Radium,

Some television is actually transmitted using FM modulation schemes, but not
for commercial broadcasting. Examples of FM TV are ham/amateur ATV/SSTV,
unlicensed 2.4 GHz surveillance links, and a number of point to point and
studio to transmitter systems. FM signaling provides benefits in noise
immunity and also permits better channel re-use, since it exploits one of
the best features of FM called "the FM capture effect", wherein nearly equal
strength signals which would otherwise interfere in AM systems will cause an
FM receiver to "capture" only the stronger signal and ignore the weaker,
even if differences of 1 dB of signal strength exists.

There is no specific answer to what you would see as far as video patterns,
and there is no reason whatsoever to expect to see sawtooth waveforms in
particular. The demodulated signal from FM will conform to the spectral
changes just as the demodulated signal from an AM detector would conform to
amplitude changes, and random noise would be considered "snow" in either
case. Unless a transmitted signal with a frequency ramp (sometimes called "a
chirp") is present, the video would have no sawtooth. A Doppler radar, for
example, could generate such a waveform, since some radars create chirped /
swept signals. The video scan rate(s) would additionally need to be in the
range of the chirp rate to create the appearance of a sawtooth.

FM disturbances in the SHF band are likely to be man-made and not
atmospheric, and thus only "viewable" if the "FM Video Receiver" you
envision had a demodulator / discriminator whose bandwidth was tailored to a
specific transmitted waveform, and even then only if sweep rates were
suitable. Absent a man-made transmitter, the SHF environment is mostly
thermal noise (both circuit and atmospheric) and only a radio telescope or
other enormous aperture / antenna will see beyond the atmosphere.

The choice of using AM versus FM is really way more complicated than "AM for
audio" or "FM for digital video". When designing communication systems of
any type, the engineer is faced with balancing many issues, and the channel,
media, noise environment, interference sources, power budget, multipath,
complexity, and cost are only a few of the considerations involved. A highly
reliable cable modem to transmit fast digital content may indeed by phase
modulated with an amplitude trellis; a secure and interference resistant
link may use spread-spectrum frequency hopping AM for digital signaling; and
FM winds up being used heavily in many voice communication systems mostly
because the capture effect reduces co-channel interference.

The closest I can suggest to what you might enjoy exploring would be a
satellite dish and receiver designed for L band which will see and decode
some broadcasting which is unprotected / unencrypted. It gets you into the
range of SHF, has true TV signaling for public viewing, and is a hobbyist
activity with others involved.

Smarty






"Radium" wrote in message
ups.com...
Hi:

Video signals for NTSC, PAL, and SECAM television are transmitted on
AM carriers.

My question is, let's say I have a television set that is capable of
receiving and demodulating FM video carrier waves. What would I see on
the TV? I am aware that no company uses FM video. Would I see sawtooth-
like patterns on the screen due to frequency-modulated electric fields
present in the environment?

I'd really like buy a TV with a FM-video receiver; I want to find out
what FM-video disturbances in the SHF [Super High Frequency ]
frequency-range look like. I am sick n' tired of AM video.

AM should be used for analog audio. FM should be used for digital
video.


Regards,

Radium

On Jun 6, 10:35 pm, "Smarty" wrote:
Radium,

Some television is actually transmitted using FM modulation schemes, but not
for commercial broadcasting. Examples of FM TV are ham/amateur ATV/SSTV,
unlicensed 2.4 GHz surveillance links, and a number of point to point and
studio to transmitter systems. FM signaling provides benefits in noise
immunity and also permits better channel re-use, since it exploits one of
the best features of FM called "the FM capture effect", wherein nearly equal
strength signals which would otherwise interfere in AM systems will cause an
FM receiver to "capture" only the stronger signal and ignore the weaker,
even if differences of 1 dB of signal strength exists.

There is no specific answer to what you would see as far as video patterns,
and there is no reason whatsoever to expect to see sawtooth waveforms in
particular. The demodulated signal from FM will conform to the spectral
changes just as the demodulated signal from an AM detector would conform to
amplitude changes, and random noise would be considered "snow" in either
case. Unless a transmitted signal with a frequency ramp (sometimes called "a
chirp") is present, the video would have no sawtooth. A Doppler radar, for
example, could generate such a waveform, since some radars create chirped /
swept signals. The video scan rate(s) would additionally need to be in the
range of the chirp rate to create the appearance of a sawtooth.

FM disturbances in the SHF band are likely to be man-made and not
atmospheric, and thus only "viewable" if the "FM Video Receiver" you
envision had a demodulator / discriminator whose bandwidth was tailored to a
specific transmitted waveform, and even then only if sweep rates were
suitable. Absent a man-made transmitter, the SHF environment is mostly
thermal noise (both circuit and atmospheric) and only a radio telescope or
other enormous aperture / antenna will see beyond the atmosphere.

