Paul, though technically correct, in reality I have never heard anyone say
"let's QSY up 5 KC per second."
They would say up 5 KCs.
Though adding the term "per second" is totally correct, it was also totally
useless in those cases.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Paul
Littleton
Sent: Saturday, March 28, 2015 5:25 PM
To: tentec@contesting.com
Subject: [TenTec] My Two Cents - Units
I was trained as a mechanical engineer in the late '70's. At that time the
United States was supposed to convert to SI as a system of units. Just
before my senior year, my schooled realized that the U.S. wasn't going to
convert after all and I spent a fair amount of effort learning the existing
system of units. As a result I was forced to deal with both systems.
Most people, in this country, learn to loath the "metric" system because
they are taught conversion factors between "English" and "metric" systems
until they go insane. If so,done is immersed in SI, it is really a rather
nice system to deal with.
I make a point to separate "metric" from SI, because there are a number of
metric systems and one SI system. Hertz is in SI and cycles/second exists in
the other metric systems, as well as the English system. Hertz is just a
name given to cycles/second to honor a German physicist In the SI system of
measurement. No big deal, just a name. There is really no conversion
involved. One Hertz equals one cycle/second.
I think the problem that may have started this discussion is the prefix used
to move the decimal point around. An interesting note is that the same set
of prefixes is used for both SI and the English systems. One kilohertz
equals one kilocycle/second. One megahertz equal one megacycle/second.
Another possible point of conversion is what I call the "lazy" use of
units. Frequency cannot be specified in cycles or kilocycles. The time unit
needs to be included.
Best Regards,
Paul
tapped out on an iPad
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