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Old November 10th 05, 06:40 PM
 
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Default What is a heterodyne.....

Michael Black wrote:
A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.


Hams often describe their offspring as "harmonics". Some say that it
would be more appropirate to call them "heterodynes". If the children
were especailly wonderful, they would be "superheterodynes".

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Old November 10th 05, 07:01 PM
Caveat Lector
 
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Default What is a heterodyne.....


wrote in message
oups.com...
Michael Black wrote:
A heterodyne is when two frequencies are beat together, causing a third
frequency to be generated.


Hams often describe their offspring as "harmonics". Some say that it
would be more appropirate to call them "heterodynes". If the children
were especailly wonderful, they would be "superheterodynes".


Or spurious emissions huh
Just kiddin

--
CL -- I doubt, therefore I might be !


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Old November 10th 05, 07:15 PM
 
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Default What is a heterodyne.....

Many years ago,Superheterodyne Shortwave Radios were all the
rage,Shortwave Radios wise,that is.There were ads in magazines
gloryfying the advantages of Superheterodyne.Factory made and kits were
available,Superheterodyne Shortwave Radios.
Superheterodyne cuhulin

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Old November 10th 05, 07:35 PM
Michael Black
 
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Default What is a heterodyne.....


) writes:
Many years ago,Superheterodyne Shortwave Radios were all the
rage,Shortwave Radios wise,that is.There were ads in magazines
gloryfying the advantages of Superheterodyne.Factory made and kits were
available,Superheterodyne Shortwave Radios.
Superheterodyne cuhulin

Maybe the newsgroup would be better if you didn't spew nonsense.
If you know nothing of a topic, don't bother posting.

Virtually every shortwave receiver in production today, and for many a
decade, is superheterodyne. They all convert the incoming signal
down to a fixed frequency for selectivity and amplification.

The exceptions would be fairly obscure kits, using regeneration,
or maybe some commercial amateur radio receivers or transceivers,
using direct conversion (which heterodynes, the incoming signal
directly down to audio).

You'd have to go back many decades before you hit a point where
a large percentage of shortwave receivers were regenerative. Go
back forty, and some would be regenerative, albeit they'd be at
the low cost end of the spectrum. Go back to the thirties, and
regeneration likely was still common, because superheterodyne designs
used more components and hence were too costly for many in the depression
era. Go back to the twenties, and besides cost there were still bugs
(the issue of images for instance), and maybe even a reluctance to move
to something new.

Once again, Howard Armstrong received the patent for the regenerative
receiver in 1914, US patent number 1,113,149,

He received the patent for the superheterodyne receiver in 1920, US
patent number 1,342,885.

And he received the patent for the superregenerative receiver in 1922,
US patent number 1,424,065.

Howard Armstrong took care of all basic receiver design beyond the
simple "crystal radio" and the TRF (Tuned Radio Frequency) receivers.
And took care of that by 1922.

Everything that came later were variants of those three (or more
like two, regen and superhet) basic concepts, incremental improvements
but no fourth type of receiver.

Michael

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Old November 10th 05, 08:08 PM
bpnjensen
 
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Default What is a heterodyne.....

Michael - thanks for these excellent and tidy thumbnail explanations
and histories. I guess I've long *sort of* known about these things,
but your concise posts encapsulate them beautifully and make them very
concrete.

Bruce Jensen



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Old November 10th 05, 08:16 PM
 
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Default What is a heterodyne.....

Maybe so,but I have an Allied Radio catalog here,the 1941 Spring Summer
issue of the catalog and many of the radio ads in the catalog (which I
am looking at right now) do say things about Superhet (Superheterodyne)
and S-P-R-E-A-D band tuning and Regen and super Magna Beam antennas.
cuhulin

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Old November 11th 05, 07:30 AM
Cmdr Buzz Corey
 
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Default What is a heterodyne.....

Michael Black wrote:

You'd have to go back many decades before you hit a point where
a large percentage of shortwave receivers were regenerative. Go
back forty, and some would be regenerative, albeit they'd be at
the low cost end of the spectrum. Go back to the thirties, and
regeneration likely was still common, because superheterodyne designs
used more components and hence were too costly for many in the depression
era.


Nope, nearly all radios by the early 1930's were superhet.
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