Hi Finn, all.
Finn, nice testing method. While it does make me cringe to look at it, it
makes me wonder if perhaps we try to coddle our MMC's against the nasty
secondary discharges too much. While I'll be the first to agree that
shooting it with the discharge directly isn't the best idea, I don't think
we have to worry about the caps as much as we do our xformers. True, the RF
will tear up the dialectric of the cap, and is just plain murdrous on an
NST's secondaries, but power-wise, the energy seems to be either in the
primary/caps/xformer or the secondary/streamers. You have losses, so each
xfer between the two has less energy that before, till quenching.
Sooo....no strike rail for me (didn't plan on one anywho). I'm more worried
about RF in the house wiring.
$8 for an MMC....figure you spend ~$30 on it, and it'd be bulletproof.
And imho, I believe my caps take a worse pounding when I hook it across the
bottom of a jacob's ladder for grins...never run it long, but *wow*, what a
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, May 10, 2000 7:42 AM
Original Poster: "Finn Hammer" <f-hammer-at-post5.tele.dk>
A rubar is, I believe, an Australian bumper, designed to protect the
vehicle against cangaroos, when they get hit at night.
Also a term used during WW2, to describe, or nickname, materiel that was
unnecasarily heavy built.
Perhaps we can also start to call the strike protection ring for "RUBAR"
I put my cheap coil up for testing the MMC for direct strikes, so that
the discharge was a powerarc to the midle of the capacitor, and it ran
along just fine!
This has been discussed before, I just felt like putting up some
pictures to prove it
I tested the coil like this for a couple of minutes, and the cap is
The coil is powered by 2 MOT`s, ballasted by a 65mH choke, the sparkgap
is 2 pcs. tungsten/torium rod in copper details. Cap is 8 56 nF/1600 VDC
Phillips 376 series, 4 rows of 2 caps. They usually last 15 minutes.
Cheers, Finn Hammer