On Wed, 1 Mar 2017 13:54:34 -0500, Michael Black wrote:

On Wed, 1 Mar 2017, Michael A. Terrell wrote:

wrote:
"It all about raising up the plate supply voltage while keeping the screen
supply under 400V - plus matching the load correctly. "

Seems to me to would have to load is pretty heavily, not just to get the
power, but also to try to keep the plate volage down. If you go to 2X 700
volts, it might not be a matter of the tubes, it might be the tubes
sockets.


They used a lot of ceramic tube sockets in transmitters.

ANd the really good tubes had plate caps.

Michael

I can relate to using ceramic sockets, because the standard ones would
likely burn up from such high voltages.
* What are the standard sockets made out of anyhow????

Considering the closeness of the tube socket pins, I could see where
there could be arcing between pins at voltages that are or exceed 1000V.
Plate caps eliminate that problem. However, I would assume that the wire
going to those plate caps would need to have insulation capable of the
voltage, and where they go thru the chassis, would need grommets that
can handle the voltage too. Not to mention the connections below the
chassis such as terminal strips.

I have not worked with any voltages exceeding 1000V (except the HV in
the old tv sets). But since I am on a farm, I know what an electric
fencer can do. If a fence wire gets too close to a tree (for example),
it will snap and shoot a spark a half inch long, or longer. Most of
those fencers are around 5000 V. Those fence wires are all run on
porcelin insultors. (although there are now plastic ones that work as
well).

I have felt them fences far too many times too..... I have been
literally knocked down from them more than once, if I was well
grounded.... NOT FUN.

Fortunately those fencers do not kill a person or animal (or we would
not use them, since livestock are expensive and dead people are not a
good thing). The voltage is high, but the current is low. (and it
pulses).

Anyhow, while I have not done it, I am sure building transmitters (or
anything else) using those high voltages, require special components and
wiring, which in itself requires special knowledge.