On Sun, 26 Aug 2007 22:00:15 -0700, cmdr buzz corey
wrote:

|On Aug 26, 7:22 am, Telstar Electronics
|wrote:
| On Aug 26, 12:12 am,cmdr buzz
| wrote:
|
| To get the average modulation to 100% then you have to be
| overmodulating.
|
| Absolutely not!
| If you hold the modulation right at 100%... guess what the average
| is... lolwww.telstar-electronics.com
|
|You can modulate over 100% on positive peaks, assuming the power
|supplied to the final final amp stage being modulated can handle the
|extra power without clipping the envelope, but you can't go over 100%
|on negative peaks without distortion. So to get an average modulation
|of 100% with reasonable signal quality you would have to over modulate
|on positive peaks and never go over 100% on negative peaks. I doubt
|your processor nor any cb can handle that. So you can't just "hold the
|modulation at 100%".
|-------------

Yes there is was a technique used in the early days of AM called
supermodulation. That is where the positive peaks of the wavform could
exceed 100% but the negative peaks still cannot.

This is still not yielding an average of 100%.

james

On Mon, 27 Aug 2007 02:55:26 -0700, Telstar Electronics
wrote:

|On Aug 26, 7:50 pm, james wrote:
| It maybe possible to get to 100% average modulation without
| overmodulation. Still such a signal is really unitelligable and not
| worth the effort to achieve it. A voice so compressed that the peakto
| average amplitudes are equal will more than likely yield a totally
| unitelligable signal.
|
|Absolute nonsense. Why do you think that sustaining 100% modulation
|will render the signal unintelligible? The modulation percentage has
|to do with the level of modulation applied to the transmitter. As long
|as you stay below overmodulation (100%) then if the modulation signal
|has not been clipped... or waveshape altered in any way except size...
|then your modulation will be perfect... and it will contain all the
|intelligence it had originally. Not only can it be done... people who
|have VoiceMax do it every day.
|www.telstar-electronics.com
|
|---------------------

Brian

Here is the jeopardy question for you:

In the category of electronics for $100

Name the only signal that has the same value for its peak and average
value?

Now if you can answer that correctly, then you will understand why a
modulating signal that yields both 100% modulation on its peak and its
average is unitelligable.

If you answer that then we might go onto electronics for $200.


james

On Aug 28, 7:21 pm, james wrote:
On Mon, 27 Aug 2007 02:55:26 -0700, Telstar Electronics

wrote:

|On Aug 26, 7:50 pm, james wrote:
| It maybe possible to get to 100% average modulation without
| overmodulation. Still such a signal is really unitelligable and not
| worth the effort to achieve it. A voice so compressed that the peakto
| average amplitudes are equal will more than likely yield a totally
| unitelligable signal.
|
|Absolute nonsense. Why do you think that sustaining 100% modulation
|will render the signal unintelligible? The modulation percentage has
|to do with the level of modulation applied to the transmitter. As long
|as you stay below overmodulation (100%) then if the modulation signal
|has not been clipped... or waveshape altered in any way except size...
|then your modulation will be perfect... and it will contain all the
|intelligence it had originally. Not only can it be done... people who
|have VoiceMax do it every day.
|www.telstar-electronics.com
|
|---------------------

Brian

Here is the jeopardy question for you:

In the category of electronics for $100

Name the only signal that has the same value for its peak and average
value?

Now if you can answer that correctly, then you will understand why a
modulating signal that yields both 100% modulation on its peak and its
average is unitelligable.

If you answer that then we might go onto electronics for $200.

james

You're gonna make him sprain his brain with that one.

"cmdr buzz corey" wrote...
On Aug 25, 7:41 am, "vince" wrote:

No one has actually reviewed it or said they have fitted
it - they only describe how well the package was wrapped
or if it arrived. Show me one person that has fitted the
unit and aligned it correctly using test equipment, then show
the displays on a spectrum analyser and I would like to
see the FM deviation display.

That is far beyond any cber's ability. IF they can get it
installed they will crank everything up to the max to make
sure they get all the "swang" on the meter they can and
splatter across all channels.

There's no swang with FM CB. No swang, no "talk power", no
bandwidth for speech processors... and no point to having one.

FM has a constant carrier level. You cannot see the deviation
on a scope, and very few people here have deviation meters.
That includes CB shops, so there is very little chance that
they will be correctly set to the legal maximum deviation.

With just 10KHz spacing, FM CB is extremely open to distortion
and splatter problems.
Those who do not totally distort or splatter, may well do so on
their peaks. The odd short farting noise may not be a problem,
but what if they are set to a constant max?
Obviously, they will then constantly distort and take out other
channels.

The UK has been there, seen it... and we have the T-shirts
to prove it.

I will not argue with those who whimper on about
"talk power" on AM and SSB, but FM simply does
not work by "talk power".
With FM, getting your voice heard over distance
is NOT done by increasing audio. That just distorts
and splatters.

There is a solution, and it does not use processing or
expensive circuits. I have often used the method to
great effect, at a cost of pennies.
I wonder if the Griff man can educate the group on
this method.
Ah, but wait, if Brian tells us how to do this for pennies,
how will he sell his FM splatter box to people in the UK?


