"james" wrote...
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.

So? How are the sidebands excluded from "output level" in
my statement which you quote, but change (twice missing out
the word 'level') within your reply text?

Is this your problem, you only see the words you want to?
Then, considering output as being output frequency, rather
than output level, you see an incorrect statement.

Now, going back to my original statement, that output
level (amplitude) "swings" (varies) above and below the
carrier level (the amplitude of the unmodulated carrier)...

http://upload.wikimedia.org/wikipedi...modulation.png
http://robotics.eecs.berkeley.edu/~s...1_figure27.gif
http://robotics.eecs.berkeley.edu/~s...1_figure37.gif
http://www.st-andrews.ac.uk/~jcgl/Sc...part9/fig1.gif
http://upload.wikimedia.org/wikipedi...ignals.svg.png

Also power meters are not, per se, frequency specific.

I made no mention of readings on a specific meter, just
the actual output. Whatever you read on a meter does
NOT change what the transmitter is actually putting out.

Just like the last time, you appear to be either getting
ahead of yourself or totally changing the topic.
I am still unsure whether you are doing this on purpose,
just for the sake of arguing, or have been snorting something.

The problem is all RF is rectified to a time varying
DC level

What you do with a signal, once you receive it, makes
no difference to what is actually being transmitted.

that corresponds somewhat to the varying amplitudes
of the RF signals being sampled.

What varying amplitudes, you said it doesn't... and
you can prove it by measuring the average.

I really am having a hard time taking you seriously. Not
only do you start ranting about things that have nothing
to do with the issue (also commented on by someone else
on the group), but you then go back on your whole
argument.

I really do have to consider the possibility that you are
simply trying to wind people up and, like the Griffter,
you will say anything that you believe will achieve your
goal.


Regards,
Peter.

wrote...
On Thu, 06 Sep 2007 08:40:04 -0700, Telstar Electronics
wrote:

On Sep 6, 7:31 am, james wrote:
All audio power does is increase deviation. Using a
compressor on FM just increase average deviation.

Exactly, and I claim that having that increased average
deviation is an advantage on FM.

can you reference a citation to suport that contention (not
sure either way myself

No, Griffter can only give stock, salesman type replies.
You want facts, here you go...

The UK CB system, which we have used for 25 years, has:
10KHz spacing
3KHz typical audio bandwidth
2.5KHz deviation on old sets.
2KHz deviation on recent sets.
The list of UK and EU CB frequencies are he
http://www.citizensband.radiouk.com/...freq/index.php
http://www.citizensband.radiouk.com/...req/eufreq.php

Using Griffter's own reference to prove his lies, Carson's
Rule makes the bandwidth:
11KHz for old spec. sets.
10KHz for new spec. sets.
You can also check this using the Bessel functions...
http://en.wikipedia.org/wiki/Frequency_modulation
http://en.wikipedia.org/wiki/Carson_bandwidth_rule


As is obvious, that takes your sidebands clear into the
next channel. The only reason that this is acceptable is
because this is the peak bandwidth, occuring at peaks in
deviation.

The odd short burst of interference caused by a peak can
go unnoticed but, if the whole signal is sat at maximum
deviation, a constant 100% deviation will make it take
that bandwidth constantly.

By increasing the average deviation, he is increasing the
average power contained in the sidebands which fall
within adjacent channels - wiping those channels out.


To receive the signal clearly, it must remain within your
receiver bandwidth - that falling outside will be lost.
Just like with the splatter, you can stand a small amount
of loss on the peaks without too much trouble. Increasing
the average deviation can increase the amount of signal
going beyond this passband, increasing the audio distortion.

His 1% distortion claim goes out the window. Whatever
distortion that increased audio causes within the transmitter
and receiver are additional, add them all together.

In order to stop the continuous problems of adjacent channel
splatter that we suffered, the UK government had to make
changes to the CB specifications...
Deviation reduced.
Receive bandwidth legal requirement.
Unfortunately, this narrow RX bandwidth requirement also
made it easier to get your audio distorted by the receiver.


