|[AMRadio] PC-mount 5-pin tube sockets? |
k4kyv at charter.net
Fri Jan 12 14:50:38 EST 2007
I'm restoring and converting a Gates BC-1T transmitter which
has a seriously
damaged RF driver PC board. I'm making a custom-etched
replacement board, and
changing it to the 807 version while I'm at it. I've got all
except for any pc-mount 5-pin tube sockets for the 807 tubes...
anyone have two?
Although I'm not standing right here looking inside mine right now,
I'm pretty sure the board uses conventional 5-pin ceramic tube sockets, the
kind with the metal mounting ring, mounted on the PC board. The screw holes
also accomodate the Millen 807 shields, and wire is used to connect the tube
pins to the circuit board traces.
Maybe the original 6BG6 sockets were the PC-board types.
If I were going to replace the board, instead of etching a new PC
board, I would use a piece of aluminium sheet cut to the same size, and use
standoffs and terminal strips for the wiring, and use conventional metal
chassis type construction. Tubes-on-PC board construction is poor design
and nothing but trouble.
After I put my BC1-T on 160, I replaced the bakelite grid coil with a
piece of air core inductor stock (Airdux or Miniductor) that I happened to
have on hand. It is the same physical size as the original coil, and has
just exactly the number of turns needed to resonate on 160. My grid drive
increased from maximum 85 mills to the 833A's to 155 ma (plate off) and
135ma (plate on at high power), and neutralisation was more complete.
The 833A final was more stable after I altered the wiring so that all
components in the driver plate/PA grid circuitry in the rf section were
grounded to one common point on the chassis, instead of the way Gates did
it, using the nearest convenient grounding point for each component.
This message was typed using the DVORAK keyboard layout.
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