One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.




BTW, as to loss of signal in an attic,
http://www.dennysantennaservice.com/...tallation.html
says: "A plywood roof covered by a single layer of asphalt shingles is
best.", (that is, other roofs are worse) and that's just what I have.
I'm sure it would still work better on the roof, but if I lose one or
two stations, I can accept that.

"mm" wrote in message
...
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.



That's an interesting question. I guess to some extent, it depends on the
frequency involved, and how close you are to the transmitter. I feel that
the potential losses are likely to be far worse at UHF than VHF. An example
that comes to mind is my local ATV repeater. It is sited on a hill, and I
clearly remember some of us helping out a new licensee, who was located
within line of sight of the transmitter mast, about 3/4 mile away, and at
the bottom of the hill. He could barely pick up a signal from it, and could
not access it with his own 2W transmitter at all. This was at 23cms (1.2GHz)
so a little above the top of the UHF band. We did some field strength
checks, and found that there was quite a distinct 'shadow' around the
transmitter site, out to a distance of around a mile. The repeater's antenna
is a slotted waveguide.

The first thing that we did was to re-site his antenna pair onto a taller
mast, which produced a significant improvement to his situation, but was
still not good, considering how close he was to the repeater. The final
thing that we did was to tilt his antennas up at a similar angle to the hill
itself, and this brought about the improvement to solid P5 copy and repeater
access, that we had been expecting. I believe I have read that it is common
to find this shadowing effect around high power TV transmitter masts, and
that it can extend out to several miles in some instances. Michael T could
probably comment better on this as he was involved in the industry.

So, I suppose that on paper, the answer has to be that there will be an
effect on received signal strength with the antenna tilted down, but it will
probably not be enough to notice on a modern TV set, if the signal is not
marginal and hovering on the set's AGC threshold in the first place. If you
take it to its logical conclusion, if you stood the antenna on its 'nose',
it would receive virtually nothing. At some point, horizontal or pointing
slightly *up*, you would be receiving a maximum signal. Anywhere inbetween
must, in theory at least, be less than the potential maximum.

Of course, now we're talking digital TV transmissions, all bets are off on
this ... :-)

Arfa

On Dec 1, 3:42*am, "Arfa Daily" wrote:
"mm" wrote in message

...





One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. *Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. * All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

That's an interesting question. I guess to some extent, it depends on the
frequency involved, and how close you are to the transmitter. I feel that
the potential losses are likely to be far worse at UHF than VHF. An example
that comes to mind is my local ATV repeater. It is sited on a hill, and I
clearly remember some of us helping out a new licensee, who was located
within line of sight of the transmitter mast, about 3/4 mile away, and at
the bottom of the hill. He could barely pick up a signal from it, and could
not access it with his own 2W transmitter at all. This was at 23cms (1.2GHz)
so a little above the top of the UHF band. We did some field strength
checks, and found that there was quite a distinct 'shadow' around the
transmitter site, out to a distance of around a mile. The repeater's antenna
is a slotted waveguide.

The first thing that we did was to re-site his antenna pair onto a taller
mast, which produced a significant improvement to his situation, but was
still not good, considering how close he was to the repeater. The final
thing that we did was to tilt his antennas up at a similar angle to the hill
itself, and this brought about the improvement to solid P5 copy and repeater
access, that we had been expecting. I believe I have read that it is common
to find this shadowing effect around high power TV transmitter masts, and
that it can extend out to several miles in some instances. Michael T could
probably comment better on this as he was involved in the industry.

So, I suppose that on paper, the answer has to be that there will be an
effect on received signal strength with the antenna tilted down, but it will
probably not be enough to notice on a modern TV set, if the signal is not
marginal and hovering on the set's AGC threshold in the first place. If you
take it to its logical conclusion, if you stood the antenna on its 'nose',
it would receive virtually nothing. At some point, horizontal or pointing
slightly *up*, you would be receiving a maximum signal. Anywhere inbetween
must, in theory at least, be less than the potential maximum.

Of course, now we're talking digital TV transmissions, all bets are off on
this ... * :-)

Arfa- Hide quoted text -

- Show quoted text -

Digital signals travel through space the same as analog signals at the
same frequency. The best reception is for the antenna to point
directly at the transmitter. If there are reflections, then pointing
either upward or downward from the transmitter maight improve
reception. Digital formatting of the signal may make reflections more
or less of a problem than it was with older analog signal format.

