Evolution of the
On October 8, 2014
a guy named Greg emailed me out of the blue. He included seven
attachments in the email. Some of them were plans for a regen
from a Lindsay publication. He wrote "Enjoy, let me know how it works
out for you."
I didn't get around to playing with the circuit till the middle of
The schematic Greg sent me.
I altered it to
receive the AM broadcast band.
The article said to use a toroid coil form
but I didn't have any. I tried two straight ferrite rod type coils but
they didn't regenerate well.
I used a plug-in coil made by Elmer Osterhoudt.
were pretty amazing considering there was only one
I decided to use the same type coil that is used in
This picture started a thread on
Antenna tuner coil on the left.
It would eventually be discarded. The main coil is on the
right. The red winding is for the RF amp but
it was also discarded. The top winding on the right hand is the
"tickler" coil which was eventually
The first version of the radio. The Peebles antenna
tuner and an external amplifier were used, and I tuned to a corny old
song for the movie. There is no RF amp.
The problem with the above setup is that you can't get your hands near it or
it throws off the regeneration. Or looking at it another way, once you
tune in a station, don't take your hands off the knobs!
The next idea was to use the Lindsay "Twinplex" circuit to build a solid
state version of the Peebles Two-Tuber, with the antenna tuner and
amplifier on a single chassis.
...Therefore the front panel was
made of cardboard with aluminum tape as a shield.
It was time to make a setup that would be
easier to work with, but semi-permanent so it could be changed.
In these pictures the audio amplifier has already
been built. I ran into trouble with
this very board while building the
and this working unit was
left over from that project.