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Re: Primary Q's and Spark Gaps

Hi all,
         Ed Philips wrote....

>     I have determined that, while the 30 seconds of
> "growth" time was a correct observation, most of the
> effect appears to be due to change in primary tuning
> due to (warming up) of the ceramic "door knob" capacitors
> I am using.  Can't detect the warming by touching them,
> but once they are (warm?) the sparks increase to maximum
> length in a matter of a second or so after I apply the
> power.  Also, in this particular case, the primary frequencyh
> frequency measured with an absorption wave meter changes from
> about 260 kHz to 280 KHz, which goes along with the capacitance
> change.  More if I can measure more.

Interesting - what is the secondary frequency? I had the germ of an
idea after initially reading this that I was going to test in single
shot mode. It occurred to me that the effect might be related to
spark gap heating (better ionization, lower resistance?). The idea
was to measure its Q cold using the standard ping test, then heat
the electrodes with a blowtorch and remeasure. I'll try and find time
to do it today. (One secretly hopes this thing might point the way
to better primary performance).
     On a slightly related topic....
a cursory glance at the formula Mark Barton posted describing
the secondary output waveform suggests that the "hump" phenomenon
was actually the split frequencies beating. I haven't done the maths
on it yet but it is going to be very revealing as he says. I already
had a look at frequency relationships but rather hastily and without
a great deal of solid measurement.

Malcolm