On Nov 30, 11:46*pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?

On Nov 30, 11:46*pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?

"hr(bob) " wrote in message
...
On Dec 1, 3:42 am, "Arfa Daily" wrote:
"mm" wrote in message

...





One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

That's an interesting question. I guess to some extent, it depends on the
frequency involved, and how close you are to the transmitter. I feel that
the potential losses are likely to be far worse at UHF than VHF. An
example
that comes to mind is my local ATV repeater. It is sited on a hill, and I
clearly remember some of us helping out a new licensee, who was located
within line of sight of the transmitter mast, about 3/4 mile away, and at
the bottom of the hill. He could barely pick up a signal from it, and
could
not access it with his own 2W transmitter at all. This was at 23cms
(1.2GHz)
so a little above the top of the UHF band. We did some field strength
checks, and found that there was quite a distinct 'shadow' around the
transmitter site, out to a distance of around a mile. The repeater's
antenna
is a slotted waveguide.

The first thing that we did was to re-site his antenna pair onto a taller
mast, which produced a significant improvement to his situation, but was
still not good, considering how close he was to the repeater. The final
thing that we did was to tilt his antennas up at a similar angle to the
hill
itself, and this brought about the improvement to solid P5 copy and
repeater
access, that we had been expecting. I believe I have read that it is
common
to find this shadowing effect around high power TV transmitter masts, and
that it can extend out to several miles in some instances. Michael T could
probably comment better on this as he was involved in the industry.

So, I suppose that on paper, the answer has to be that there will be an
effect on received signal strength with the antenna tilted down, but it
will
probably not be enough to notice on a modern TV set, if the signal is not
marginal and hovering on the set's AGC threshold in the first place. If
you
take it to its logical conclusion, if you stood the antenna on its 'nose',
it would receive virtually nothing. At some point, horizontal or pointing
slightly *up*, you would be receiving a maximum signal. Anywhere inbetween
must, in theory at least, be less than the potential maximum.

Of course, now we're talking digital TV transmissions, all bets are off on
this ... :-)

Arfa- Hide quoted text -

- Show quoted text -

Digital signals travel through space the same as analog signals at the
same frequency. The best reception is for the antenna to point
directly at the transmitter. If there are reflections, then pointing
either upward or downward from the transmitter maight improve
reception. Digital formatting of the signal may make reflections more
or less of a problem than it was with older analog signal format.


I see that you're well into all the media and government hype about how good
digital terrestrial TV is then, Bob ...

The (tongue in cheek) point I was making had nothing to do with the format
of the modulating signal, which of course has absolutely nothing to do with
how well or otherwise, the carrier propagates through space. I was actually
referring to less-than-ideal reception circumstances such as those the OP
suggests that he may have, which with an analogue signal, may well give
perfectly acceptable results, but with a digital signal might result in
digital cliff pixellation and freezing. Digital terrestrial TV signals are,
in my experience here in the UK, nothing like as robust, or easily received
in many transmission regions, as the government - whose primary interest
lies in how much money they can make by selling off large chunks of the UHF
TV band to cell phone operators - would have Joe public believe through
their hyped-up and often misleading media campaign directed at the subject
....

Arfa

"hr(bob) " wrote in message
...
On Dec 1, 3:42 am, "Arfa Daily" wrote:
"mm" wrote in message

...





One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

That's an interesting question. I guess to some extent, it depends on the
frequency involved, and how close you are to the transmitter. I feel that
the potential losses are likely to be far worse at UHF than VHF. An
example
that comes to mind is my local ATV repeater. It is sited on a hill, and I
clearly remember some of us helping out a new licensee, who was located
within line of sight of the transmitter mast, about 3/4 mile away, and at
the bottom of the hill. He could barely pick up a signal from it, and
could
not access it with his own 2W transmitter at all. This was at 23cms
(1.2GHz)
so a little above the top of the UHF band. We did some field strength
checks, and found that there was quite a distinct 'shadow' around the
transmitter site, out to a distance of around a mile. The repeater's
antenna
is a slotted waveguide.

The first thing that we did was to re-site his antenna pair onto a taller
mast, which produced a significant improvement to his situation, but was
still not good, considering how close he was to the repeater. The final
thing that we did was to tilt his antennas up at a similar angle to the
hill
itself, and this brought about the improvement to solid P5 copy and
repeater
access, that we had been expecting. I believe I have read that it is
common
to find this shadowing effect around high power TV transmitter masts, and
that it can extend out to several miles in some instances. Michael T could
probably comment better on this as he was involved in the industry.

