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vintage_8bit · 24th May 2020, 4:02 pm

I have checked both my DVM's they seem to measure correctly when set to DC on a half wave rectified voltage (.45) There is a discrepancy when looking at the same waveform on ac...... With 200V RMS and a silicon diode I get 103V on my keithley 2000 and 111V on my cheap Digitek handheld DVM. I used this for my measurements in post 9 so I should perform the tests again with the Keithley.

Going back again through the cal procedure, I have noticed that RV6 has to be set to max to hit the set mark. I will investigate this as I assume this is not desirable.

In post 6 you will see the values I obtained from just using bench supplies on the EL84. As you mentioned oscillation can happen, when I first tried this I had trouble with it oscillating. The cure was nice short wires. You can see the results were similar to the 163.

24th May 2020, 4:02 pm	#11
vintage_8bit Heptode Join Date: Feb 2013 Location: Rainham, Kent, UK. Posts: 525	Re: AVO VCM Mk 3. I have checked both my DVM's they seem to measure correctly when set to DC on a half wave rectified voltage (.45) There is a discrepancy when looking at the same waveform on ac...... With 200V RMS and a silicon diode I get 103V on my keithley 2000 and 111V on my cheap Digitek handheld DVM. I used this for my measurements in post 9 so I should perform the tests again with the Keithley. Going back again through the cal procedure, I have noticed that RV6 has to be set to max to hit the set mark. I will investigate this as I assume this is not desirable. In post 6 you will see the values I obtained from just using bench supplies on the EL84. As you mentioned oscillation can happen, when I first tried this I had trouble with it oscillating. The cure was nice short wires. You can see the results were similar to the 163.