"Uncle Peter" ) writes:
wrote in message
...
On Fri, 27 Jul 2007 01:43:09 -0700, Clayton wrote:
Radio Amateurs Handbook any copy printeted between 1963 to 1970.
Also back issues of QST for that era.

A tube TRX for SSB will minimally be around 11 tubes or more and not
simple. Just finding items like the power transformer will be a
challenge.

If you can find an old Heathkit HW32 (Monobander SSB series) and
rebuild it that might work better.

Allison


This might make a good contest: coming up with an SSB transceiver that
is capable of making real contacts on the air with a minimum number of
tubes. The IF and Xtal filter could be make bilateral for RX and TX, and
maybe using diode mixers (for the PD and TX mixer) might also allow
some bilateral shared stages in those areas as well. Even the TX predriver
could be switched for the RX RFA with some effort. I wonder how few
tubes it would take to make a 5-watt QRP xcvr for 20 meters? The
receiver doesn't have to be overly complex. A basic direct conversion
receiver could serve as the entire IF and detector, with the xtal filter in
front for single signal reception.

Pete k1zjh


Somebody already suggested the "Imp" that was in one of the later ARRL
SSB manuals (and the same author came up with a solid state version later),
and presumably had appeared in QST before that.

A different way of dual use, without the bilateral stages, is to have
a balanced mixer, the filter, IF strip, and then a balanced mixer. By
using broadband mixers, the first stage is either the receiver mixer,
or the balanced modulator for the transmitter. Then the balanced mixer
at the output of the IF stage is the product detector on receive, and
the conversion mixer on the transmit. The signals all go down the
strip in the same direction, and relatively little switching is needed.

One of those ARRL SSB manuals had such a transceiver, nice and small,
albeit with transistors.

Though, I seem to recall there was a transceiver made out of subminiature
tubes in the late fifties or early sixties. Unless I'm confusing it
with something else, it was in the Bill Orr Handbook.


Michael VE2BVW