereo Generator problems

Hi,

Has anybody ever run into a problem with this unit, whereby the 19kHz pilot level is intermittent? It doesn't seem to be a thermal problem, and I have cleaned the switches and controls. I don't know if the phase adjustment pot on the main board might have a problem. Looking at the 19kHz signal on an oscilloscope appears to show a steady state signal level; however, the modulation meter on the RF generator itself shows an erratic level, suggesting later stages in the signal chain. Can anybody help?

Pete Gianakopoulos

Reply to
Pete KE9OA
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If your interested In the 19khz signal and it looks ok at the output of the generator if thats what your saying then wouldn't you check the modulation producing circuits or the meter chkt itself.

Reply to
mark

it might be time to replace some caps and do the maintenance that is usually needed on old test equipment. check solder joints, broken wires, etc.

look at the left minus right signal at the output with the 'scope. use a low audio frequency like about 100 Hz. if it looks like a string of beads (double sine wave) you are in pretty good shape. expand the 'scope to view the crossover point closely, the waveform should be symmetrical.

if you are referring to a jitter that occurs when audio such as music is fed to left and right it could very well be a normal situation. the demodulated FM pilot usually shows some jumping around even on the some of the finest broadcast generators that are made.

Reply to
TimPerry

Hi Tim,

Thanks for the insight. The erratic indication on the meter shows up with the 19kHz only; this is with no other audio input, including the internal oscillator.

Pete

Reply to
Pete KE9OA

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