Double Tvision

[Robin Graham]

A friend's TV has a ghost image. She lives in the New Forest and tells me
that all TVs in the area are the same because of poor reception. She has a
booster in the aerial system.

Is the ghost image due to poor reception or actually something else (which
is my feeling)? What else can be done about it? I can't believe in this day
and age that someone should have to put up with a ghost image.

Rob Graham

 

[Dana Raymond]

What you are describing is called "Multipath Distortion". Thats where an
antenna system picks up a TV picture as well as a slightly delayed, weaker
signal coming from reflections of the TV signal off of buildings. The ghost
will be to the right of the main image and will usually be faint.

NTSC TV broadcasts the picture with AM modulation, so the ghost is added
into the picture. Audio is FM radio, and the TV will lock into the stronger
TV signal - thats why ghosting only affects the image and not the sound.

Now, if this only happens on one particular station, or other stations also
have it but look different, then it probably really is multipath distortion.
However, if it occurs on all TV stations and looks the same, then I would
suspect a problem with the amplifier or cabling. If a cable is improperly
terminated (bad cable, connectors, etc.) then you can get those reflections
in the cable itself.

Assuming that she has her own antenna, amplifier, and cabling, and the
ghosting is the same on her neighbour's TV, then its definately Multipath
Distortion.

The only solution: Get a highly direction TV antenna and an antenna rotator
(available at Radio Shack!) and she can rotate the antenna to point directly
at the transmitting antenna, reducing or eliminating the ghosting.

BTW Ghosting and antenna rotators were common in the days when everyone had
their own antenna. Cable systems started out at the community level and used
seperate antennas pointing to each TV transmitter, and a combining power
amplifier for distribution to the local community. The advantage was
stronger TV signals with much less noise.

We have been spoiled!

"Robin Graham" <rttgraham@btinternet.com> wrote in message
news:chot3r$7gh$1@titan.btinternet.com...

A friend's TV has a ghost image. She lives in the New Forest and tells me
that all TVs in the area are the same because of poor reception. She has a
booster in the aerial system.

Is the ghost image due to poor reception or actually something else (which
is my feeling)? What else can be done about it? I can't believe in this
day
and age that someone should have to put up with a ghost image.

Rob Graham

 

[Robin Graham]

"Dana Raymond" <what@ever.com> wrote in message
news:KhX%c.283107$UTP.187522@twister01.bloor.is.net.cable.rogers.com...

What you are describing is called "Multipath Distortion". Thats where an
antenna system picks up a TV picture as well as a slightly delayed, weaker
signal coming from reflections of the TV signal off of buildings. The
ghost
will be to the right of the main image and will usually be faint.

NTSC TV broadcasts the picture with AM modulation, so the ghost is added
into the picture. Audio is FM radio, and the TV will lock into the
stronger
TV signal - thats why ghosting only affects the image and not the sound.

Now, if this only happens on one particular station, or other stations
also
have it but look different, then it probably really is multipath
distortion.
However, if it occurs on all TV stations and looks the same, then I would
suspect a problem with the amplifier or cabling. If a cable is improperly
terminated (bad cable, connectors, etc.) then you can get those
reflections
in the cable itself.

Assuming that she has her own antenna, amplifier, and cabling, and the
ghosting is the same on her neighbour's TV, then its definately Multipath
Distortion.

The only solution: Get a highly direction TV antenna and an antenna
rotator
(available at Radio Shack!) and she can rotate the antenna to point
directly
at the transmitting antenna, reducing or eliminating the ghosting.

BTW Ghosting and antenna rotators were common in the days when everyone
had
their own antenna. Cable systems started out at the community level and
used
seperate antennas pointing to each TV transmitter, and a combining power
amplifier for distribution to the local community. The advantage was
stronger TV signals with much less noise.

We have been spoiled!

"Robin Graham" <rttgraham@btinternet.com> wrote in message
news:chot3r$7gh$1@titan.btinternet.com...
A friend's TV has a ghost image. She lives in the New Forest and tells me
that all TVs in the area are the same because of poor reception. She has
a
booster in the aerial system.

Is the ghost image due to poor reception or actually something else
(which
is my feeling)? What else can be done about it? I can't believe in this
day
and age that someone should have to put up with a ghost image.

Rob Graham



Thanks, Dana. I've forwarded your reply to her.

Rob