The choice of using AM versus FM is really way more complicated than "AM for
audio" or "FM for digital video". When designing communication systems of
any type, the engineer is faced with balancing many issues, and the channel,
media, noise environment, interference sources, power budget, multipath,
complexity, and cost are only a few of the considerations involved. A highly
reliable cable modem to transmit fast digital content may indeed by phase
modulated with an amplitude trellis; a secure and interference resistant
link may use spread-spectrum frequency hopping AM for digital signaling; and
FM winds up being used heavily in many voice communication systems mostly
because the capture effect reduces co-channel interference.

The closest I can suggest to what you might enjoy exploring would be a
satellite dish and receiver designed for L band which will see and decode
some broadcasting which is unprotected / unencrypted. It gets you into the
range of SHF, has true TV signaling for public viewing, and is a hobbyist
activity with others involved.

Smarty, big thanks for your detailed response. One big advantage [that
I could imagine] to using FM -- instead of AM -- to carry the
luminance (Y) signal, is that you can run on your treadmill without
seeing those lines on the screen mask your favorite shows. The
magnetic signals generated by the electronics in the treadmill causes
blinding interference on AM video. FM video is be immune to such
disruptions.

"Radium" wrote in message
ups.com...
Smarty, big thanks for your detailed response. One big advantage [that
I could imagine] to using FM -- instead of AM -- to carry the
luminance (Y) signal, is that you can run on your treadmill without
seeing those lines on the screen mask your favorite shows. The
magnetic signals generated by the electronics in the treadmill causes
blinding interference on AM video. FM video is be immune to such
disruptions.

Unless your treadmill is doing something very unusual, the interference
you are seeing is unlikely to be coming in via the RF "front end" of
the TV (where the video demodulation is taking place), and so switching
to FM from AM wouldn't help. (It's more than likely either magnetic
interference upsetting the deflection fields - assuming a CRT-type TV
- or the effects of noise coming in on the AC wiring.)

FM for standard "analog" TV is virtually impossible due to the bandwidth
requirements of typical FM itself. In the case of "digital" TV - well,
for the moment, let's just say that the modulation system used is
considerably different than anything we're talking about here, and
leave it at that, OK?

Bob M.

My compliments to Richard Crowley in his original reply. We are indeed
dealing with a troll here, admittedly a droll troll.

Smarty


"Bob Myers" wrote in message
...

"Radium" wrote in message
ups.com...
Smarty, big thanks for your detailed response. One big advantage [that
I could imagine] to using FM -- instead of AM -- to carry the
luminance (Y) signal, is that you can run on your treadmill without
seeing those lines on the screen mask your favorite shows. The
magnetic signals generated by the electronics in the treadmill causes
blinding interference on AM video. FM video is be immune to such
disruptions.

Unless your treadmill is doing something very unusual, the interference
you are seeing is unlikely to be coming in via the RF "front end" of
the TV (where the video demodulation is taking place), and so switching
to FM from AM wouldn't help. (It's more than likely either magnetic
interference upsetting the deflection fields - assuming a CRT-type TV
- or the effects of noise coming in on the AC wiring.)

FM for standard "analog" TV is virtually impossible due to the bandwidth
requirements of typical FM itself. In the case of "digital" TV - well,
for the moment, let's just say that the modulation system used is
considerably different than anything we're talking about here, and
leave it at that, OK?

Bob M.

"Bob Myers" wrote ...
Unless your treadmill is doing something very unusual, ....

We're all betting on how long it takes you to relize that you've
been trolled.

"Richard Crowley" wrote in message
...
"Bob Myers" wrote ...
Unless your treadmill is doing something very unusual, ....

We're all betting on how long it takes you to relize that you've
been trolled.

I've been here - and watching our friend Radium in action -
for quite some time. Don't care, perhaps someone will
learn something from the exchange.

Bob M.

"Bob Myers" wrote...
"Richard Crowley" wrote ...
We're all betting on how long it takes you to relize that you've
been trolled.

I've been here - and watching our friend Radium in action -
for quite some time. Don't care, perhaps someone will
learn something from the exchange.

Laudable, but consider also that you are directly
contributing to "Radium"s filling the Google archives
with misleading drivel for future readers to trip over.

Police use spy tools to spot criminals. www.clarionledger.com
(Local News)

I saw something about that on yesertay's tv news, amazing.Check out
those new fiber optic spy cameras the City of Jackson is putting up all
over town.They need to put one up on each end of the short little street
I live on.
cuhulin

Bob Myers wrote:

Unless your treadmill is doing something very unusual, the interference
you are seeing is unlikely to be coming in via the RF "front end" of
the TV (where the video demodulation is taking place), and so switching
to FM from AM wouldn't help. (It's more than likely either magnetic
interference upsetting the deflection fields - assuming a CRT-type TV
- or the effects of noise coming in on the AC wiring.)

FM for standard "analog" TV is virtually impossible due to the bandwidth
requirements of typical FM itself. In the case of "digital" TV - well,
for the moment, let's just say that the modulation system used is
considerably different than anything we're talking about here, and
leave it at that, OK?


