[Elecraft] Offset question

[Ron D'Eau Claire]

> Just so there is no confusion on this...  Zero Beat in Ron's context means
> the received signal should be exactly the same pitch (audio frequency) as
> the sidetone.
>
> Dave K9DC

Yes, that IS the definition of zero beat, at least as it has been used in
radio communications for the past 80 years or so.  However, there seems to
be a LOT of confusion about "matching pitches". There is NO need to be able
to tell if two tones are at the same pitch or to be able to hear pitch at
all in order to put two signals on exactly the same frequency.

Every so often someone comments that they have no sense of "pitch" so they
can't zero beat two signals. I've never been able to figure out what it is
that they are doing, but it is certanly NOT "zero beating" the signals.

The process of "zero beating" two signals is how we put them on the same
frequency without a clue about either the pitch (frequency) of the tones.
Zero beating is the process of having two tones audible at the same time,
and then adjusting their relative levels so a third tone can also be heard.
This tone is the hetrodyne or difference between the two tones. If the two
tones are 100 Hz apart, the third tone will be 100 Hz. It's necessary to
make the two tones near the same volume in order to hear the hetrodyne
clearly.

Once the hetrodyne is audible, ignore the other two tones and simply adjust
the frequency so the hetrodyne drops lower and lower in pitch. Finally, a
point will be reached where it can't be heard at all. Instead there will be
a rhythmic "beating" or "whosh,whosh,whosh" sound. Continue adjusting the
frequency until this "beating" sound drops to zero -and you have "zero
beat".

The biggest problem most people have in learning to do this simple task is
that they have one tone a lot louder than the other, so the louder tone
drowns out the hetrodyne.

I guess we've "beat that subject to death" which is something different from
"zero beating" as well, HI!

Ron AC7AC
K2 # 1289