On Sun, 02 Sep 2007 05:22:25 -0700, Telstar Electronics
wrote:

|Why Do You Need a Speech Processor for Your CB Radio?
|Two-way radio communication relies on the modulation contained within
|the signal. Maintaining a high modulation level is crucial in
|providing the highest possible efficiency from any transmitter
|operating on AM, FM, or SSB modes. Two-way radios also rely on
|microphones that inherently change audio levels delivered to the
|transmitter. This causes transmitter modulation to fluctuate greatly
|depending on voice level and pitch. The average modulation of a
|typical voice signal is only about 40%. This low percentage applied to
|the transmitter, results in less than optimal transmission range.
|-------------

rubbish.

james

On Sun, 2 Sep 2007 05:25:43 +0100, " Peter"
wrote:

|Do you really have the spare time to explain everything
|to him? If so, do you really want to be faced with legal
|action when his brain implodes?
|----------

Not really.

james

On Sun, 2 Sep 2007 05:25:36 +0100, " Peter"
wrote:

|Amplitude Modulation... The output level "swings" above
|and below the carrier level.
|
|Get it yet?
|
|If the output level does not swing, then you have a constant
|amplitude... no amplitude modulation.
|No amplitude modulation = no audio. Unless, of course,
|you are using FM.
|----------------

Wrong

Unless you are using a peak reading wattmeter the power remians
constant with modulation in a DSB-AM Large Carrier signal. IF you were
to do a Fourier Transform of the AM signal under modulatioin you will
see a carrier frequency, the upper sideband frequencies, and the lower
sideband frequencies. The power in the upper and lower sidebands vary
with the power of the modulating signal. With an averaging wattmeter
you should see little or no movement of the power.

james

On Sep 2, 11:02 pm, james wrote:
On Sun, 02 Sep 2007 05:22:25 -0700, Telstar Electronics

wrote:

|VoiceMax is Different...
|VoiceMax uses a sophisticated AGC (Automatic Gain Control) circuit
|that installs inside your transceiver to hold the audio level
|constant, with less than 1% harmonic distortion. No "clipping" type
|processor can come close to this low distortion level. Whether you're
|whispering or shouting, VoiceMax holds your transceiver at 100%
|modulation allowing you to punch through heavy channel traffic without
|sacrificing voice clarity. VoiceMax incorporates a feature not offered
|on other processors. The adjustable noise gate allows the user to
|block unwanted ambient background sounds. This feature is especially
|helpful in mobile environments where wind and road noise can be an
|issue. VoiceMax works with your non-amplified dynamic microphone to
|give you tremendous audio punch without all the background noise
|associated with power microphones.
|-------------

With all that, the dang thing is nothng more than a fancy speech
compressor. I don't care how much fluff you want to put around it. It
is still a speech compressor.

james

Bottom line... it works as advertised. The ebay feedback supports
that...
http://feedback.ebay.com/ws/eBayISAP...edbackAsSeller
Whether you believe it or not is of little consequence...
www.telstar-electronics.com

"Telstar Electronics" wrote...
I suggest you review
http://en.wikipedia.org/wiki/Frequen...dulation_index
for details.

And I suggest that you learn the theory, rather than relying
on Wikipedia to try outwitting techs.
Some important things to note...
1. Wikipedia is only as accurate and complete as the
information put in by the public.
2. Wikipedia is no substitute for proper training.
3. One line or paragraph does not explain everything.
4. The real clue may be in the text - "approximately".

Your linked reference suggests that when the modulation
index is below 1, the bandwidth is approximately twice the
modulating frequency.
Bandwidth = 2Fm

If you are relying on such a simple, crude and innacurate
approximation, it only serves to show that you have neither
true technical knowledge or experience of FM CB.

If only you had read a little further, you would have
spotted another approximation that appears to dispute
the above method:
Bandwidth = 2 (Fd + Fm)

Note that the first approximation method does not include
deviation, and does not appear to define bandwidth.
As the sidebands are infinite, using the term bandwidth
without defining a level is like using dB without a reference
or level.
The second method includes both deviation and modulating
freqency, and does define bandwidth within the text.

But those are only approximations, a better idea of bandwidth
may be obtained from real figures...

With the CB audio bandwidth, the second sideband spreads to
over half way to the next channel, while the third sideband
spreads out to just below the adjacent channel carrier frequency.
A receiver cannot block these without blocking the wanted signal.
So while we can ignore the first sideband, anything above that
should be kept to insignificant levels.

At a modulation index of 1:
Second sideband = 11.5%
Third sideband = 2%
At a modulation index of 0.8:
Second sideband = 7.6%
Third sideband = 1%

These are NOT insignificant levels. Here in the UK, because
of legal restrictions of the day, many people once run on
just 10% (400mW) total power - and got decent distances
on it.


Bottom line...

Bottom line is that you are only interested in sales, and
you will say whatever it takes to get those sales.

Some of us, who have had FM CB from the beginning
in 1981, have already seen the sales tactics used. The
deception, selective facts, bending of reality and
outright lies used to make a sale.


