Re: Tube TC

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: robert heidlebaugh <rheidlebaugh@xxxxxxxxxxxxxx>

Dan: Sorry for my delay in answer  . The armstrong Oscilator has the highest
power and least cost/simplisity. It is least stable. The Hartley requires a
tapped coil and not all the power is carried by the coil some of the power
is diverted out of phase back into the tube.. so 100% of the power is not
available to the secondary coil.  The Colpitts circuit has a tapped
capacitor and very low power. Tuning requires eleborate circuitry. The
Arrmstromg circuit requires a low parts count and very low cost. Your coils
are made of wire . Tunning requires one capasitor and grid bias uses two
resistors and a potentiometer , sometimes a capacitor of low voltage/cost.
The tube can act as its own rectifier with AC to the plate as I  use. so
that  circuit is not there. My tube tesla coil has been in use since the end
of WII with day after day of continuous use. All I have ever replaced is the
tube and I have had to re shelack the coil from time to time as modern
plastics were not available when built and wood and cardboard coil  formes
age and glue turns to dust.. To this day I use it to power my Xray and other
high voltage equipment. I also have spark gap coils , but my first VT TC is
still in service to this day.
  Robert   H
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> From: "Tesla list" <tesla@xxxxxxxxxx>
> Date: Wed, 12 Oct 2005 18:09:34 -0600
> To: tesla@xxxxxxxxxx
> Subject: Tube TC
> Resent-From: tesla@xxxxxxxxxx
> Resent-Date: Wed, 12 Oct 2005 18:12:33 -0600 (MDT)
>
> Original poster: "Dan" <DUllfig@xxxxxxxxxxxxx>
>
> All:
>
> I have been looking at different VTTC's, and noticed that most all of
> them are variations of the Armstrong tuned grid oscillator. Nowhere
> is it explained the merits of using such an oscillator. Why isn't the
> Colpitts, for example, used? what is the advantage? or drawback? has
> anyone built a VTTC that is wired differently?
>
> It would seem to me that a colpitts oscillator would give you a tuned
> primary; since the DRSSTC coil works so much better on account of
> having the primary tank tuned, wouldn't a tuned primary benefit a VTTC also?
>
> By the way, I just bought a 833a tube on ebay, and plan on building a
> coil around it.
>
> Dan
>
>
>
>