GS wrote:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3064839871


Please - I almost never post Ebay stuff in this group, unless it very
specifically relates to the homebrew crowd.

I'm posting just cuz you HAVE TO SEE this piece of work. LOTS
of photos - possibly the most hideous homebrew amplifier ever!
If the guy didn't die testing it, I'd be surprised....

Again, sorry for the Ebay post. Don't bid - just look. It's amazing

GS


Looks like this amp was designed for 3 811A's (three sockets), maybe he
dropped
one of the tubes?

BTW I built an amp almost as ugly about 15 years ago using a pair of
4-400A's.
Mine was at least safe, and it even worked on 80-20, above that the tank
was not optimal and it worked poor. On 80 it tuned as broad as a barn, but
I've seen SB-200's do that too. Mine was built in a pair of boxes one
on top of the
other that came out of a surplus computer system. The top box was the
rf box (used
to hold the disk drives) the bottom box was the power supply (used to
hold the rest
of the computer) so it looked like a sick Henry 2K. The only power
transformer
I could find had a 120v primary, but it was good for a real 2kw. (when ever
I tuned up for more than 20 seconds I blew the 20A breaker). The plate
supply
was plugged into one outlet on it's own line, the relay and filament
supply was
plugged into a second outlet on a different line. I had a FWB rectifier
using
1N4007's, each leg had 10 diodes in series with equalizing resistors and
caps
(WAY over built). The secondary put out almost 3kv no load, so the
tubes were
running a little over 4kv. The filter was 10 400uf 450v computer grade caps
in series, with 20k resistors across each. A real MONSTER of a supply.
There was a power resistor in series with the primary that was shorted
out by a relay
across a sensing resistor in series with the primary as well. This gave
the HV
supply a soft start so the capacitors charging wouldn't zap the diodes.
Wish I kept a photo of my Frankenstein machine.