So, I suppose that on paper, the answer has to be that there will be an
effect on received signal strength with the antenna tilted down, but it
will
probably not be enough to notice on a modern TV set, if the signal is not
marginal and hovering on the set's AGC threshold in the first place. If
you
take it to its logical conclusion, if you stood the antenna on its 'nose',
it would receive virtually nothing. At some point, horizontal or pointing
slightly *up*, you would be receiving a maximum signal. Anywhere inbetween
must, in theory at least, be less than the potential maximum.

Of course, now we're talking digital TV transmissions, all bets are off on
this ... :-)

Arfa- Hide quoted text -

- Show quoted text -

Digital signals travel through space the same as analog signals at the
same frequency. The best reception is for the antenna to point
directly at the transmitter. If there are reflections, then pointing
either upward or downward from the transmitter maight improve
reception. Digital formatting of the signal may make reflections more
or less of a problem than it was with older analog signal format.


I see that you're well into all the media and government hype about how good
digital terrestrial TV is then, Bob ...

The (tongue in cheek) point I was making had nothing to do with the format
of the modulating signal, which of course has absolutely nothing to do with
how well or otherwise, the carrier propagates through space. I was actually
referring to less-than-ideal reception circumstances such as those the OP
suggests that he may have, which with an analogue signal, may well give
perfectly acceptable results, but with a digital signal might result in
digital cliff pixellation and freezing. Digital terrestrial TV signals are,
in my experience here in the UK, nothing like as robust, or easily received
in many transmission regions, as the government - whose primary interest
lies in how much money they can make by selling off large chunks of the UHF
TV band to cell phone operators - would have Joe public believe through
their hyped-up and often misleading media campaign directed at the subject
....

Arfa

On Dec 1, 7:30*pm, "Arfa Daily" wrote:
"hr(bob) " wrote in message

...
On Dec 1, 3:42 am, "Arfa Daily" wrote:





"mm" wrote in message

.. .

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

That's an interesting question. I guess to some extent, it depends on the
frequency involved, and how close you are to the transmitter. I feel that
the potential losses are likely to be far worse at UHF than VHF. An
example
that comes to mind is my local ATV repeater. It is sited on a hill, and I
clearly remember some of us helping out a new licensee, who was located
within line of sight of the transmitter mast, about 3/4 mile away, and at
the bottom of the hill. He could barely pick up a signal from it, and
could
not access it with his own 2W transmitter at all. This was at 23cms
(1.2GHz)
so a little above the top of the UHF band. We did some field strength
checks, and found that there was quite a distinct 'shadow' around the
transmitter site, out to a distance of around a mile. The repeater's
antenna
is a slotted waveguide.

The first thing that we did was to re-site his antenna pair onto a taller
mast, which produced a significant improvement to his situation, but was
still not good, considering how close he was to the repeater. The final
thing that we did was to tilt his antennas up at a similar angle to the
hill
itself, and this brought about the improvement to solid P5 copy and
repeater
access, that we had been expecting. I believe I have read that it is
common
to find this shadowing effect around high power TV transmitter masts, and
that it can extend out to several miles in some instances. Michael T could
probably comment better on this as he was involved in the industry.

So, I suppose that on paper, the answer has to be that there will be an
effect on received signal strength with the antenna tilted down, but it
will
probably not be enough to notice on a modern TV set, if the signal is not
marginal and hovering on the set's AGC threshold in the first place. If
you
take it to its logical conclusion, if you stood the antenna on its 'nose',
it would receive virtually nothing. At some point, horizontal or pointing
slightly *up*, you would be receiving a maximum signal. Anywhere inbetween
must, in theory at least, be less than the potential maximum.

Of course, now we're talking digital TV transmissions, all bets are off on
this ... :-)

Arfa- Hide quoted text -

- Show quoted text -

Digital signals travel through space the same as analog signals at the
same frequency. *The best reception is for the antenna to point
directly at the transmitter. *If there are reflections, then pointing
either upward or downward from the transmitter maight improve
reception. *Digital formatting of the signal may make reflections more
or less of a problem than it was with older analog *signal format.

I see that you're well into all the media and government hype about how good
digital terrestrial TV is then, Bob ...

