"Back & White" First Light

["Kurt Schraner" <k.schraner-at-datacomm.ch> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi all!

Last weekend has been great! And we had the joy to have Finn
Hammer and family for a few days with us. On Sunday I had a small
Swiss-coiler meeting, together with him, Martin Damev and Andy
Saile. The coiling started on Saturday, setting up all the heavy
equipment in the backyard of my living place (I'm living in the
center of Basel-town). The neighbours had been warned from noise
and TVI by a leaflet, explaining what we were going to do, and I
had the good luck of no complaints.

The main data of my "Black & White" conventional hobby Tesla coil
setup are:

Top load: Toroid D=160cm(63"); d=40cm(~16")
Secondary: D=40cm(~16") x H=195cm(77"); 813 turns;
fo=119kHz/69kHz(with Toroid)
Primary: 9 turns 10mm(0.4") copper tubing, tapped at about 7.5
turns
Capacitor: 109nF, made of 3 Maxwell 300nF/100kV in series
Spark-gaps: - Static air-blast gap, as shown on my homepage
            - Finn's great "Millenium Lace" SRSG, operated at 200
BPS
HV-Transformers: 4 PT's 16kV / 100V (HV parallel-, LV serially
connected)
Ballast: 2 branches of a 3 phase variac, rated 380V/28A each
phase
Voltage control: X-ray variable transformer, rated 180V...400V /
120A (short time!) 

Even this size of coil is moderate, you need good friends (with
muscles!), ready to sweat, for setup. After measuring the
resonant frequency (with toroid) first light was started with the
static gap. After some tunig, we achieved a sparklength of about
2.8...2.9m (9.2'...9.5'), with the characteristic sound of a low
BPS (~100) erratic firing of this kind of gap, in Saturday
afternoon. 

Trying Finn's "Millenium Lace" SRSG was compelling! The dark of
the night was already here. The opportunity for me had come, to
learn, how this kind of unevenly spaced gap is to be set. The
result was amazing: Beautiful streamers developping and sparks
(to a grounded ladder point) increased suddenly to > 3m (10').
And the sound...!!! - More like a professionally controlled
device: as Finn mentioned: "As if you know what you're doing!".
Current and voltage, as well, were much easier to control
independently. The neighbours, watching from the windows of their
appartements, were asking: ...we missed the last, can you do it
again? - Sadly, we forgot to take pictures during this night's
sparking.

On Sunday, Martin Damev joined the group, and we had a lot of
coiler talks about different aspects, like DC PSU's,
transformers, RSG's etc. Continuing the experiments of Saturday
(between some rain showers) we confirmed the results of the day
before. And further tuning allowed to get a maximum sparklength
of 3.3m (~ 11') at a power input of 10kW. This is about an
average performance for the power, but, anyway looks like a
current european record of an amateur TC (...sure, for short time
only! - Greets to Alan Sharp, Marco Denicolai, Jens Raake, Stefan
Reissig and ?). It's to be seen as a preliminary result, without
taking the full capabilities of "Black & White", and optimum
synergy of all components. Also, "Black & White" might well
digest the doubling of power. But, anyway, for the first, we were
quite happy. The preliminary success wouldn't have been possible
without the brilliant performing of Finn's SRSG, and without the
help of my other friends as well. A big THANK YOU to all of you!
And my thanks to the list as well, for teaching me so many things
about TC's. 

Kurt

P.S. When I will have pic's, they will be shown on my homepage:
http://home.datacomm.ch/k.schraner/index.htm
Some photos of the building process of "B & W" can be seen under
'Equipment'.