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FREQ. METERING DSO 068

Posted: Sat Jan 09, 2016 10:56 am
by termin
i have working DSO 068, but if i want freq. metering with help in built test signaling, what working on display oscilloskope (other menu point), i see nothing in menu freq. metering (input to same),
What is not correct?

Re: FREQ. METERING DSO 068

Posted: Thu Jan 14, 2016 11:48 am
by jye1
Sorry we are not quite understand your question. Did you mean you need frequency display on the same screen with waveform?

Re: FREQ. METERING DSO 068

Posted: Thu Jan 14, 2016 12:55 pm
by termin
I have good working Oscilloscope input and good Test signal output, but my problem is, if I connect test signal output in Freqency metering menĂ¼ point to oscilloscope input for freqency metering, not any signal.

Re: FREQ. METERING DSO 068

Posted: Thu Jan 14, 2016 7:02 pm
by jye1
When probe is floating or touched by finger can you see the display of frequency meter changes? If you have other signal source please try that signal to see if you can get correct frequency reading. You need to try different sensitivity settings at frequency measurement in order to get best (and correct) results.

Re: FREQ. METERING DSO 068

Posted: Mon Jan 18, 2016 3:48 pm
by termin
If I connect to input with hand, displaying nothing in Freqency metering mode, this is small signal, but big signal from Test signal output the same. This moment I can not working with professional signal source, later
possibile.
Other problem have, good Test signal in Oscilloscpe mode not pretty and with C5 and C8 cannot
change, not reaction.

Re: FREQ. METERING DSO 068

Posted: Mon Jan 18, 2016 3:49 pm
by termin
If I connect to input with hand, displaying nothing in Freqency metering mode, this is small signal, but big signal from Test signal output the same. This moment I can not working with professional signal source, later
possibile.
Other problem have, good Test signal in Oscilloscpe mode not pretty and with C5 and C8 cannot
change, not reaction.

Re: FREQ. METERING DSO 068

Posted: Mon Jan 18, 2016 4:07 pm
by jye1
Looks there was some problem with the channel to frequency meter. If you look at the schematic you can see frequency meter signal is taken from the analog channel output at TP4, through C19, U2A, and R28//C32 to pin 31 of U4. Please check all these components.

Re: FREQ. METERING DSO 068

Posted: Wed Jan 20, 2016 3:48 pm
by termin
Thank You for powerfull helping, , Freqency metering is OK, C19 was wrong change with new 10Mf 25V and working.
Small fault with non pretty osscilloscope signal form,with adjust capacitors C5, C8 not reactions, Too much signal form.

Re: FREQ. METERING DSO 068

Posted: Wed Jan 20, 2016 10:02 pm
by GTNMUDY
I found it very difficult to try to adjust C5 and C8 and look at the LCD screen.

What I did was use a mirror so I could keep the screwdriver in proper place without shorting out PCB and see the adjustments.

Note, The adjustment cannot be seen on the screen when you hold the waveform.

It took me about 4 times of adjusting the C8 and in Auto mode then hold to check the waveform...

Signal form from Test signal generator on Osscilloskope "To

Posted: Mon Jan 25, 2016 10:10 am
by termin
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?