The Griffter is one of two things:
A fake: Knowing no real facts, simply chanting whatever he
thinks will make the sale.
A lying, cheating scammer: Knowing the true facts, but
purposely lying to make sales.

Personally, I believe he is just a fake, a salesman who will say
anything to sell his outdated product. He picks up the odd
word or phrase, like modulation index or RoHS, and just
chants it in the hope of impressing the living shyte out of
most CB users.
He doesn't really understand the words, theory or how it all
works - he just shouts words to sound like he does. Come back
at him with real facts, and he goes into his standard spam
message as a reply.


Regards,
Peter.

On Sep 8, 11:30 pm, " Peter" wrote:
wrote...
On Thu, 06 Sep 2007 08:40:04 -0700, Telstar Electronics
wrote:

On Sep 6, 7:31 am, james wrote:
All audio power does is increase deviation. Using a
compressor on FM just increase average deviation.

Exactly, and I claim that having that increased average
deviation is an advantage on FM.

can you reference a citation to suport that contention (not
sure either way myself

No, Griffter can only give stock, salesman type replies.
You want facts, here you go...

The UK CB system, which we have used for 25 years, has:
10KHz spacing
3KHz typical audio bandwidth
2.5KHz deviation on old sets.
2KHz deviation on recent sets.
The list of UK and EU CB frequencies are he
http://www.citizensband.radiouk.com/...freq/index.php
http://www.citizensband.radiouk.com/...req/eufreq.php

Using Griffter's own reference to prove his lies, Carson's
Rule makes the bandwidth:
11KHz for old spec. sets.
10KHz for new spec. sets.
You can also check this using the Bessel functions...http://en.wikipedia.org/wiki/Frequen...bandwidth_rule

As is obvious, that takes your sidebands clear into the
next channel. The only reason that this is acceptable is
because this is the peak bandwidth, occuring at peaks in
deviation.

The odd short burst of interference caused by a peak can
go unnoticed but, if the whole signal is sat at maximum
deviation, a constant 100% deviation will make it take
that bandwidth constantly.

By increasing the average deviation, he is increasing the
average power contained in the sidebands which fall
within adjacent channels - wiping those channels out.

To receive the signal clearly, it must remain within your
receiver bandwidth - that falling outside will be lost.
Just like with the splatter, you can stand a small amount
of loss on the peaks without too much trouble. Increasing
the average deviation can increase the amount of signal
going beyond this passband, increasing the audio distortion.

His 1% distortion claim goes out the window. Whatever
distortion that increased audio causes within the transmitter
and receiver are additional, add them all together.

In order to stop the continuous problems of adjacent channel
splatter that we suffered, the UK government had to make
changes to the CB specifications...
Deviation reduced.
Receive bandwidth legal requirement.
Unfortunately, this narrow RX bandwidth requirement also
made it easier to get your audio distorted by the receiver.

The Griffter is one of two things:
A fake: Knowing no real facts, simply chanting whatever he
thinks will make the sale.
A lying, cheating scammer: Knowing the true facts, but
purposely lying to make sales.

Personally, I believe he is just a fake, a salesman who will say
anything to sell his outdated product. He picks up the odd
word or phrase, like modulation index or RoHS, and just
chants it in the hope of impressing the living shyte out of
most CB users.
He doesn't really understand the words, theory or how it all
works - he just shouts words to sound like he does. Come back
at him with real facts, and he goes into his standard spam
message as a reply.

Regards,
Peter.

You are nothing more that a "spoiler". You don't have a shred of
evidence for the points you harp on most.
I, on the other hand have a tangible product with many positive
feedback entries on ebay.
Let me guess... you're right... and the whole world's wrong... lol
cheers,
www.telstar-electronics.com

Peter

All of these depict an AM signal in the time dommain. This is not the
actual representation of the modulated signal. What you are seeing is
a complex addition of the three components of the AM signal versus
time. Anyone with an engineering degree from an accredited university
would know that. What your are seeing is not the frequency compents of
the AM signal itself. To see that properly requires a spectrum
analyzer. That will display the Fourier Transform of the many links
you have posted. In the frequency domain you will see that the carrier
remains canstant while the sideband amplitudes will varying as speech
varies. In the frequency domain you will see power versus frequency.
This is what your receiver sees, power versus frequency.

