TVI/RFI Reduction. Empirical Results
More an FYI than anything else. I just re-fired my 6" coil tonight
after it had been down for almost a month (Had to rebuild a dropped
capacitor). The new cap is about .8nf more than the one it replaced.
This gives me a total of 16nf. Anyway, on to the results:
When I ran this coil before, I would trash television reception,
my wife was *VERY* unhappy about what it did to our 900Mhz cordless
etc. It was a *VERY* noisy coil. Since I was in overhaul mode anyway
with the rebuild of the cap, I did a complete overhaul of the
tank and supply wiring.
Old tank wiring:
Previously, the tank was solid 12AWG that ran point to point, fairly
long runs at points. Ground wire was 8AWG from the base of the coil
to a 'cluster' nut that all grounds connected to, and then 6AWG to the
ground rods. No chokes or resistors on the HV side, and a standard
noise filter on the line side.
New tank wiring:
The majority of the tank is now wired with 1.25" wide 1mil copper strap,
The Ground is the same strap to an acrylic header, which is now used for all
off support connections. The Tap line is now #10 stranded (was #12 solid).
I put the old aircore choke and resistors from my neon days on the pig,
to cut out kickbacks that were giving my new SG fits.
Now, I admit, I don't know which of these changes actually did the deed, but
the TV now only shows a couple of small interference lines, and the phone
doesn't even notice.
Moral of story: Watch the tank wiring. Chokes may yet serve a purpose on
pig powered coils.
BTW: I use a static gap on this coil as well..
Coiler, Homebrewer, Nerd. mycroft-at-access1-dot-net