Catel made some FM return channel modulators and demodulators for
CATV systems that fit into a standard 6 MHz channel spacing. They were
pure ****. Murky video, at best, because of the reduced bandwidth.
Metrovision had them in their community loop in Greene Township, Ohio
and were connected to the United Video Cablevision community loop in
Delhi Township, Ohio (Cincinnati, Ohio suburbs) that used standard VSB
equipment. To add insult to injury, the school system insisted that
their control point be in the Metrovision side, and they used an Apple
II computer to generate video to feed the FM modulator. It was
absolutely unreadable on any TV screen after passing through the Catel
junk. I was in charge of the United Video end of that interconnect
project. I built the headend and interconnect point with three RCA
Heterodyne Signal Processors.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Radium,

I understand how magnetic fields from your treadmill interfere with your
reception. The answer is actually quite simple. You need to run the
treadmill in reverse, namely, you provide the power and the treadmill acts
as a generator. The benefits are 3-fold:

1. The electric bill in your house will be substantially reduced, since you,
and not the motor in the treadmill, create the needed energy. Rather than
draw power from the wall, you will create a power source.

2. Your personal energy level will rise, and your ability to perform heavy
work will improve. The many contaminants which are now (apparently) clouding
your thinking process will lift, allowing you to no longer have concerns
about SHF, sawtooth waveforms, or other distractions from your basic
circulating chi. Your ying and yang will be simultaneously improved as well.

3. Finally, your TV reception will vastly improve, since this force of
treadmill magnetic flux will not only be removed, but you will generate a
positive ion flux field which will augment both AM and FM reception.

It will take you some time to learn how to run backwards on your treadmill
to achieve this generator action. Do not be disheartened......since the 3
benefits above are well worth the effort.

Always bear in mind that a small squirrel running in its' little cage can do
what you are attempting to do. It will help you to repeat the words over and
over again:


"I am a squirrel"

"I am a squirrel"

"I am a squirrel"

All of us on this newsgroup know you will be successful.

Smarty



"Radium" wrote in message
ups.com...
On Jun 6, 10:35 pm, "Smarty" wrote:
Radium,

Some television is actually transmitted using FM modulation schemes, but
not
for commercial broadcasting. Examples of FM TV are ham/amateur ATV/SSTV,
unlicensed 2.4 GHz surveillance links, and a number of point to point and
studio to transmitter systems. FM signaling provides benefits in noise
immunity and also permits better channel re-use, since it exploits one of
the best features of FM called "the FM capture effect", wherein nearly
equal
strength signals which would otherwise interfere in AM systems will cause
an
FM receiver to "capture" only the stronger signal and ignore the weaker,
even if differences of 1 dB of signal strength exists.

There is no specific answer to what you would see as far as video
patterns,
and there is no reason whatsoever to expect to see sawtooth waveforms in
particular. The demodulated signal from FM will conform to the spectral
changes just as the demodulated signal from an AM detector would conform
to
amplitude changes, and random noise would be considered "snow" in either
case. Unless a transmitted signal with a frequency ramp (sometimes called
"a
chirp") is present, the video would have no sawtooth. A Doppler radar,
for
example, could generate such a waveform, since some radars create chirped
/
swept signals. The video scan rate(s) would additionally need to be in
the
range of the chirp rate to create the appearance of a sawtooth.

FM disturbances in the SHF band are likely to be man-made and not
atmospheric, and thus only "viewable" if the "FM Video Receiver" you
envision had a demodulator / discriminator whose bandwidth was tailored
to a
specific transmitted waveform, and even then only if sweep rates were
suitable. Absent a man-made transmitter, the SHF environment is mostly
thermal noise (both circuit and atmospheric) and only a radio telescope
or
other enormous aperture / antenna will see beyond the atmosphere.

The choice of using AM versus FM is really way more complicated than "AM
for
audio" or "FM for digital video". When designing communication systems of
any type, the engineer is faced with balancing many issues, and the
channel,
media, noise environment, interference sources, power budget, multipath,
complexity, and cost are only a few of the considerations involved. A
highly
reliable cable modem to transmit fast digital content may indeed by phase
modulated with an amplitude trellis; a secure and interference resistant
link may use spread-spectrum frequency hopping AM for digital signaling;
and
FM winds up being used heavily in many voice communication systems mostly
because the capture effect reduces co-channel interference.

The closest I can suggest to what you might enjoy exploring would be a
satellite dish and receiver designed for L band which will see and decode
some broadcasting which is unprotected / unencrypted. It gets you into
the
range of SHF, has true TV signaling for public viewing, and is a hobbyist
activity with others involved.

Smarty, big thanks for your detailed response. One big advantage [that
I could imagine] to using FM -- instead of AM -- to carry the
luminance (Y) signal, is that you can run on your treadmill without
seeing those lines on the screen mask your favorite shows. The
magnetic signals generated by the electronics in the treadmill causes
blinding interference on AM video. FM video is be immune to such
disruptions.