Oscilloscope representations are usefull in determining modulation
levels and not actually what is happening with the AM signal. To truel
see that requires a spectrum ananlyzer.

james

On Sun, 9 Sep 2007 05:30:47 +0100, " Peter"
wrote:

|"james" wrote...
| 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.
|
|So? How are the sidebands excluded from "output level" in
|my statement which you quote, but change (twice missing out
|the word 'level') within your reply text?
|
|Is this your problem, you only see the words you want to?
|Then, considering output as being output frequency, rather
|than output level, you see an incorrect statement.
|
|Now, going back to my original statement, that output
|level (amplitude) "swings" (varies) above and below the
|carrier level (the amplitude of the unmodulated carrier)...
|
|http://upload.wikimedia.org/wikipedi...modulation.png
|http://robotics.eecs.berkeley.edu/~s...1_figure27.gif
|http://robotics.eecs.berkeley.edu/~s...1_figure37.gif
|http://www.st-andrews.ac.uk/~jcgl/Sc...part9/fig1.gif
|http://upload.wikimedia.org/wikipedi...ignals.svg.png
|
| Also power meters are not, per se, frequency specific.
|
|I made no mention of readings on a specific meter, just
|the actual output. Whatever you read on a meter does
|NOT change what the transmitter is actually putting out.
|
|Just like the last time, you appear to be either getting
|ahead of yourself or totally changing the topic.
|I am still unsure whether you are doing this on purpose,
|just for the sake of arguing, or have been snorting something.
|
| The problem is all RF is rectified to a time varying
| DC level
|
|What you do with a signal, once you receive it, makes
|no difference to what is actually being transmitted.
|
| that corresponds somewhat to the varying amplitudes
| of the RF signals being sampled.
|
|What varying amplitudes, you said it doesn't... and
|you can prove it by measuring the average.
|
|I really am having a hard time taking you seriously. Not
|only do you start ranting about things that have nothing
|to do with the issue (also commented on by someone else
|on the group), but you then go back on your whole
|argument.
|
|I really do have to consider the possibility that you are
|simply trying to wind people up and, like the Griffter,
|you will say anything that you believe will achieve your
|goal.
|
|
|Regards,
|Peter.
|

"Telstar Electronics" wrote...

You are nothing more that a "spoiler".

Ah, Diddums... having his scam spoiled.

You don't have a shred of evidence for the points you
harp on most.

I realise that all the spamming must make you tired, but
do try to keep your eyes open...

The list of UK and EU CB frequencies are he
http://www.citizensband.radiouk.com/...freq/index.php
http://www.citizensband.radiouk.com/...req/eufreq.php
What, my word not good enough? Try the official Ofcom
list he
http://www.ofcom.org.uk/radiocomms/i...binfosheet.pdf
The MPT1382 UK CB legal specifications are he

http://64.233.183.104/search?q=cache...ublication/mpt
/mpt_docs/1382newh.doc+MPT+1382&hl=en&ct=clnk&cd=1&gl=uk

FM, bandwidth and Bessel functions are he
http://en.wikipedia.org/wiki/Frequency_modulation
An easy, rough guide bandwidth calculation is he
http://en.wikipedia.org/wiki/Carson_bandwidth_rule

The evidence is there, simply use the above to calculate
the bandwidth of UK FM CB.
It's not rocket surgery, Brian. If you really are the
tech. you claim to be, the problems with speech processing
on NBFM CB radio should be damn obvious.

I'll give you a clue, using Carson's rule...
FM Bandwidth = 2(Fd+Fm):
= 2(2.5KHz + 3KHz)
= 2(5.5KHz)
= 11KHz bandwidth requirement.

Now look at the frequency charts (or the MPT1382 spec)...
11KHz takes your signal right through each adjacent
channel bandwidth.

As the 2KHz deviation is the maximum allowed (the old
spec radios, MPT1320, are 2.5KHz), this is only the
bandwidth at your audio peaks.
But, according to you, your product is designed to hold
the modulation at this peak level - so that bandwidth
will be required continuously.

