From: Paul Harden (firstname.lastname@example.org)
I have not seen the Rx article by Orr in CQ so don't know what its
based on. But a couple of months ago I built a 3 transistor regen
receiver by Charles Kitchin, Analog Devices, and published in the
AUGUST 18, 1994 issue of Electronic Design News (EDN) p. 98-99. I
think this is the article/schematic Dave NF0R is refering to.
It is a neat circuit; the article is entitled "$10 receiver has
microvolt sensitivity." I wound the coil on an empty IC shipping tube
using (I think) about 4-5 times the windings shown in the article.
Eventually I bypassed the last audio transistor and dropped in an
LM386 for better audio. As is, the audio is a bit anemic and rebiasing
for higher gain made it oscillate. I changed the L-C for better
coverage of 40M. With a little practice, you can get CW on 7040
to sound pretty good. I was gonna write it up for CQC or anyone else
with interest, but got sidetracked with field day, etc.
If there is any interest in a really neat 3 transistor receiver, I'll
draw it up and make it available. Its an ideal project to build
something truly from scratch, if you've never done that before. A
piece of copper clad or perf board 3x3 inches will do it. (Not
counting homemade coil and cap). In the original article, the coil is
wound on an empty 35mm film canister, 12 turns total. Now that beats
a toroid any old day!
* * (dit dit with fuzzy logic)
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