In ,
(Richard Cranium) wrote:

Frank Gilliland wrote in message . ..
In , Earl Johnston
wrote:

On Wed, 09 Jul 2003 19:30:37 -0700, Frank Gilliland
wrote:

Lou Franklin can help! Pay him money and he will help you to violate federal
regulations! But don't ask him to help you pay the fines...LOL!

While he certainly can help you break a number of federal regulations,
he also offers some things which "appear" to provide a legal
performance boost.

I don't have the background or education to know if these things are
the CB equivalent of snake oil, or if they really work. I would
appreciate the comments of the many technically proficient members of
this newsgroup.

In particular, I'm looking at the plans for his CP beam antenna

Circular polarization of a signal is caused by "Faraday rotation" as a signal
passes through the upper atmosphere, and occurs mainly with frequencies from 100
to 1000 MHz. Unless you plan on tuning in on satellites in that frequency range,
an antenna designed for circular polarization isn't going to do much good. IOW,
the term was probably adopted into CB mythology to describe a helical antenna,
which is no more efficient than any fiberglass stick antenna, and less efficient
than an unloaded whip.

Nearly all CB radio antennas are vertical, and therefore vertically polarized.
You are wasting your resources trying to make an antenna that's capable of
receiving both vertical and horizontal polarization. For lots of antenna
information, here's a good place to start:

I'd like to be there when you tell that to Avanti, makers of the
PDL-II and Moonraker series of antennas, which feature selectable
horizontal and vertical polarization! I think they would laugh at you,
Frankie, as will the many owners of those antennas.

I would like you to be there, too. And who knows -- if you can keep your mouth
shut and your mind open you might actually learn something.

http://www.ac6v.com/antprojects.htm

and
the Digital Speech Processor kit. I have the skills required to
construct either, but not the knowledge to know if either project is
worth the effort.

A speech processor is an excellent idea, but I have no idea if Lou's even works.
I certainly have some misgivings about 90% average modulation!

What? A "commercial broadcast engineer" that can't look at a schematic
and know whether the circuit works as advertised or not?

Not when you have four high-gain, high input-Z OP-amps on the same chip, all
inverting, all DC isolated on both the inputs and outputs, and all outputs are
unloaded. IOW, any one of them could start oscillating at any time. Or, like I
said, the thing may not even work at all because it might lock up on power up.
As far as the "processing" is concerned, it's nothing more than a clipper. The
whole thing can be done much more easily with a few discretes, and I would
certainly have much more confidence in the circuit.

"90% average
modulation" would be great on AM (ask a real commercial radio
engineer, Frankie; they use 'em all the time),

Considering that the circuit is nothing more than a preamp and clipper, I have
no idea where he gets the idea that it will achieve 90% average modulation. And
in case you missed class, any form of compression and/or clipping is a form of
distortion; i.e, more compression equals more distortion. Years ago, some AM
broadcast stations would crank up the compression to the point where the sound
quality was offensive, but that's rarely done anymore.

but when the operator
isn't saying anything there'd be a rather obnoxious noise transmitted
as the circuit searches for anything to keep the modulation at 90%. As
witness the BBC some years ago, until they learned to turn down the
processing.

You are professing your ignorance yet again -- noise gates have been around
almost as long as compression. And for your information, compressors and gates
are considered ancient technology in broadcasting these days, because with the
newer digital audio processors you can tailor your response curve to just about
shape you want in less than a minute via software.

But why don't you know this IF you're really a commercial broadcast
engineer as you claimed?

*-plonk-*






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