Tnx. At this time I have a 25 Ohm 20W resistor between the output of the
rectifier/meter board and the input to the HV choke. It is one of the brown
tubular units (it is fairly long. . .). .'goes around that section of
chassis divider nicely. Considering all inputs, I have fused the bias
circuit with a 100mA fast blow in parallel with a MOV. Meters are diode
protected. I will get to the grid grounding this afternoon (do a quick check
back with the group for gotchas b4 firing it up. . .) and smoke test this
evening. . .should be interesting. .
-ap
> fault would interrupt filament, bias, and HV? I would probably leave the
> fan on a separate circuit. . . Art k3xf
That's one solution Art, if it accompanied by HV current limiting in
the form of a HV rated current limiting resistor in the HV lead.
Remember the HV fault inside a tube is normally from anode to
grid.
HV is an almost impossible thing to fuse reliably, so the best
option is generally to protect things with clamping diodes and add
enough surge resistance to prevent major fault damage.
73, Tom W8JI
w8ji@contesting.com
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