FREQ. METERING DSO 068

Anything about this unique oscilloscope DIY kit
jye1
Posts: 1227
Joined: Wed Feb 20, 2013 4:58 pm

Re: FREQ. METERING DSO 068

Post by jye1 »

termin wrote:With mirror I have adjust signal form two display, C8 working , small "too much" have , but C5 has no effekt, have
big "too much" display, what my be wrong?
If you are sure C5 install good please check value of C4. If C4 is too big C5 will not be up to do the compensation. You can try disconnect C4 or replace with a smaller value if you have.
termin
Posts: 16
Joined: Thu Jan 07, 2016 2:49 pm

Re: FREQ. METERING DSO 068

Post by termin »

Problems with overrun in display Test signals in Osscilloscope mode solved,before was "too much", in place C5 and C8 new two
5pf to 50 pf trimmers good working, I have 100% signals.
staceygeek
Posts: 11
Joined: Thu Feb 11, 2016 8:33 am

Re: FREQ. METERING DSO 068

Post by 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.
staceygeek
Posts: 11
Joined: Thu Feb 11, 2016 8:33 am

Re: FREQ. METERING DSO 068

Post by staceygeek »

Just in case somebody wants to know the range of FC. My DSO068 measures frequency with accuracy 1Hz up to 8,2MHz. Above that the readings are inaccurate. There is TL082 opamp in the input circuit. It can has a bandwidth up to 3MHz, maybe replacing it with LM6172 (bandwidth up to 100MHz) can increase the range of FC up to 15MHz? The bandwidth cannot exceed the limitation of TLC5510 A/D converter (16MHz) anyway.
jaxllax
Posts: 14
Joined: Thu Jun 15, 2017 3:08 pm

Re: FREQ. METERING DSO 068

Post by jaxllax »

seguro son defectuosos c5 , yo tuve el mismo problema y resolví cambiando c5
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