Regards,
Peter.

"james" wrote...
" Peter" wrote:

|Amplitude Modulation... The output level "swings" above
|and below the carrier level.
|
|Get it yet?
|
|If the output level does not swing, then you have a constant
|amplitude... no amplitude modulation.
|No amplitude modulation = no audio. Unless, of course,
|you are using FM.
|----------------

Wrong

Once again you appear to have misread my statement,
making it appear that we disagree.

Before going on, read the quote (above) and note that:
I said output... NOT carrier.
I did NOT say that average power changes.

Unless you are using a peak reading wattmeter the power
remians constant

The power is not affected by the type of meter, all that
changes is the type reading that you take.

with modulation in a DSB-AM Large Carrier signal. IF you were
to do a Fourier Transform of the AM signal under modulatioin
you will see a carrier frequency, the upper sideband frequencies,
and the lower sideband frequencies.

There is no dispute that extra power is now in the sidebands,
but the output is varying over time, as an oscilloscope would
show.
The total power is varying with the modulating signal but,
as it should be swinging about the carrier level, the
average should be constant.

Surely we agree: the peak output (not carrier or average)
is varying over time, while the average power is constant.
At least is should be, if all is well and nobody has been
fekkin about inside the radio.

With an averaging wattmeter you should see little
or no movement of the power.

Of course not, the meter is intentionally ignoring them.
By averaging the reading, you are removing the short term
variations... but that does not mean they are not there.

Just like a business looking at average sales - the seasonal
fluctuations are ignored, but they still exist.


Hey, how about a new CB voodoo term...
Seasonally Adjusted Power.
No? How about:
Seasonally Adjusted Bird Watts.

Come on, James... laughter may just save you from being
sent suicidal by this group.


Regards,
Peter.

Bottom line... it works as advertised. The ebay feedback supports
that...
http://feedback.ebay.com/ws/eBayISAP...d=260154735664
Whether you believe it or not is of little consequence...
www.telstar-electronics.com

Peter

I quote your message:

"Amplitude Modulation... The output level "swings" above
and below the carrier level."

This is incorrect. The output does not swing above and below the
carrier. The output of an AM signal is the carrier and the two
sidebands.

Also power meters are not, per se, frequency specific. There are
tricks that allow psuedo peak reading to see the "swing" that comes
with modulation. Usually this is done by using larger value capacitors
in rectified output of the RF detectors. The problem is all RF is
rectified to a time varying DC level that corresponds somewhat to the
varying amplitudes of the RF signals being sampled.

james


On Tue, 4 Sep 2007 05:53:47 +0100, " Peter"
wrote:

|
|"james" wrote...
| " Peter" wrote:
|
| |Amplitude Modulation... The output level "swings" above
| |and below the carrier level.
| |
| |Get it yet?
| |
| |If the output level does not swing, then you have a constant
| |amplitude... no amplitude modulation.
| |No amplitude modulation = no audio. Unless, of course,
| |you are using FM.
| |----------------
|
| Wrong
|
|Once again you appear to have misread my statement,
|making it appear that we disagree.
|
|Before going on, read the quote (above) and note that:
| I said output... NOT carrier.
| I did NOT say that average power changes.
|
| Unless you are using a peak reading wattmeter the power
| remians constant
|
|The power is not affected by the type of meter, all that
|changes is the type reading that you take.
|
| with modulation in a DSB-AM Large Carrier signal. IF you were
| to do a Fourier Transform of the AM signal under modulatioin
| you will see a carrier frequency, the upper sideband frequencies,
| and the lower sideband frequencies.
|
|There is no dispute that extra power is now in the sidebands,
|but the output is varying over time, as an oscilloscope would
|show.
|The total power is varying with the modulating signal but,
|as it should be swinging about the carrier level, the
|average should be constant.
|
|Surely we agree: the peak output (not carrier or average)
|is varying over time, while the average power is constant.
|At least is should be, if all is well and nobody has been
|fekkin about inside the radio.
|
| With an averaging wattmeter you should see little
| or no movement of the power.
|
|Of course not, the meter is intentionally ignoring them.
|By averaging the reading, you are removing the short term
|variations... but that does not mean they are not there.
|
|Just like a business looking at average sales - the seasonal
|fluctuations are ignored, but they still exist.
|
|
|Hey, how about a new CB voodoo term...
| Seasonally Adjusted Power.
|No? How about:
| Seasonally Adjusted Bird Watts.
|
|Come on, James... laughter may just save you from being
|sent suicidal by this group.
|
|
|Regards,
|Peter.
|
|

On Sep 2, 11:08 pm, james wrote:
rubbish.

Use your own material... lol
www.telstar-electronics.com

On Tue, 04 Sep 2007 16:09:43 -0700, Telstar Electronics
wrote:

|On Sep 2, 11:08 pm, james wrote:
| rubbish.
|
|Use your own material... lol
|www.telstar-electronics.com
|
|--------------

then how about Canine excrement?

james