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Old November 14th 04, 02:12 AM
John Steffes
 
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Some Regens are better than others. Some Regens are better than
Superhets. Example: the home-brew Regen we use for S.W. is a little more
sensitive an about as selective as our straight forward low-end
Hallicrafters S-38. The home-brew Regens' selectivity is improved by a
judicious r.f. coupling and a.f. extraction design not found in
conventional Regen design. On the other hand, you wouldn't want to call
on a Regen for serious communication work.

Bottom line: Regens are fun, simple, inexpensive, forgiving, and if
designed well, will compete with low end superhets. For serious radio
communication, the superhet can be designed to perform giddy acts from
beyond.

John
m II wrote:

Is the Superheterodyne set over rated? It seems to me there were certain
advantages to the OLD ways. Ease of control perhaps not being one of them.

What was the WORST feature of the Regenerative sets? The BEST feature?

Would it be worthwhile to build a kit?






mike


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Old November 14th 04, 03:15 AM
Michael Black
 
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matt weber ) writes:
On Sat, 13 Nov 2004 07:20:09 GMT, m II
wrote:


Is the Superheterodyne set over rated?

Useful Bandwidth control and true synchronous detection are things you
cannot do with a Regen. Try receiving SSB or FM with a Regenerative receiver.


You most definitely don't need a synchronous detector for SSB reception;
indeed there is nothing to synchronize to. One can argue that the "direct
conversion receiver", ie a mixer and oscillator that translates the signal
directly to audio, is just a variant on a regen set to oscillate in order to
likewise beat the signals down to audio. A regen does have its limits
when it comes to SSB, including the lack of selectivity and since they
were built for simplicity, lack of stability.

Synchronous detection is not need for FM, either. What may be fooling you is
that one way to detect FM is to use a phase locked loop that tracks the
incoming signal; the feedback voltage hence follows the modulation of the
signal and recovers the audio. There are plenty of other FM detectors, but
yes the regen isn't usually one of them. Theoretically it can be used
like any AM detector to demodulate FM by mistuning and "slope detection".


The BEST feature?

Simpllicity. You could build a fairly useable radio with just 3
stages, in fact quite a few 27 Mhz walkie talkies were built that way,
with the Regen detector doubling as the Oscillator/output stage in
transmit.


Actually, regens were rarely or never used for those applications. It was
the superregen, also patented by Howard Armstrong, that was used. It
was an extension of the regen, the addition being quenching of the detector
at frequency in the hundreds of kiloHertz range. This pulsing of th
regen detector allowed for maximum gain without the instability of the
regen going in and out of oscillation. It also results in a much wider
bandwidth. Note that the superregen is promoted for reception of FM, though
in its case it is slope detection.

Michael

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Old November 14th 04, 06:03 AM
Jon Lippert
 
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Some Regens are better than others. Some Regens are better than
Superhets. Example: the home-brew Regen we use for S.W. is a little more
sensitive an about as selective as our straight forward low-end
Hallicrafters S-38. The home-brew Regens' selectivity is improved by a
judicious r.f. coupling and a.f. extraction design not found in
conventional Regen design. On the other hand, you wouldn't want to call
on a Regen for serious communication work.

Bottom line: Regens are fun, simple, inexpensive, forgiving, and if
designed well, will compete with low end superhets


Greetings! I built the Ten Tec 1253, 9 band a few years ago. I thouroughly
enjoyed using it. Recently I lost the FETs due to leaving the radio hooked up
to the antenna during a freak thunderstorm. Arthritis will no longer allow me
to repair it so I am looking into crystal sets for shortwave. The 1253 took
patience in tuning, but the challenge made the listening more fun. Side band
was very difficult,but I did manage to copy even on 20 meters during the day.
Build one. It is worth the effort. Jon.
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Old November 14th 04, 07:15 AM
Frank Dresser
 
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"Michael Black" wrote in message
...

m II ) writes:


Is the Superheterodyne set over rated? It seems to me there were
certain advantages to the OLD ways. Ease of control perhaps not being
one of them.

What was the WORST feature of the Regenerative sets? The BEST feature?

Would it be worthwhile to build a kit?


You have to remember that Howard Armstrong, who "invented" the regen
(he was issued the patent, but it's something you really just trip over
rather than invent). then went on to invent the superheterodyne, which
does seem to have come from deliberate effort. He was disatisfied with

the
regen, which led him to experiment and explore until he came up with the
superhet.

The regen is simple, and that's a big advantage. It provided good gain
for a single stage, and it provides better selectivity than a single tuned
circuit without regeneration.

