Adjustment of Compensation capacitors.

[jye1]

Check their connection and values. Value is not easy to verify if you do not have cap meter. But you can try by adding another cap in parallel to the suspicious cap to see changes. So you get idea about the cap is good or not. If you do not have small caps you can replace with two segments of twisted magnetic wires (or small hookup wires). For a few pF you can cut two wires to 3 - 4 cm and twist them together. Solder the two wires to the place of a cap. If you want larger capacitance twist them tighter. If you want smaller capacitance cut them short. Seal the with wax or silicone when you find the best value.

[gregma]

Same exact problem here. Any way of troubleshooting without having to remove the capacitors and trying different values? I wouldn't expect to have to try and redesign the circuit to make it work. All I get is "Not Enough". Adjusting C8 does nothing to affect the waveform.

Please check C6. Small C6 or large C7//C8 will result "not enough". On the opposite, large C6 or small C7//C8 will result "too much".

I replaced C6 and that solved the problem. Thank you!

[staceygeek]

I have successfully solved this problem by replacing C7 with 100pF after this was done adjusting C8 trimmer changed the waveform of the test signal. I also replaced C5 trimmer with 22pF cap and got a good square waveform of the test signal. Maybe it helps somebody.

[venca666]

C7 change to 330p and C6 - 68 to 180p and it's ok

[reddog]

Im reading the comments here about this adustment. Change c6 or c7 to this or that. My question is why should I have to change anything? Shouldn't all the components be correct out of the box?

[AlexTzv]

I had to replace C7 to 68p. Now all is well.