JYE Tech Forum

There was a modified diagram published recently that showed the current rating as 0.5A. Search the recent posts.

Wasn't as recent as I recalled!

viewtopic.php?f=18&t=1266

OK checked my two DVMs and they are about the same. If someone grabs a old analogue multimeter to do these measurements they might want to check whether or not the meter will put excessive voltage on the chosen resistance range.

Cheers,
davef

What voltage does your multimeter present to the circuit under test on the highest resistance range?

Dave

I see you have it set for maximum sensitivity and maybe what you are seeing is just some leakage of the input signal though SW1A to the input amplifier U2B. It would be handy to trace the calibration signal through to U2B, however needs another oscilloscope. Maybe, show pictures in the AC and DC pos...

viewtopic.php?f=18&t=712

The search function didn't help but I could remember that it currently was not used.

I am just checking that you have performed the "0V Line Alignment" as in User manual page 3.

If you can't get a change in the screen readout between X2 and X5, maybe checking VSENSEL2 on pin TP8 might help.

Good luck!

On second thought ... on the 10mV range the input impedance of the system is very high so maybe an option is to make your own external divider, say 20M Ohms with a 20K shunt and probably a trimmer cap to give you a "10V" range.

Effectively making your own 10X probe.

How can I go about attenuating the signal? By buying a proper 10X probe Will a pair of 100K resistors as voltage divider work (with input set to 100x on the scope)? Not very well. In input impedance on that range is 100K, which will change the divider ratio significantly. Will I need to attach any ...

Have you tried changing the input selectors switches for different sensitivities?

Can I assume that you can hear this tone easily on a pair of headphones? If so, have you a good connection from your sound source to the 'scope?

Appear to be sound modifications.

Did you find the sub-standard "TL084" by testing its slewrate?

I assume you are using the latest firmware, correct?

Thanks for providing the schematic and photos.

davef