Don Bowey wrote:
I have posted the schematic and parts list of a 50s regenerative receiver
(224 K) on a.b.s.e., which I received from Colin, K7fm, This receiver has
been discussed on boatanchors.

It is part of a construction article, now a 4.7M pdf file, which I will post
if there is any interest for it. The project receiver is fairly typical of
what someone in the 50s might build as a shortwave listening receiver, or
for a beginning ham radio receiver.

To pique your interest, the detector uses what is a modified Hartley circuit
using an unusual selection of tube.

In the .pdf file, there is a 5Y3 tube power supply schematic, of 50s
overkill design.

Don

While ANY 4 or 5 element tube will work as a regen detector, in the electron
coupled feeback circuit (long name for Hartley) the suppresser grid (if present)
should NOT be connected to the cathode, but directly grounded. So on this
basis the 6AQ5 isn't the best choice. Below 15mhz control of regeneration won't
be a problem, but above that the tube choice might make a difference.
The fact that the 6AQ5 is a power tube doesn't matter, in fact I have seen
807's used as regenerative detectors!

If you can't connect the suppressor element directly to ground, the plate tickler
feedback circuit is better than the hartley. Also instead of a tap on the main
coil, a tickler can be placed in the cathode circuit. This makes it easier to adjust
the number of feedback turns. In either case cathode feedback saves a pin on the
plug in coils.