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204B problem in the 10k range


 

hello friends,

I have a little problem in my 204B Oscillator.

This apparatus have a selfmade stabilizes PSU in the back, the DC voltage is near to perfect.
Ranges? x1 / x10 / x100 / x1k? works accurate in frequeny and signal level. OK

Range x10k:

from 5 to 7 there is no oscillation. At 8 it starts, with very low output, the frequency is around 3% higher then the button scale.

In center of the button scale it work OK, but the frequency is still around 3% more then on the button.

From 20 up the signal level goes lower and lower.

So I have a problem in the 10k range parts.

How to continue ? application is here.

Martin


 

Hi Martin,
did you check the usual suspects (electrolytic capacitors) already? Also, if I understand correctly, the power supply is not original. Did you check its output voltage behavior when tuning through the frequency ranges? There might be an unintended interaction between the PS and the oscillator, causing this behavior.
Regards
Chris