John Bartley ) writes:
I'm not sure how to do the tubes in a DB format, but everything else
should be straightforward.
I'm not sure it completely translates to tubes, since "dead bug" seems
to suggest everything mounted on one side of the circuit board.
But people did take advantage of copper circuit board in tube circuits.
Invert the chassis, and use it merely to protect the circuitry.
Sometimes the tubes were mounted with a bracket (made of more circuit board,
and even soldered to the main board) on the copper side of the
board, the most obvious times were when the tubes were Nuvistors, but the
scheme was used sometimes when compact construction was desired. But usually,
the tube sockets were mounted in holes in the circuit board, and if aluminum
is easier than steel to work with, copper circuit board is even easier.
Once the tube sockets were in place, then everything would be wired up
as usual, with the difference being that it was really easy to drill a
hole for a coil, and every time a ground point was needed, it was a simple
matter of soldering the lead to the copper circuit board. No high wattage
iron or gun is needed, since the copper isn't really thick. If you need
to change things, it's relatively easy to disconnect that ground point,
and unlike with old methods, you don't have an extra hole if you do change
it. Leads could be short, because you could make ground connections where
they were needed rather than where there was a ground lug.
Because of the tube sockets, this tended to be a bit more formal than with
solid state devices, but it was still a neat way to build, and some of the
most busy builders used it because they were always trying to improve things.
Frank Jones did a lot of this sort of thing, at least after Nuvistors came
along. Even before that, many of his converter projects were built on an
inverted chassis, with a piece of aluminum for mounting the parts rather than
circuit board.
Bill Hoisington K1CLL wrote tons of articles in the sixties ane early
seventies, and pretty much everything was build on circuit board. He was
not concerned with looks, and the few times there were photographs, they
did look very "dead bug" like. He even built an amplifier with a 4CX250
or such on copper circuit board.
Michael VE2BVW
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