Re: which tubes to get at hamfest?

Tesla List wrote:
> Original Poster: "Jeff Corr" <corr-at-enid-dot-com>
> I've seen on the list over the last few days, and on webpages that
> it is possible to make tube coils with the following tubes :
> 803
> 811
> 811a
> 813
> 833a
> Are there any other tubes that are popularly used for tube coils that I
> should be an eye out for at this hamfest?


I also highly recommend 572B/T160L.  It is an 811A on Steroids:

Vbb ~ 3kV
mu  ~ 160 (for all intents same gain)
Ibmax ~ 275mA
Plate P max  160W (vs 65 for 811A)

Note: tube as graphite plates, roughly equivalent to 2.5 811A's in one
glass envelope, same pinout, same fil ratings; tube is a direct one for
one swap with an 811A in most applications.

I ran a push-pull system using two tubes in a hartley oscillator at
Ed Wingates 1997 Teslathon at 1.4kW input (level shift) and was getting
12-13" streamers (~4.0kV pk).  Upgraded to 2.5kV industrial MOT and at
6.8kV pk in ( :^O ) was getting 18-20" streamers before tubes blew...
with 2.5A pk at 6.8kV pk push pull nearly 50kW peak plate input!!!

With 1.4kW input, tubes (2) were BULLET proof.


Chesterfield, VA. USA