Re: All pain no gain

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jan Wagner by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jwagner-at-cc.hut.fi>

Hi,

> I need some help figuring out why my TC is not breaking out.

You have already tried tuning?

If your toroid is "too large" then adding either a bump of bunched up alu
foil or placing a long screwdriver or metal ruler on top will help. IMHO
there's no "too large" toroid - see
http://www.hut.fi/~jwagner/tesla/small_tc_output-tc2up.htm (runs nice with
enormously exaggerated toroid).

> Ground is ground right? Isn't earth ground the same as an RF ground?

For low powers, maybe 100W, this might just work out ok.

But, you will get a very nasty ground loop if you then connect RF ground
anywhere else than mains ground... Also the mains stranded wire is no good
at all for power RF. It is better to use mains ground just on the mains
side, and RF ground with proper RF grounding techniques to ground the
secondary base.

What I personally still haven't figured out  is where to connect the NST
center tap... ?!

* to mains ground => no galvanic isolation between HV secondary side and
primary side, 40kOhm wire resistance HV->GND not nice (8kV 50mA NST with
40kOhm secondary means 200 mA could flow).
* to RF ground => rf leaking to primary & secondary connected to high
current primary which makes it even more deadly if you do what you should
not do (in any) case i.e. touching the megawatt pulsed streamers
* to no ground => just nice, no probs, NSTs are well insulated to handle 8kV
between case and mains primary

> How often should the safety gap across the
> cap fire?  I adjusted the gap distance from loud blue light to none at
all.

At best it should not fire. Did you do it the right way - disconnect primary
capacitor and spark gap, then adjust safety gap to max length where it still
will strike over, and then extend it just a bit more so that it is 50-50 to
break over when flipping on/off the NST. Only then insert primary cap again,
and don't tamper with the safety gap after this.

greetz,
 - Jan