terryS ) writes:
On May 12, 7:56 pm, "Antonio Vernucci" wrote:
Thanks for answers

Tony I0JX

But I've also read that the variuos 'command' receivers (BC453, 454
etc,) will work well with much lower B+ voltages.
Which are much kinder on the 60 year old decoupling capacitors etc.
can't remember the value but could it have been as low as 120 volts
DC?

I can't say that I've seen that applied to Command sets specifically,
but it's not an unknown concept.

IN 1970, there was a two-part article by Fred Brown about updating an
HRO receiver. He replaced the full size tubes with more modern
equivalents, did some other changes, and ran it at a lower voltage than
originally. He gave all kinds of reasons for the lower plate voltage,
and mentioned that the Collins S-line receiver used lower plate voltage.

I think it was that article where he said the only disadvantage was lower
audio output.

Michael VE2BVW


Cos it occurs to me that one could use a 150 volt gas regulator tube
(OD3?) on the output of a power supply to achieve that?

Michael Black wrote:


IN 1970, there was a two-part article by Fred Brown about updating an
HRO receiver. He replaced the full size tubes with more modern
equivalents, did some other changes, and ran it at a lower voltage than
originally. He gave all kinds of reasons for the lower plate voltage,
and mentioned that the Collins S-line receiver used lower plate voltage.

I recall that at the HAMfest at Birmingham (AL) several years ago
(possibly as many as 15) some chap had a BC-348 that he had converted to
solid state. All of the tubes had been replaced by transistors - and it
worked pretty well - at least there in the Jefferson Convention Center.

I've thought about trying the same with one of the arc5 receivers - just
never got around to it. Dave Stinson would probably be one to ask about
such a project - Dave- got your ears on?

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Randy or Sherry Guttery ) writes:
Michael Black wrote:


IN 1970, there was a two-part article by Fred Brown about updating an
HRO receiver. He replaced the full size tubes with more modern
equivalents, did some other changes, and ran it at a lower voltage than
originally. He gave all kinds of reasons for the lower plate voltage,
and mentioned that the Collins S-line receiver used lower plate voltage.

I recall that at the HAMfest at Birmingham (AL) several years ago
(possibly as many as 15) some chap had a BC-348 that he had converted to
solid state. All of the tubes had been replaced by transistors - and it
worked pretty well - at least there in the Jefferson Convention Center.

Hank Cross, W1OOP, had an article in Ham Radio magazine in 1969 about
converting one to solid state. It's always interesting how that sort
of conversion went, becuase different people had different philosophy.
Some try to make universal type solid state "tubes". Others build
modules that fit the specific tube socket, but don't tamper with the
existing circuitry. Others, made modules but did do some fiddling
with the existing values.

Hank Cross's philosophy was to basically treat it as a chassis
with coils and capacitors, and hence wasn't stuck with trying to retro
fit solid state devices. It was a mixture of mosfets, bipolar transistors
and ICs. Of course, he also used the opportunity to add some things
he felt missing, like an FM detector (he did a lot of VHF work) and
I think he even made it double conversion.

Michael VE2BVW

I've thought about trying the same with one of the arc5 receivers - just
never got around to it. Dave Stinson would probably be one to ask about
such a project - Dave- got your ears on?

best regards...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com