I remember seeing something like that around the '60s, in QST I believe.
It was built into a suitcase by a guy who traveled a lot, to be used in
hotel rooms. (Imagine the RFI problems!) I don't think that particular
one was using 807s, though -- I believe it had some later type of sweep
tube that wasn't as tall.

The 807 was, incidentally, used as a sweep tube. In the middle '60s I
worked on heavy ground radar (mostly '50s vintage), and the 12 inch PPI
(round) radar scopes used push-pull 807s for the deflection. I once had
a huge box full of 'em too, but they had to go when we moved from Alaska
to the lower 48. They're probably still up there somewhere. . .

Roy Lewallen, W7EL

Philip de Cadenet wrote:
Ken,

I recall one amp used a voltage quadrupler to get 600 volts from
the 120v ac line and had 10 tubes with the heaters wired in series.
One tube was a driver, and 9 were grounded grid finals.
(A bit of a shock hazzard perhaps.)


I've seen something similar here in the UK 20+ years back and remember
the amateur who built the thing. I think he was playing around the Kw
level and with no transformers in sight.

We do have a head start on you fellas with 240v @ 50Hz :-)

A 'bit' of a shock hazard is kind of an understatement don't you think.