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Old 2nd Dec 2017, 8:15 pm   #1
SeanMcK
Retired Dormant Member
 
Join Date: Sep 2008
Location: Londonderry, Northern Ireland, UK.
Posts: 58
Default Can the voltage at the PF terminals of an Avo Model 7 Mk2 be used as a diagnostic?

A while back I had either an Avo7 or an Avo40 with dicky AC side, it's fixed and I don't remember the cause but during the investigation/repair I had the thought that a DMM across the PF terminals would surely see virtually the full working output voltage of the transformer.
Am I up a gum tree?
I have just got a Model 7 that reads low on AC V. I have had a play, first with 1 and then 2 Avo M200x's across the PF terminals.
I didn't take note of the actual indicated voltage on the 1st DMM but it was over 0.5V, adding the 2nd caused a 3mV drop in the reading given by the 1st and there was no discernible change in the reading given by the Model 7.
Putting 100V across the the Model 7 on the 100V range gave a reading on the Model 7 in the high 80's and the DMM's across the PF terminals showed around 1.149V ( one is TRMS and the other average? responding).

I am curious if measuring the voltage across the PF terminals has any diagnostic value?

Thanks
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