On Apr 21, 5:34�am, Tim Shoppa wrote:
On Apr 21, 1:05�am, "Phil Allison" wrote:

"AF6AY"

Everyone ought to realize that "Wikipedia" data can be written by
ANYONE

** As are NG posts.

The difference being that Wikis are full of checkable references and are
subject to on-going correction.

The best Wikipedia articles are often filled with good checkable
references, but other times it sounds like they were written in a
foreign language and translated into English and have few (if any)
good references.

One can write just about anything so that it looks good and
authentic. :-)

There is plenty of rather authentic information on Edward Howard
Armstrong, including scans of Armstrong's patents.

As to the words "supersonic" and "subsonic" I doubt that those were
coined
prior to around 1930, rather long after the superheterodyne came into
being as the very model of a modern major receiver structure.

Argument over the 'super' prefix/designator would come a cropper on
things
like the super-regenerative receiver which use a sort of burst
oscillation at
frequencies quite higher than young adult hearing maximum of 15 KHz,
i.e., "supersonic" in terms of frequency. In aerospace, "supersonic"
is a term for going faster than the speed of sound.

As to "typically converting the signal frequency below the range of
tuning," that WAS true but it applies only to most superhets that were
designed prior to WWII (at least 60 years ago). Those mixers used
only the difference frequency output while the sum frequency output
just dissipated internally. That changed with UP-conversion, notably
in Collins Radio designs for their lowest selectable bands, then in
the first wideband spectrum analyzers covering a full GHz in one
sweep. Those early spectrum analyzers would up-convert 0 to 1 GHz to
a 2 GHz first IF, then down-convert from there. 2 GHz is so far above
'supersonic' that it would be a misuse of it.

Somewhere there's a bunch of people who spend their time correcting
and improving Wikipedia entries, and I think overall they are doing a
good job, but that doesn't mean the result is always devoted to my
interests. Just like anything else in this world, it's got workers and
it's got managers and they aren't always devoting their attention to
the little corners of arcania that I live in.

There's also a lot more folks who just vent their frustrations on
everyone else, such as Phil Allison (who's profile can't be accessed
because he violated the Terms of Service on Google).

As to the ORIGIN of technical terms, speaking as a lifetime engineer
and technician and worker IN engineering, it matters little as to
etymology but a great deal more on the SUBJECT the word is referring
to.

If anyone wants to think "supersonic" applied in 1918 to anything at
all, then they are welcome to point out the "supersonic" aircraft of
that time...made of pieces of steel, wood, wire, and fabric. :-) It
was a long time between 1918 and 1947 when the first aircraft broke
the 'sound barrier' (Bell X-1 piloted by Chuck Yeager).

73, Len AF6AY