On 3/30/2023 11:27 AM, Fred Atkinson wrote:
While I was working as a radio technician for Duke Power Company in
North Carolina] it used to amaze me as to the massive amounts of misinformation that CB users were spreading around. Mostly, it was
about radio theory. I will share three of the many stories I heard.
We had stopped for lunch at a truck stop one day. One of my
colleagues found somebody installing a power mike on his mobile CB
unit. When he asked the fellow why he was doing that, he said that
by putting more audio into the radio, he would get more power out of
it.
When my colleague explained to him that this was not true, the guy
replied, "Oh, no. All of the CBers are doing it. And they are
getting a lot more power out.". So, my colleague gave up on trying
to explain it to the guy. He was clearly hopeless.
Well, it's "sort of" true, at least in theory: the Class=D Citizens
Radio Service, which we know as "Citizens Band," uses Amplitude
Modulation, just like broadcast AM stations in the 550-1700 KHz
Broadcast band.
In order to perform Amplitude Modulation (AM), the transmitter must
add and subtract power from the outgoing carrier signal, and that
change is done by the transmitter's modulator, which takes the
microphone's signal and amplifies it to change the amount of
radio-frequency power going to the antenna.
However, in most CB sets, the amplified signals from the microphones
are run through a low-cost "compression" circuit called a "Clipper,"
which is supposed to maximize power output from the radio, but also
adds a LOT of distortion, and putting more audio power into the
clipper circuit just produces more distortion in the transmitted
signal. The increased power from a power mic, sad to say, is usually
heard as a distorted and hard-to-understand sound when it's received.
... which means, as a practical matter, that "Power" microphones only
increase the ability of salesmen to brag about their paychecks at
"Power" lunches.
We ran into one fellow who had actually installed the truckers'
antennas on a Volkswagen Fastback. There was absolutely no way this
was going to work as those two antennas have to be spaced wide enough
apart to work properly. He told me that the truckers antennas
'prevented messing up your SWR (standing wave ratio) when you have a
'huge metallic load' behind you'. Another hopeless radio expert.
Well, he might not have been aware of it, but that CB'er could have
achieved much better results by spending the time to properly bond a
single antenna's feedline to the roof of his car, which would provide
a proper "Counterpoise," and dramatically increase the "Field Strengh"
of the transmitted signal, and also maximize the strength of signals
received from other CB sets.
There was no point in sharing your expertise with them. They would
always believe other CB users before they would believe experienced
and well trained FCC-licensed radio technicians.
[Snip]
And there are many other true stories like these. I just couldn't
believe the massive amounts of misinformation they were spreading.
So many of them appointed themselves radio experts.
It wasn't long after I worked as a radio technician that I totally
gave up on trying to correct their misinformation. It was a lost
cause.
I've commented before on the sad tragedy which is the Citizens Band,
so I won't labor the point, other than to say "You're right."
Bill Horne
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