Regenerative Receiver?
Lars Brandt
You can build a receiver with only 1 transistor and you have a sensitivity
of a few uV.
To tune the receiver you have 2 turnbuttons, 1 for tuning and another for
regeneration (how many times the signal shall pass through the transistor).
It's uncomfortable to tune but I think they can pick down signals as a good
communication receiver?
Or you can only hear the greatist international broadcasts.
Is there anybody who know a kit to build a such receiver and where I can
find it?
Regards
Lars
Mike Bleiweiss
20, 25, 22, 19, 17, 16, 15 and 13 Meter bands. Lets you listen to AM, SSB,
CW, WWV, RTTY and packet.
Goes for $59 I think.
Fairly simple to build. It's not a $1500.00 receiver, but it picks up the
stronger foreign stations.
Mike
Tony Skitt
I built one when I was in the school Radio Club - I was 13 I think, so it
was a long, long time ago. It used a single OC-45 transistor, and I managed
to receive quite a few French and German SW stations with it, from the UK.
But if you are thinking of building one as a substitute for a superhet
receiver, especially a modern portable (e.g. Sony ICF 7600G), forget it.
Sensitivity, selectivity and stability are all mediocre, and you are never
quite sure of the frequency you are tuned to.
Regards
Tony Skitt
Lars Brandt wrote in message <_7nA6.3951$sk3.1...@newsb.telia.net>...
Jake Brodsky
wrote:
If sensitivity were the only issue here, a regenerative receiver would
be all we'd need. But it's not.
The problem on SW is that you often get weak signals buried in a mess
of much stronger signals. Were that weak signal the only one around,
you'd be able to detect it very nicely with a well designed
regenerative receiver. The signals nearby, however, are likely to
generate interference known as IMD (which stands for Inter-Modulation
Distortion).
The more regenerative gain you create, the more IMD you'll hear. So,
given a quiet band, you may actually be able to comfortably detect
signals only of only a few micro-volts at 50 ohms. The same signal,
however, in the typical crowded broadcast bands of today would go
un-noticed for all the background distortion present.
Another downside to regenerative receivers: they radiate. By that, I
mean that you'll need to isolate your detector with a front end
amplifier so that your detector doesn't trash the spectrum for others.
Now it's no longer as simple a project.
However, I've seen an article in QST a couple years ago about an
Optically Coupled Regenerative (OCR) receiver. If you're really eager
to see what a regenerative receiver can do, this wouldn't be a bad
project to start with...
73,
Jake Brodsky, AB3A mailto:fru...@erols.com
"Beware of the massive impossible!"
Bill Meacham
>
> On Mon, 09 Apr 2001 18:24:58 GMT, "Lars Brandt" <lov.b...@telia.com>
> wrote:
>
> >Is there anybody who have expericence of regenerative shortwave receiver.
> Another downside to regenerative receivers: they radiate. By that, I
> mean that you'll need to isolate your detector with a front end
> amplifier so that your detector doesn't trash the spectrum for others.
> Now it's no longer as simple a project.
>
> However, I've seen an article in QST a couple years ago about an
> Optically Coupled Regenerative (OCR) receiver. If you're really eager
> to see what a regenerative receiver can do, this wouldn't be a bad
> project to start with...
>
> 73,
>
> Jake Brodsky, AB3A
Ten Tec has two kits...I hear one is very nice, the other one is
so-so. I was wanting to compare my results from building an old
antique style Doerle 2 tube set with something more modern...a
friend lent me his MFJ-8100K and I am absolutely amazed with it.
Its a fairly simple kit, a non-radiator, and stable as a rock.
There's no comparison to the old style tube regens or the corny
little solid-state things you hack together out of an old
magazine. Many inexpensive (and not so-inexpensive) solid-state
receivers overload in my location close to a 5kw AM) but this one
does not. MFJ has done a good job of making this seem like a
'real' receiver.
---
Bill Meacham
Vieques, PR
Brenda Ann
remember now I had one when I was 15. I lived on the Oregon coast, and my
superregen would pick up weak Portland stations that my 5 tube superhet
couldn't even begin to hear. But you're right about the selectivity.. they
really don't have any. :)
Thanks for jogging my memory of a fun time in my life. :)
Chuck Carroll
MFJ Enterprises, www.mfjenterprises.com, has a Regenerative receiver kit for
$69.95. Four knobs, two earphone jacks, uses a 9 VDC battery. I don't have
experience with it, but I'll guess that it is of better quality than Radio
Shack.
Chuck
Ross Archer
Brenda Ann wrote:
> I had so completely forgotten about superregenerative recievers.. :) I
> remember now I had one when I was 15. I lived on the Oregon coast, and my
> superregen would pick up weak Portland stations that my 5 tube superhet
> couldn't even begin to hear. But you're right about the selectivity.. they
> really don't have any. :)
Regens and supergennys are actually quite different in selectivity.
I don't pretend to understand the math, but the "Q" of the tuned input
circuit increases as you get closer and closer to oscillation, such that
selectivity increases. In fact, I once saw an article on how to make
your IF stage more selective by providing some regenerative feedback.
