Banishing the birdies and beasties

[Glen Zook]

In the February 1961 issue of QST there is a
Hallicrafters advertisement on "how to banish the
birdies and beasties" on phone operation.  Basically,
it was their way of avoiding QRM in the phone bands.
Although a full page in their explanation of what to
do, it basically came down to everyone exactly (well
as close as possible) zero-beating frequencies that
follow a specific pattern.  What they proposed was use
of frequencies ending in the following KHz:

03, 07, 11 ,15, 19, 23, 27, 31, 35, 39, 43, 47, 51,
55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, and 99.

That is, for example, one QSO on 3803 KHz, the next
one on 3807 KHz, then 3811, etc.  By doing this, there
would be no measurable interference from the adjacent
"channel" and since the frequencies would be "zero
beat", there would be much reduced interference from
someone a "ways" away who were operating on the same
exact "channel".

This sequence was proposed by Bil Harrison, W2AVA
(only one "l" in his name) as "guest editor" for
Hallicrafters in that particular advertisement.  By
the way, this was #73 of the series of advertisements.
 This series had various "tips" on operating,
improving performance of equipment, etc.

I had not paid any attention to this concept before.
But, it does make technical "sense".  It was pointed
out in the ad that if only 20% of the amateurs used
this plan that there would still be a substantial
reduction in QRM.

Anyway, it is food for thought (although I seriously
doubt that anywhere near 20% of those operating would
even consider the plan).  The things one finds when
one goes "thumbing" through a stack of "old"
magazines.

Glen, K9STH

=====
Glen, K9STH

Web sites

http://home.attbi.com/~k9sth
http://home.attbi.com/~zcomco

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