julian814 wrote:
ken scharf wrote:
julian814 wrote:
Managed to find a regenerative receiver based on the 12AT7 tube. I've
been told I can substitute one of my 12AV6 tubes without a problem, so
that looks promising.

I have some twin triode tubes, as well. (6FQ7, 6BZ7 and 4BC8) I've been
wondering if I couldn't make some one tube receivers with them. (Use
one triode for regeneration, the other an amplifier.) As for the rest
of the tubes I have, I'd be willing to sell or swap for parts I'll
need.

Ralph

http://www.lindsaybks.com/bks/twin/index.html

I think this link might be more helpful and cheaper.

http://dzabcik.home.texas.net/doerle.html

Of course, it doesn't have Lindsay's notes on using newer tubes.


Ralph

Well If you are familiar with the book you know he showed a version
using a 6sl7gt tube. The 12at7 triode is identical to one half of the
6sl7 (except for heater voltage) so you can use a pair of these tubes in
the same circuit.

I built the #19 version, which worked ok but this tube is VERY
microphonic. I suspect the 12at7 will not have that problem.

Another interesting version of the theme was a single tube regen that
appeared in 'poptronics. It used a 6af11 compactron. This tube has two
triodes and a power pentode, so it will drive a speaker.

Also the current issue of QST shows a very simple untuned rf amplifier
that can be added to any tube type regen receiver. It uses only 7 parts
(a resister, 3 caps, 1 diode, an rf choke, and a transistor). The rf
choke and one of the caps can be eliminated if you directly couple the
output of the rf amp to the receiver via a link added to the input coil.
One of the caps and the diode are used to steal 9v dc from the 6.3v
heater supply. I would recommend adding this as it makes the receiver
easier to tune by isolating it from the antenna.