I think super-regens are very broad because they spend so much of
their time far from that critical tipping point of oscillation where the
selectivity is actually decent, and a lot of time in actual oscillation or
far away from oscillation.
Just what I've read.
Michael Black
Your message gives the impression that you are in Europe, so this
information may not be as handy to get ahold of as for those of us
in North America.
Charles Kitchin has written quite a bit about regenerative receivers
in the past decade. He's gone back and looked at the early material
on the subject, and created some interesting designs using semiconductors.
All of them use very common and inexpensive components.
(He's done similar work with superregen receivers, and claims to have
improved their problem of wide bandwidth).
There is some overlap in his articles, because some have been
to explore the art, and others have been specifically
construction articles which expand on the circuits shown in
the first type of article.
I've gotten email from him a number of times, because he's
seen posts of mine that point to his articles (he doesn't
have newsgroup posting access). In one of them, he included
a listing of his articles, which is down at the bottom of this post..
It's incomplete, because he had an article in Radio Electronics around
1993 that described the operation of the regen and showed some circuits
(and I can't find that article). And one of his simple regen
receivers was in the ARRL Handbook for an edition or two.
One might check the library to see if they have a recent
ARRL Handbook that might include the article. Back issues
or copies of the articles, should be available from the ARRL,
http://www.arrl.org Local amateur radio clubs might also
be a place to find such material.
Charles Kitchen has also mentioned a website with an article
of his about making a simple regen receiver. I've never looked
at the schematic, but it may be similar to one of the circuits
published in the traditional medium:
http://www.chelmsford.com/bars/regenproj.htm
He also mentions that these two sites have regen receivers
based on his circuits:
http://home.swbell.net/aa5tb/regen.html
http://www.swlink.net/~w5jh/index.htm
The advantage of a regen is that it is simple, and even if
the performance won't be so useful at this point in time,
one can learn quite a bit by building one. Others have commented
on the radiation issue; one thing about transistors is that they
will generate a much weaker signal than when a tube was used,
and they also make it easier to put a stage of isolation between
the antenna and the detector.
One scheme that you once saw quite a bit was to go with a more
complicated design. By adding a mixer and oscillator stage ahead
of the regen detector, you'd get a superheterodyne receiver with
a regen detector; such a combination was once called a "supergainer".
Interestingly, the Sept 2000 issue of QST, along with the Charles
Kitchin article, also has a constuction article for such a receiver.
And that one points to the optically coupled regen that someone
else mentioned; it's in the June 1998 issue of QST.
I'd actually go with one of Charles Kitchin's simpler circuits.
It would be cheaper than a kit. Except for a germanium diode
(which once were common), the parts are easy to get, and you
can get away with subsituting what you do have on hand.
Michael
-------------------------------------------------------
Kitchin, Charles. "A Simple Regen Radio For Beginners", QST
magazine, Sept 2000, pp 61-64.
Kitchin, Charles. "High Performance Regenerative Receiver Design",
QEX magazine, Nov/Dec 1998, pp 24-36.
Kitchin, Charles. "An Ultra Simple W1AW Receiver", QST magazine.
May 1997, pp 34-35.
Kitchin, Charles. "Regenerative Receivers: Past And Present",
Communications Quarterly. Fall 1995, pp 7-26.
(Missing from this list is another one in QST, where he shows
a crystal controlled regen receiver, intended for receiving code
practice. I can't find the article at the moment. One of these
days, I'll have the articles and the germanium diodes "found"
at the same time, and build one of these receivers.)
Bill Meacham
> On Mon, 9 Apr 2001, Lars Brandt wrote:
>
> > Is there anybody who have expericence of regenerative shortwave receiver.
For the real homebrewer...
http://www.ezlink.com/~crash/parks/1distget.html
-BM
Tom2000
On Tue, 10 Apr 2001 03:14:09 -0400, Bill Meacham
<NOSPA...@coqui.net> wrote:
>
>For the real homebrewer...
>
>http://www.ezlink.com/~crash/parks/1distget.html
>
>-BM
Thanks very much for the link. Takes me back to the old days when I'd
find old QSTs and Radio Amateur Handbooks from the 30s and 40s and
pore over each project in wonder. This one takes "simple" to a new
level, though!
73,
Tom
Stan Barr
You can certainly hear a lot more than strong international broadcasts, I
used to do some serious DXing with a regen. and my 2 valve (tube) receiver
I have now works just great - especially on the ham bands.
The GQRP club has published a number of designs for solid-state ones over
the years.
Try: http://www.kanga.demon.co.uk they do a kit for one.
--
Cheers,
Stan Barr st...@dial.pipex.com
The future was never like this!
Stan Barr
Yep, they're different animals. My regen rx has enough selectivity, when
carefully adjusted, to start rolling off the high audio frequencies on a
SW AM broadcast station. Say about 7 or 8KHz bandwidth, shape factor not
so good though.