Regards,
Peter.

"Telstar Electronics" wrote in message...

VoiceMax actually doubles the power of any CB by taking
the average modulation to 100%.


You say *any* radio, but you have clearly stated that you are
now aiming this product at the UK market. Can you show that
you can increase FM power by increasing the modulation?
Of course not, FM has a constant carrier level.

Besides which, anything which doubles the power of a
UK CB is ILLEGAL. Any deviation in power is also
illegal - only the frequency or phase may deviate.

People in the UK have previously been fooled by "talk power"
claims from the US of A, not knowing that it does NOT apply
to their FM CBs.
The results were chaos... channels wiped out all over the place.

You should either moderate your claims, allowing for the
FM CB market that you are targeting, or drop the FM market.


Regards,
Peter.

"Telstar Electronics" wrote...

there are several CB shops across the US (and I'm in the
process of arranging one in the UK)

There goes the neighborhood.

Listen carefully, Griff. I understand that, being a Yank,
you will not know about our systems, laws and issues
regarding such devices on FM CB.
So, please allow me to inform you of some very important
facts...


UK CB is FM only.

There is no "talk power" with FM, it is a constant carrier
level (unless some tw@t has f'ked the radio up).

Increasing audio level does NOT increase the distance
of your signal.

There are only 10KHz between channels.
FM withing 10KHz spacing is a f'king tight fit.

So tight that the legal deviation level was reduced
in an attempt to stop the splatter problems.

So tight, that the latest radios must have very narrow
receive bandwidth to pass the test - yes, they must be
tested by government approved labs before being
legal here.

This narrow bandwidth will distort the signal of anyone
attempting to increase their transmitted audio.
This distrotion will not show on an oscilloscope or other
test device, as it is generated within the legal FM CB
receiver.


We have had several years where such devices were used
on FM CB, and the results were distortion and splattering
of other channels.
One person I knew actually got complaints of "bleedover"
from 20 to 30 miles away... she became famous for it
across a large part of the next county.

While specific equipment may not be illegal here, radios
pass their test with the original microphone. Adding a speech
processor may invalidate that approval - making the owner
open to prosecution for any interference caused.


Read my lips...
With FM CB, speech processors are worse than pointless... they
cause distortion and interference without any real gain.


Regards,
Peter.

james wrote:

Brian

Here is the jeopardy question for you:

In the category of electronics for $100

Name the only signal that has the same value for its peak and average
value?

Now if you can answer that correctly, then you will understand why a
modulating signal that yields both 100% modulation on its peak and its
average is unitelligable.

If you answer that then we might go onto electronics for $200.


james

I believe the answer is: CW.

On Aug 28, 11:24 pm, " Peter" wrote:
There is no "talk power" with FM, it is a constant carrier
level (unless some tw@t has f'ked the radio up).
Increasing audio level does NOT increase the distance
of your signal.

Absolute rubbish...
If you don't have enough freq deviation... you will not get out well
on FM... and your range will be decreased. I suggest you review
http://en.wikipedia.org/wiki/Frequen...dulation_index for
details. Bottom line... if you can hold the optimum deviation level on
FM... you will get out better without splattering. This is what
VoiceMax can accomplish.
www.telstar-electronics.com

"Telstar Electronics" wrote...

Well... you may be right about the first part... lol
But as far as getting as much swing... that would be a neat trick
with an audio device AGC such as VoiceMax. You see the AGC
holds the modulation up no matter what level the input is...
therefore no swing... just constant maximum modulation output.

Let me get this right...
Modulation without swing... the carrier is AM modulated,
without any "swing" in the output?

No swing, a constant output level. Yet you have AM
modulation... output level swing.


VoiceMax actually doubles the power of any CB

Any CB - even FM CB radios, such as those here in the UK?


by taking the average modulation to 100%.


How does the VoiceMax recognise 100% modulation?
Does it not simply hold it at whatever maximum the person with
the screwdriver sets the radio to? You know, the guy who you
told to crank thre radio up when fitting the VoiceMax.


Regards,
Peter.

On Aug 29, 11:37 pm, " Peter" wrote:
How does the VoiceMax recognise 100% modulation?
Does it not simply hold it at whatever maximum the person with
the screwdriver sets the radio to? You know, the guy who you
told to crank thre radio up when fitting the VoiceMax.

Yes... Voicemax has an adjustable fast-acting limiter. During the set
up (see http://www.telstar-electronics.com/VoiceMax%20B.pdf) this
limiter is adjusted so the output envelope (AM) is at 100% modulation
during speech. On FM... it's obviously the deviation that is set for
the maximum allowable bandwidth. VoiceMax will then hold these levels
from then on... regardless of the speech input level. The one
exception is below the point where the user adjusts the noise-gate
threshold. This is a point... below which the audio is muted
significanly. This is a necessary feature in a very high gain (+60dB)
AGC circuit to eliminate amplifying low level background noise to
limiting levels. So what you end up with is very potent undistorted
audio... with no background hissing. This is extremely effective in a
mobile environment.
www.telstar-electronics.com