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What I did this sunday
Today was the first firing of my new rotary, which I posted url`s for
later this week.
It was also the debut of the fiberprobe measuring system.
I saw the primary ringdown on the scope, triggering on the ringdown
itself, it stood as etched on the CTR, at 20 kV/div. and I never felt
coiling quite as intensive and thrilling as I did that moment. The scope
is a gould 20 MHz positioned only 12 feet/4 meters from the coil, and It
lasted the session out, without a hickup. Didn`t quite have the nerve,
or saw any reason to apply the Tektronix 485. Didn`t get any pictures,
because the time available was limited, and I ended blowing up a fault
current relay, so that the whole supply to the lab was uncerviceable.
Running the coil with a multigap rotary is an involving task, but with
this initial test, where the coil was run mainly on 2 elektrode pairs,
at 200 bps, i was convinced, that it is the way to fly. The sound from
the gap was not much louder than the series static gap that I used
before, and I take this to mean, that the losses in it are not
extraordinary. The ability to tune the primary charging circuit to a
steady _tone_, where not one single electrode presentation is missed,
and every bang is equal in size, is no doubt addictive.
The convenience of using a variac for current controll, should not be
underestimated, it is just so much easier, and should be the primary
recommendation, really, because it is the best.
Also a 3 ohms series resistor in the powerline, thanks to Dr. Resonance
for consistent mention of this element for smoother running.
The quench at all power levels, max.ìng out at 5 foot streamers, was a
6`th notch, and I was surprised, and releived to observe the benign
appearande of the ringdown, no nasty spikes to opserve, sofar. I only
managed to reduce the initial coupling setting of 0.18 to 0.16, before I
had to stop, but that made no apparant change in the ringdown.
The impression I got was of a streamer well integrated into the
secondary circuit, as a load that lets the input power oscillate over
longer time than I had thought probable.
Like I said, we ran out of time, the days are only 7 hours long here,
now it`s winter, and the lab was cold, so the ambitious goal of
producing a full set of scope pictures during this sunday were not
fulfilled, and I made some grounding related goofs, but this was the
most rewarding day in my 7 months long time as an active coiler.
A warm thanks goes to all of you who chipped in, to make this possible.
Cheers, Finn Hammer