Now consider the receive bandwidth of a UK FM CB (legal
requirement, stated in the MPT1382 link above)... 60dB adjacent
channel rejection.
Those sidebands, while directly in the bandwidth of anyone
on the adjacent channel, should be greatly attenuated by a
legal specification UK CB.
That explains both the distortion and splatter that can be
heard on a regular basis on UK FM CB.


So, how about the legal position of your product within
the UK?
First of all, you have still not confirmed whether it
complies with our RoHS requirements. If not, then
it is illegal to place it on the market here.

Now, use on CB:
The legal requirements, MPT1382 (link above), state that:
5.2.5 Adjacent channel power
The adjacent channel power shall not exceed
a value of 20 microwatts.

The adjacent channel power is defined in section 8.5.2.
This states 5.75KHz from the carrier, making the it
(for legal purposes) the average power contained in
the top end of the 2nd sideband plus all the power
in the sidebands above that.

By increasing the average audio, you increase the
average power in the sidebands. This is basic stuff.
This guy states it in his sales pitch...
http://www.spectrumcomms.co.uk/cbkits.htm#SP1000
Notice, also, that he states SSB and AM use - he does
NOT promote it for FM CM use. If he considered it
suitable for UK FM CB, he would say so - he has been
selling to UK CBers and CB dealers for years.

Your product can take a UK FM CB beyond the legal
specification, making it illegal to use and possibly
subject to seizure by Ofcom. There may also now
be on-the-spot fines.

There are reasons for this average adjacent power
specification, and I already gave them... occasional
short bursts onto the adjacent channel may go
unnoticed, but a high average or constant 3rd and
4th sideband content can cause serious problems.


I, on the other hand have a tangible product with
many positive feedback entries on ebay.

Sure, Acorah can speak to the dead, Blaine can fly,
and Angel can take a woman and pull her in half... all
proved by the feedback of witnesses.
Oh yes, and strap a magnet to your car fuel-line, and
your fuel consumption will be greatly reduced.
How about magnetic cups, proved to cure diseases my
"charging" the water particles.

Clearly, feedback is not reliable enough to be considered
"proof". How about some scientific facts? How about
proving that the last 26 years of UK FM CB never really
happened.

and the whole world's wrong...

That, like all your other posts, is a load of misleading
bull droppings. You do NOT have "the whole world"
agreeing with you. The "whole world" has not tried
your SplatterMax on FM CB.

Someone only has to look at the messages in this group
to see that many disagree. It wasn't me who called your
product "garbage" or made suggestions about basket
weaving. I only state that your product is not suitable
for FM CB... many other people are rather more critical
of you and your product.

Everyone who has used FM CB in the UK for some years
will know that distortion and adjacent channel splatter
are a real problem.
Those using the products may not realize, they cannot
hear the crap they are putting out.


Regards,
Peter.

"james" wrote...
Peter

All of these depict an AM signal in the time dommain.

Exactly, amplitude variations over time... modulation (AM).

This is like pulling teeth.

Oscilloscope representations are usefull in determining
modulation levels

Exactly... modulation (AM) levels.

Several teeth, without anaesthetic.

and not actually what is happening with the AM signal. To
truel see that requires a spectrum ananlyzer.

Wrong.

The instrument of choice depends upon exactly what it
is you want to know about the signal. The spectrum analyzer
does not tell you everything you may wish to know. Otherwise,
all other instuments would now be obsolete.

As you stated above, the oscilloscope IS useful for
determining modulation... which is what this was all about.
That was, until you decided to whine on about what the
sidebands are doing.

The spectrum analyzer will show you the sidebands, but if
you want to see the modulation (AM) then the oscilloscope
is the tool for the job.

Different tools for different purposes.

Come on James, this has to be a game you are playing. I really
don't have time for such games - do you?


Regards,
Peter.

