[Amps] Breakdown tester, RM 215 L2

[Denis Jackson]

I bought this years ago, and have recently been using it to check components
for my new amplifier project.  It's branded 'Avo' but I believe they were
sold under a number of other brands too.

 

Unfortunately, it now seems to have developed a fault, and I don't think
it's generating any HV at all now, on either AC or DC.  I wound the voltage
right down, using the front panel control, connected my (1000 V max) test
meter to the HV probe and earth, and whilst I do get a reading, it rose to
no more than 250V, with the voltage control subsequently turned to maximum,
which should be producing 12kV DC.

 

Does anyone have a circuit diagram or manual for this that they would be
prepared to scan for me?  If anyone knows this piece of kit and has any
ideas as to where I might start working out what's wrong with it, that would
be useful too.  I don't have anything to measure the HV directly, but I have
measured the resistance of the secondary winding. There are two taps, 4kV
and 6kV.  Measuring from 0V (which appears to be above chassis ground), I
have 43k ohms to the 4kV tap, and 60k ohms to the 6kv tap.  This seems very
high to me, but perhaps not, given the ultra-low current that this device
produces?  You will gather, I have no experience of such equipment.

 

Suggestions or advice much appreciated.

 

73

 

Denis MW0CBC / GW8OQV