"Michael Black" wrote in message
ample.net...
On Sat, 21 Jan 2012, wrote:

On Dec 24 2011, 7:26 pm, Lemon Tree wrote:
I have written a short book on regenerative receiver that I have
available hehttp://www.vendio.com/stores/newproducts
and
hehttp://www.webstore.com/Regenerative...k,name,1372041...

I also have some negative resistance circuits and other things
hehttp://code.google.com/p/lemontree/downloads/list

Why not build some superhets instead? They work better.

Regens have crappy audio, making them undesireable for SWLing or
listening to the few hams worth listening to who are on AM...

Because they are simple, and it's good to get something to work early on.

But I certainly had meant to ask why should anyone buy his book. Charles
Kitchin over the past 20 years or so has done quite a bit with regen and
superregen receivers. He had long articles on both in Communications
Quarterly, looking back to the beginning (when most people have adapted
more recent work, so it's like a broken telephone). By going back to the
beginning, he was able to introduce some new concepts in superregen, which
would never come up based on most of the descriptions of the receiver.

Circa 1915, whenever Armstrong cameup with the regen, those things were
pretty simple, for the simple reason that tubes were expensive, and bulky.
In the transistor age, you can buy quite a few transistors for the price
of a tube in the old days. Make the regen solid, like a VFO (which it
really is). Add a buffer ahead of it, so the antenna doesn't affect
operation as much. Use a separate detector, something so lost in it all
that we talk about "regenerative detector" but the actual detection is
secondary to the regeneration. Add a voltage regulator, nobody would do
that in the old days, now it's hardly worth not doing.

That's some of the work Charles Kitchin has done with regens in recent
years, some very basic receivers for the beginner (including one that used
a crystal as the frequency determining element), some more complicated
than others.

Or go take his work and go back to the thirties, and build a supergainer
out of Frank C. Jones' Radio Handbook. A compromise/hybrid, it's a regen
with a converter ahead of it, or looked at another way, a superheterodyne
with a regen detector. Takes out some of the issues of the regen, it
isolates the detector from the antenna, the regen stage doesn't have to
cover a wide range (and if the converter is tuneable, the regen stage
stays on one frequency). You can even put a crystal filter between the
mixer and the regen stage.

So a regen still has potential. A simple receiver to accomplish building
something (41 years ago, I rushed down to the parts store with a list of
parts out of a magazine, and that project, and the one after, never
worked, in retrospect I can see lots of reasons why. But I kept at it,
and then I did get some things going, ironically out of scrap parts,
having learned enough to actually know what I was doing). But it can also
be a method of experimentation. Not to create Something Important, but by
trying new things, one can learn.

Michael VE2BVW

Ah, yes, the one tube (01A) regen on the broadcast band, late at night
North of Seattle Washington, listening to Snake Oil Salesmen from Del Rio,
Texas, With transmitters in Warez, Mexico........XERF, ISTR. A thrill that
must be experienced to be believed. And the Grand Old Oprey or the Barn
Dance!! KGO and KSL came in like gangbusters!!

Old Chief Lynn, W7LTQ