RE: Re. need some input
Parallel with SG??? Don't you mean to ground from each leg? (in parallel
would work for those of us using non-centertapped transformers)
Coiler, Homebrewer, Nerd. mycroft-at-access1-dot-net
> -----Original Message-----
> From: Tesla List [mailto:tesla-at-pupman-dot-com]
> Sent: Friday, March 19, 1999 6:49 PM
> To: tesla-at-pupman-dot-com
> Subject: Re. need some input
> Original Poster: Gary Lau 19-Mar-1999 1601 <lau-at-hdecad.ENET.dec-dot-com>
> >Original Poster: "art" <ignatz-at-datasync-dot-com>
> >my first tc was a bugzapper getting 2 1/2 inch sparks i was amazed at the
> >results i got with no planning! the next one will have some design
> >configuration to it. i just wanted it to work good the first
> time with my nst.
> >and not fry anything up :-)
> >well i have a nst on hand 12k/30ma. i wanted to see if a few
> things mattered
> >1, safty gap setting should be gaped just far enough that there
> is no spark,
> >and between the terminals should be a good rf ground.
> Correct. Make sure the gap is set with the tank circuit disconnected.
> >2,do i need more than one set of gaps?
> For the safety gap, no. Just a single one as you described above.
> >3,should the safty gap be as close as possable to the xformer?
> Yes, reasonably so, though I doubt several inches makes any difference.
> >4, is it a good idea to shield the xformer?
> You mean magnetic shielding? No need for that. It should be shielded
> against strikes from the secondary though.
> >5, can i put the xformer to close to the coil?
> I have mine about 15" below the primary. Theoretically there will be
> some eddy current losses, but I doubt it will make an observable
> difference in performance.
> >SPARK GAP
> >is there a good configuration to start with.
> >more than one gap?
> I've had good results with both single and multiple gaps. But in both
> cases, it's VITAL to observe that the electrodes be rounded and smooth on
> all arcing surfaces, and that the arc channel have forced airflow through
> it. Don't even bother if there's no airflow, performance will be
> terrible. A good starting point is a multi-gap cylinder, a.k.a. the RQ
> or the TCBOR gap.
> >RF CHOKES
> >do i really need them?
> >whats a good Mh/Uh
> You will no doubt get several different answers to this. I say no,
> chokes in a protection network eliminate one problem (they're good at
> filtering out the tank frequency) but create another comparable problem
> (they will ring at their own self-resonant frequency). Instead, use just
> an R-C network in each leg of the NST. C=300-800pF in parallel with
> safety gap, R=1K-10K, 50-100W between NST terminal and main spark gap.
> Regards, Gary Lau
> Waltham, MA USA