If Superheterodyne, why not Subheterodyne?
On Apr 20, 9:50*am, Tim Shoppa wrote:
A terminology question I suppose about the derivation of the term
"Superheterodyne" more than anything else:
Does the "Super" actually mean anything? Is there a Subheterodyne?
Traditionally superhets mix a higher radio frequency down to a lower
IF frequency, but certainly in the past few decades radios with IF's
above the RF frequency have become very common in broadband
applications, and those are still called superhets, not subhets :-).
Google turns up a couple hits on subheterodyne but other than one that
might mean "IF higher in frequency than RF" I don't recognize what
they mean..
I suspect that "Super" was more a marketing term than anything
else :-).
Tim N3QE
I thought it was a contraction of "supersonic heterodyne".
At that time receivers were TRF and in many cases used reaction (i.e.
controlled positive feedback) to improve selectivity and gain. This
could be exploited to receive CW signals by advancing to the point of
feedback resulting in an audible heterodyne (whistle) at the output
whwn tuned close to a signal.
The supersonic heterodyne performed in a similar way but was
intentionally above audible range (i.e. supersonic) for amplification
at the intermediate frequency.
kevin
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