Re: Tube coil related questions

[cwillis-at-guilford.edu (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Thanks John, David, Chris-  you all pretty much indicated that excessive
current (probably from charging the capacitor) is causing the diodes to
fail.  I have forgotten what the "current rule" for diodes is (you take the
rated current and multiply by a number to give an appropriate safety
margin) and as a result I didn't even think that current handling was a
problem.  I was putting oven diodes in series to try to improve things.

I am probably going to include the resistor divider just in case there are
voltage problems also, but I'll go ahead and build some diode strings.
Hosfelt has a better deal than my other suppliers for the 6-amp diodes- 32
cents each. 

My "improved" 833 A coil will have a double-decker pancake primary with
variable coupling between the two flat spirals so I have more flexibility.
I just made another secondary today, this time I actually washed the grime
off my PVC pipe with acetone, and used non-water-based polyurethane coating
rather than shellac.  I expect better results, and I'll let y'all know if
my problem comes up again.

Thanks,

Carl