The (tongue in cheek) point I was making had nothing to do with the format
of the modulating signal, which of course has absolutely nothing to do with
how well or otherwise, the carrier propagates through space. I was actually
referring to less-than-ideal reception circumstances such as those the OP
suggests that he may have, which with an analogue signal, may well give
perfectly acceptable results, but with a digital signal might result in
digital cliff pixellation and freezing. Digital terrestrial TV signals are,
in my experience here in the UK, nothing like as robust, or easily received
in many transmission regions, as the government - whose primary interest
lies in how much money they can make by selling off large chunks of the UHF
TV band to cell phone operators - would have Joe public believe through
their hyped-up and often misleading media campaign directed at the subject
...

Arfa- Hide quoted text -

- Show quoted text -

I agree with everything you said. People tolerate ghosting much
better than digital receivers do. I have two digital convertors that
I play with, but my household tv is on a cable system that a couple of
months ago converted to a special digital transmission on the cable,
not the same as the on-the-air digital system that I use the 2
convertors for..

When we had wet weather, I would lose digital reception on any/all
combinations of the 3 digital cable convertors that my cable company
provided. I complained and got one unit replaced, but still had the
problems. I complained again and they sent a "trained" repairman
out. He immediately said it was my internal house cable distribution
system that was at fault. I replied that unless my house had a bad
roof leak, there was no way that the weather should affect my cable
reception. He finally went out to the telephone pole in my back yard
where the cable came out of the ground and went up the pole to a tap
on their cable. There he discovered, right at the tap, that a
friendly squirrel had chewed through the outside weatherproofing and
that water was getting into the cable. A new drop from the pole to
the house solved the problem, and hopefully when the next squirrel
gets hungry I won't have such a problem getting things fixed.

I did tv repair work in the 1950's to put myself through college and
worked on color tv right after the FCC dropped the CBS color wheel in
favor of the RCA system. Almost worked at Hazeltine Labs because they
acquired many of the RCA color tv patents, but Bell Labs offered to
pay for me to get my Master's degree and so I ended up at Bell Labs.
Was there for 44 years and loved every minute of it. Ended up in EMC
work which was a great adventure as no two days were ever the same.

On Dec 1, 7:30*pm, "Arfa Daily" wrote:
"hr(bob) " wrote in message

...
On Dec 1, 3:42 am, "Arfa Daily" wrote:





"mm" wrote in message

.. .

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

That's an interesting question. I guess to some extent, it depends on the
frequency involved, and how close you are to the transmitter. I feel that
the potential losses are likely to be far worse at UHF than VHF. An
example
that comes to mind is my local ATV repeater. It is sited on a hill, and I
clearly remember some of us helping out a new licensee, who was located
within line of sight of the transmitter mast, about 3/4 mile away, and at
the bottom of the hill. He could barely pick up a signal from it, and
could
not access it with his own 2W transmitter at all. This was at 23cms
(1.2GHz)
so a little above the top of the UHF band. We did some field strength
checks, and found that there was quite a distinct 'shadow' around the
transmitter site, out to a distance of around a mile. The repeater's
antenna
is a slotted waveguide.

The first thing that we did was to re-site his antenna pair onto a taller
mast, which produced a significant improvement to his situation, but was
still not good, considering how close he was to the repeater. The final
thing that we did was to tilt his antennas up at a similar angle to the
hill
itself, and this brought about the improvement to solid P5 copy and
repeater
access, that we had been expecting. I believe I have read that it is
common
to find this shadowing effect around high power TV transmitter masts, and
that it can extend out to several miles in some instances. Michael T could
probably comment better on this as he was involved in the industry.

So, I suppose that on paper, the answer has to be that there will be an
effect on received signal strength with the antenna tilted down, but it
will
probably not be enough to notice on a modern TV set, if the signal is not
marginal and hovering on the set's AGC threshold in the first place. If
you
take it to its logical conclusion, if you stood the antenna on its 'nose',
it would receive virtually nothing. At some point, horizontal or pointing
slightly *up*, you would be receiving a maximum signal. Anywhere inbetween
must, in theory at least, be less than the potential maximum.

Of course, now we're talking digital TV transmissions, all bets are off on
this ... :-)

Arfa- Hide quoted text -

- Show quoted text -

Digital signals travel through space the same as analog signals at the
same frequency. *The best reception is for the antenna to point
directly at the transmitter. *If there are reflections, then pointing
either upward or downward from the transmitter maight improve
reception. *Digital formatting of the signal may make reflections more
or less of a problem than it was with older analog *signal format.

