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November 13th 04, 06:35 PM

Edwin, not Howard.

On 13 Nov 2004 17:48:14 GMT, (Michael Black)
wrote:

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