Re: Bypass caps and Neons
From: Mark S Graalman[SMTP:wb8jkr-at-juno-dot-com]
Sent: Tuesday, December 09, 1997 4:31 AM
Subject: Re: Bypass caps and Neons
The concept of a "lossy" bypass is incorrect,
the more "lossy" a bypass, the less its ability to
bypass. I would NOT use larger than a 500 pf, and
install the bypasses right at the transformer end
bells, use about a 1K ohm 25 watt WIREWOUND
resistor in each transformer lead between the
choke and the transformer. Lastly, make sure
the combination of your choke and bypass cap
doesn't resonate on or near the fundamental
or a harmonic of the coil operating frequency.
Mark Graalman, Toledo, Ohio
Member: Society of Telecommunications Engineers
On Mon, 8 Dec 1997 20:59:09 -0600 Tesla List <tesla-at-pupman-dot-com> writes:
>Reply To: baumann-at-proton.llumc.edu
>Sent: Monday, December 08, 1997 7:16 AM
>Subject: Bypass caps and Neons
>Looking for advice from more than one source:
>I am getting conflicting advice, and so I am asking here.
>Does one, or does one not, need bypass caps when using neons?
>Currently, I am using a pair of bottle caps as bypasses, and I had
>just made a couple of 500pf poly caps to replace them. Then I found
>a message from Richard Quick, stating that bypass caps should be
>very lossy WRT HF energy., so I'll use these caps in parallel with my
>6nf cap on my coil, and stick with my saltwater caps for the bypass.
> I have also gotten advice to just avoid the caps altogether, as you
>fry a neon with unwanted resonance.
>Needless to say, I am confused. Any light that could be shed on this
>would be very welcome.
>Particulars on the coil in question:
>Power: 12KV 30ma NST controlled with 140V/10A variac.
>Choke + Resistor: 3.2mh air core [6" of 28g on 2" form], 1K 50w
>wirewound resistor [ for another 2.7 mh of inductance BTW]
>Tank circut: 12G wire for interconnect, 9 turns 1/4" copper pipe,
>starting at 5.5" diameter, with 1/4" spacing, 6nf homebrew poly
>capacitor, 7 element RQ style static gap, spaced at .030, total gap
>Toriod: 3" x 12" (pie pan + 3" flex ducting)
>Michael Baumann Optivus Technology Inc.|Loma Linda University Medical
>San Bernardino, California. (909)799-8308 |Internet: baumann-at-llumc.edu