I see that you're well into all the media and government hype about how good
digital terrestrial TV is then, Bob ...

The (tongue in cheek) point I was making had nothing to do with the format
of the modulating signal, which of course has absolutely nothing to do with
how well or otherwise, the carrier propagates through space. I was actually
referring to less-than-ideal reception circumstances such as those the OP
suggests that he may have, which with an analogue signal, may well give
perfectly acceptable results, but with a digital signal might result in
digital cliff pixellation and freezing. Digital terrestrial TV signals are,
in my experience here in the UK, nothing like as robust, or easily received
in many transmission regions, as the government - whose primary interest
lies in how much money they can make by selling off large chunks of the UHF
TV band to cell phone operators - would have Joe public believe through
their hyped-up and often misleading media campaign directed at the subject
...

Arfa- Hide quoted text -

- Show quoted text -

I agree with everything you said. People tolerate ghosting much
better than digital receivers do. I have two digital convertors that
I play with, but my household tv is on a cable system that a couple of
months ago converted to a special digital transmission on the cable,
not the same as the on-the-air digital system that I use the 2
convertors for..

When we had wet weather, I would lose digital reception on any/all
combinations of the 3 digital cable convertors that my cable company
provided. I complained and got one unit replaced, but still had the
problems. I complained again and they sent a "trained" repairman
out. He immediately said it was my internal house cable distribution
system that was at fault. I replied that unless my house had a bad
roof leak, there was no way that the weather should affect my cable
reception. He finally went out to the telephone pole in my back yard
where the cable came out of the ground and went up the pole to a tap
on their cable. There he discovered, right at the tap, that a
friendly squirrel had chewed through the outside weatherproofing and
that water was getting into the cable. A new drop from the pole to
the house solved the problem, and hopefully when the next squirrel
gets hungry I won't have such a problem getting things fixed.

I did tv repair work in the 1950's to put myself through college and
worked on color tv right after the FCC dropped the CBS color wheel in
favor of the RCA system. Almost worked at Hazeltine Labs because they
acquired many of the RCA color tv patents, but Bell Labs offered to
pay for me to get my Master's degree and so I ended up at Bell Labs.
Was there for 44 years and loved every minute of it. Ended up in EMC
work which was a great adventure as no two days were ever the same.

On Nov 30, 11:46*pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. *Does the angle
of the axis matter that much if the individual elements are all
horizontal? *

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. * All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

BTW, as to loss of signal in an attic,http://www.dennysantennaservice.com/...tallation.html
says: "A plywood roof covered by a single layer of asphalt shingles is
best.", (that is, other roofs are worse) and that's just what I have.
I'm sure it would still work better on the roof, but if I lose one or
two stations, I can accept that.

You don't want or need a 13 ft beastly antenna that can get channels
2-6. This little guy will be much easier to handle in the attic
(though it's better outside) and has reasonable gain. Don't jet
fighters release 'chaff' to screw up the enemy? Seems a lot like nails
suspended in sheets of plywood. That's one reason to be outside of the
'chaff'.

http://www.winegard.com/kbase/upload/HD7694P.pdf

BTW there are no channels 51 any more.

G²

Arfa Daily Inscribed thus:
I was actually referring to less-than-ideal reception
circumstances such as those the OP suggests that he may have, which
with an analogue signal, may well give perfectly acceptable results,
but with a digital signal might result in digital cliff pixellation
and freezing. Digital terrestrial TV signals are, in my experience
here in the UK, nothing like as robust, or easily received in many
transmission regions, as the government - whose primary interest lies
in how much money they can make by selling off large chunks of the UHF
TV band to cell phone operators - would have Joe public believe
through their hyped-up and often misleading media campaign directed at
the subject ...

Arfa

Well Said !
Yet another make the people pay Government scheme, among other things.

--
Best Regards:
Baron.

On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46*pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?

I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

mm wrote:
On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46 pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.
Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?

I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

High gain means "narrow bundle" , so a high gain antenna needs
careful aiming.

On Wed, 02 Dec 2009 20:26:45 +0100, Sjouke Burry
wrote:

mm wrote:
On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46 pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.
Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?

I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

High gain means "narrow bundle" , so a high gain antenna needs
careful aiming.

So what aobut people on mountains and in valleys, where the
transmitter is lower or higher than they are. Should their antennas
be tipped down or up to aim at the transimitting antenna?