On Sun, 16 Sep 2007 18:47:06 +0100, " Peter"
wrote:

|"james" wrote...
| Peter
|
| All of these depict an AM signal in the time dommain.
|
|Exactly, amplitude variations over time... modulation (AM).
|
|This is like pulling teeth.
|
| Oscilloscope representations are usefull in determining
| modulation levels
|
|Exactly... modulation (AM) levels.
|
|Several teeth, without anaesthetic.
|
| and not actually what is happening with the AM signal. To
| truel see that requires a spectrum ananlyzer.
|
|Wrong.
|
|The instrument of choice depends upon exactly what it
|is you want to know about the signal. The spectrum analyzer
|does not tell you everything you may wish to know. Otherwise,
|all other instuments would now be obsolete.
|
|As you stated above, the oscilloscope IS useful for
|determining modulation... which is what this was all about.
|That was, until you decided to whine on about what the
|sidebands are doing.
|
|The spectrum analyzer will show you the sidebands, but if
|you want to see the modulation (AM) then the oscilloscope
|is the tool for the job.
|
|Different tools for different purposes.
|
|Come on James, this has to be a game you are playing. I really
|don't have time for such games - do you?
|
|
|Regards,
|Peter.
|
|-----------

AM is a complex signal made up of many sinusoidal waveforms that can
only be seen in their individual components with a spectrum analyzer.
IF you know how to use one it will yield far more information about
your AM signal than an osscilloscope could ever yield. IF you know how
to use a spectrum analyzer, you can determine percentage of
modulation, ie modulation index, as well as the power of all three
components. Not hardly capable with an oscilloscope. The oscillocope
is best for those less technically inclined to depict what is
happening with an AM signal.

You have no time for games? Then why bother with this group?

james

"james" wrote...

The oscillocope is best for those less technically inclined
to depict what is happening with an AM signal.

Codswallop

I have worked for manufacturers, service agents and service
departments... and they all have had oscilloscopes available
and in use. They have also a range of other test equipment,
including analyzers and some rather basic equipment, in use.
One was still using some old tube type test equipment... it may
have been older than me. The task it was used for could also
be done with much more modern and expensive test equipment
but, equally, it did not need such equipment.

Other test equipment, such as analyzers, can be seen in use by
factory production staff who have absolutely no electronic
qualifications. These staff cannot tell one end of a diode
from another, but they are cheap labor.
Lack of knowledge does not stop them from using such
equipment for it's purpose.

I have never known a company or their staff select a piece
of test equipment based on whether they can use it. In reality,
the choice of test equipment comes down to other factors
such as cost and requirements for the job.

Not only are there the purchase costs, but then the regular
calibration costs. More expensive equipment generally costs
more to have calibrated or serviced.
A company will generally have a range of equipment available,
each for it's own purpose. If an engineer ties up an expensive
piece of test equipment to carry out a simple measurement, he
is likely to get his ass kicked when someone complains it is
not there and they really need it.

You also have to remember that time is money. If you can
get the reading quickly on a basic peice of test equipment,
why waste time?

Was you aware that the CB legal specification, MPT1382, actually
states that an oscilloscope should be used for certain tests? Any
UK CB must pass these tests before it can be placed on the market.

Then why bother with this group?

The answer is out there to be seen. Even the Griffter caught on
to it, and did his homework.

I can see how it could be difficult for some people to
understand - those who only use the group to play games with
CB users, rather like a cat plays with a mouse before leaving
it for dead.

Are you one of those people, who only come here to mess with
the minds of those genuinely interested in CB?


Regards,
Peter.

On Wed, 26 Sep 2007 05:56:39 +0100, " Peter"
wrote:

"james" wrote...

The oscillocope is best for those less technically inclined
to depict what is happening with an AM signal.

Codswallop


such langauge

"one useless man is disgrace 2 become a law firm 3 or more become a congress"
adams

woger you are a Congress all in your own head

http://kb9rqz.bravejournal.com/

and get ou the newly recovered KB9RQZ.blogspot.com as well

G

--
Posted via a free Usenet account from http://www.teranews.com

wrote...
" Peter" wrote:

Codswallop

such langauge

It is in the Collins dictionary.

Damn PC Brigade will not be happy until they ban the whole of
the English language. Did you know that a UK local government
department banned the use of certain four letter words... like "Lady".

Seriously, it was one of a list of common English words they said
may offend people.
What a load of shoe repair people.


Regards,
Peter.