Radium wrote:

...
If a carrier signal varies by anything other than just amplitude, then
it isn't AM. Right?


Let logic be your guide, again. As was pointed out earlier, the voice
freqs which modulate the carrier will cause a variance in freq (a small
fm component.)

In fm, it is not unusual for a small "amplitude modulation" to be
generated, as the varying/spanning of freq(s) is caused by the
modulation, some changes in fm carrier can be generated.

In an imperfect world, nothing is "perfect."

Regards,
JS

On 6/30/07 7:31 PM, in article , "John Smith I"
wrote:

Radium wrote:

...
If a carrier signal varies by anything other than just amplitude, then
it isn't AM. Right?


Let logic be your guide, again. As was pointed out earlier, the voice
freqs which modulate the carrier will cause a variance in freq (a small
fm component.)

This will not happen in a properly designed transmitter. It is not a
characteristic of AM.

In fm, it is not unusual for a small "amplitude modulation" to be
generated, as the varying/spanning of freq(s) is caused by the
modulation, some changes in fm carrier can be generated.

In an imperfect world, nothing is "perfect."

Regards,
JS

Don Bowey wrote:

...
This will not happen in a properly designed transmitter. It is not a
characteristic of AM.
In fm, it is not unusual for a small "amplitude modulation" to be
generated, as the varying/spanning of freq(s) is caused by the
modulation, some changes in fm carrier can be generated.

In an imperfect world, nothing is "perfect."

Regards,
JS


Listen to a "strong--pure am signal" on an fm receiver, turn up the
volume on the fm receiver, something is responsible for that ... repeat
experiment with the reverse ... "imperfect world theory" proof!

In new equip (I started out decades ago, remember) voltage regulation,
filters, suppressors have much improved ... digital processing is king
and allows what analog never could achieve ...

Regards,
JS

On 6/30/07 8:29 PM, in article , "John Smith I"
wrote:

Don Bowey wrote:

...
This will not happen in a properly designed transmitter. It is not a
characteristic of AM.
In fm, it is not unusual for a small "amplitude modulation" to be
generated, as the varying/spanning of freq(s) is caused by the
modulation, some changes in fm carrier can be generated.

In an imperfect world, nothing is "perfect."

Regards,
JS


Listen to a "strong--pure am signal" on an fm receiver, turn up the
volume on the fm receiver, something is responsible for that ... repeat
experiment with the reverse ... "imperfect world theory" proof!

You are hearing the effects of the sidebands, not the Carrier.


In new equip (I started out decades ago, remember) voltage regulation,
filters, suppressors have much improved ... digital processing is king
and allows what analog never could achieve ...

Regards,
JS

In a properly designed transmitter the Carrier amplitude does not change
with modulation. I have better tools than FM receivers to prove that fact
and theory agree for AM.

Don Bowey wrote:

...
You are hearing the effects of the sidebands, not the Carrier.

DUH! And, you only have the sidebands as a result of the
carrier/modulation ...

In a properly designed transmitter the Carrier amplitude does not change
with modulation. I have better tools than FM receivers to prove that fact
and theory agree for AM.

And the time to argue the insignificant ... sharpen that razor blade,
you can then successfully split much narrower hairs ...

JS

On 6/30/07 8:50 PM, in article , "John Smith I"
wrote:

Don Bowey wrote:

...
You are hearing the effects of the sidebands, not the Carrier.

DUH! And, you only have the sidebands as a result of the
carrier/modulation ...

So what? You implied or inferred that what was heard from the FM radio was
caused by the AM Carrier. Leave out the Carrier and you will hear the same
thing.


In a properly designed transmitter the Carrier amplitude does not change
with modulation. I have better tools than FM receivers to prove that fact
and theory agree for AM.

And the time to argue the insignificant ... sharpen that razor blade,
you can then successfully split much narrower hairs ...

It is important that we not confuse a person new to electronics by the type
of inane points you make. It doesn't matter a whit if someone's AM
transmitter Carrier shifts on power peaks due to poor regulation. It has
nothing to do with "AM" and everything to do with poor design.

Side issues don't help the new folks.



JS

"John Smith I" wrote in message
...
Listen to a "strong--pure am signal" on an fm receiver, turn up the volume
on the fm receiver, something is responsible for that ... repeat
experiment with the reverse ... "imperfect world theory" proof!

What is responsible for that is not that AM somehow also
produces FM, but simply that the type of demodulator used
by the FM receiver in question will also demodulate AM to
a usable degree. Ditto the reverse (look up "slope detection"
for an example of how a very common AM demodulator
can also demodulate FM).

Bob M.