Beyond that, it's limited. It won't provide great selectivity, it is
finicky, and can receiver limited types of modulation.

No, it can't be a serious contender for the superhet.

On the other hand, there is certainly an appeal to building something, and
a regen does make it easier. One can even argue that if someone is going

to
build a simple receiver, a regen makes more sense; not only simpler, but
suffering from none of the superhet's disadvantages when done simply.

Some of the disadvantages, apart from the lack of good selectivbity, can
be overcome at the cost of more complexity. Add an an amplifier stage
before the detector, to isolate it from the effects of the antenna (which
can cause the regen to go in and out of regen when you don't want it), add
some voltage regulation, add an audio filter. Make sure theregen control

is
smooth.

Charles Kitchin has done a fair amount of work on regens in recent years.
Some of the circuits are floating around the web, and he's had quite a few
articles in QST. I'm too lazy to dig up the biography once again.

There have been a few other "improve the regen" articles in QST in the
past decade, though I can't remember dates or author. The first used an
optoisolator to add some isolation, and there was another using a bridge
for isolation.

Michael



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Old November 14th 04, 07:57 AM
Frank Dresser
 
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"Michael Black" wrote in message
...


You have to remember that Howard Armstrong, who "invented" the regen
(he was issued the patent, but it's something you really just trip over
rather than invent). then went on to invent the superheterodyne, which
does seem to have come from deliberate effort. He was disatisfied with

the
regen, which led him to experiment and explore until he came up with the
superhet.


[snip]

The local oscillator operates on the regenerative principle, so Armstrong
was obviously in a good position to develop the superhet. Fessenden had
discovered heterodyning years before, but he was using Poulsen arc
generators as oscillators.

Frank Dresser




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Old November 14th 04, 03:25 PM
Brian Hill
 
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"m II" wrote in message news:...
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Lines: 15
Message-ID: JAild.83554$E93.76920@clgrps12
Date: Sat, 13 Nov 2004 07:20:09 GMT
NNTP-Posting-Host: 142.59.63.227
X-Trace: clgrps12 1100330409 142.59.63.227 (Sat, 13 Nov 2004 00:20:09 MST)
NNTP-Posting-Date: Sat, 13 Nov 2004 00:20:09 MST
Xref: sn-us rec.radio.shortwave:437579


Is the Superheterodyne set over rated? It seems to me there were
certain advantages to the OLD ways. Ease of control perhaps not being
one of them.

What was the WORST feature of the Regenerative sets? The BEST feature?

Would it be worthwhile to build a kit?






mike


They take skill to use but a good regen is very sensitive. I've got a
homemade regen that's selectivity isn't bad either. I had a military RAL7
that was a good radio.


--
73 and good DXing.
Brian
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A lot of radios and 100' of rusty wire!
Zumbrota, Southern MN
Brian's Radio Universe
http://webpages.charter.net/brianhill/


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Old November 15th 04, 01:27 AM
John S.
 
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I think it would be fun to build one. It would also be fun to learn
to use one. But like tuning a superhet with bandspread dials and
preselector a regen gets old quickly because tuning around is so slow
and fiddly. They are great basis for comparison because they show how
far radio receivers have come.

m II wrote in message news:JAild.83554$E93.76920@clgrps12...
Is the Superheterodyne set over rated? It seems to me there were
certain advantages to the OLD ways. Ease of control perhaps not being
one of them.

What was the WORST feature of the Regenerative sets? The BEST feature?

Would it be worthwhile to build a kit?






mike

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Old November 15th 04, 06:34 PM
Stan Barr
 
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On Sun, 14 Nov 2004 23:02:15 -0700, matt weber wrote:
Regen can handle SSB, in practice it cannot due to lack of a stable
carrier, lack of a product detector, and inadquate sensitivity.


Of course a regen rx can handle SSB. My 3-tube set works fine on the 80m
and 40m ham bands. Naturally, the tuning needs an occasional tweak but
once it has warmed up it will stay on an ssb signal for quite some time.
Selectivity is not an issue - that is done at audio like a direct conversion
set. Tests by ZL2JJ have shown a good regen receiver to be as sensitive as
many modern superhets.

The German military were using regen receivers* right through WW2 for
AM and CW reception and if you can resolve CW you can handle SSB.

* For example the excellent Hagenuk Ha6K39b tranciever.
--
Cheers,
Stan Barr stanb .at. dial .dot. pipex .dot. com
(Remove any digits from the addresses when mailing me.)

The future was never like this!
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