I never hear anyone recommend that, and afaicr (and I don't spend much
time near mountains, but some), every outdoor antenna I've ever seen
has been horizontal.

mm wrote:
On Wed, 02 Dec 2009 20:26:45 +0100, Sjouke Burry
wrote:

mm wrote:
On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46 pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.
Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?
I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

High gain means "narrow bundle" , so a high gain antenna needs
careful aiming.

So what aobut people on mountains and in valleys, where the
transmitter is lower or higher than they are. Should their antennas
be tipped down or up to aim at the transimitting antenna?

I never hear anyone recommend that, and afaicr (and I don't spend much
time near mountains, but some), every outdoor antenna I've ever seen
has been horizontal.
It turns a little bit into nit picking, but Yes try to aim
as accurately as possible at the transmitter, especially with
multi-element antennas.
And keep in mind,that an antenna cannot look through a big hill
or a mountain. And only with some difficulty through your house/roof
or that of the neighbour.
For the hill/mountain, you might need a repeater on that hill/mountain top.
Or try to find a reliable reflection around those obstacles.
In my country the digital tv is polarized vertically, so although we
can use the same old antennas, they have to be turned on their sides,
and vertical aim is even more important.

On Wed, 2 Dec 2009 01:44:24 -0800 (PST), wrote:

On Nov 30, 11:46*pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. *Does the angle
of the axis matter that much if the individual elements are all
horizontal? *

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. * All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

BTW, as to loss of signal in an attic,http://www.dennysantennaservice.com/...tallation.html
says: "A plywood roof covered by a single layer of asphalt shingles is
best.", (that is, other roofs are worse) and that's just what I have.
I'm sure it would still work better on the roof, but if I lose one or
two stations, I can accept that.

You don't want or need a 13 ft beastly antenna that can get channels
2-6.

I thought this one didn't get 2-6, but I should go check again.

This little guy will be much easier to handle in the attic
(though it's better outside) and has reasonable gain. Don't jet
fighters release 'chaff' to screw up the enemy? Seems a lot like nails
suspended in sheets of plywood. That's one reason to be outside of the
'chaff'.

Good point. Not only that, the roofer used nails that are a lot
longer for the second roof than they had used for the first roof. And
my hair isn't as thick as it used to be if that matters, but I'm more
afraid I'm going to jab my head then I used to be.

http://www.winegard.com/kbase/upload/HD7694P.pdf

BTW there are no channels 51 any more.

Thanks a lot.

G²

On Wed, 02 Dec 2009 23:46:06 +0100, Sjouke Burry
wrote:

mm wrote:
On Wed, 02 Dec 2009 20:26:45 +0100, Sjouke Burry
wrote:

mm wrote:
On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46 pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.
Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?
I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

High gain means "narrow bundle" , so a high gain antenna needs
careful aiming.

So what aobut people on mountains and in valleys, where the
transmitter is lower or higher than they are. Should their antennas
be tipped down or up to aim at the transimitting antenna?

I never hear anyone recommend that, and afaicr (and I don't spend much
time near mountains, but some), every outdoor antenna I've ever seen
has been horizontal.
It turns a little bit into nit picking, but Yes try to aim
as accurately as possible at the transmitter, especially with
multi-element antennas.
And keep in mind,that an antenna cannot look through a big hill
or a mountain. And only with some difficulty through your house/roof
or that of the neighbour.
For the hill/mountain, you might need a repeater on that hill/mountain top.
Or try to find a reliable reflection around those obstacles.
In my country the digital tv is polarized vertically, so although we
can use the same old antennas, they have to be turned on their sides,
and vertical aim is even more important.

Very interesting. Really

What about places where there is line of sight between the
transmitting antenna and the home antenna, but the home is a lot lower
or higher than than the T-antenna. Does the home antenna need to be
tipped up to point to a transmitting antenna that's higher? It sounds
like that follows from what was said ealier in this thread, but I've
never seeen it done or recommended.

mm wrote:
On Wed, 02 Dec 2009 23:46:06 +0100, Sjouke Burry
wrote:

mm wrote:
On Wed, 02 Dec 2009 20:26:45 +0100, Sjouke Burry
wrote:

mm wrote:
On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46 pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.
Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?
I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

High gain means "narrow bundle" , so a high gain antenna needs
careful aiming.
So what aobut people on mountains and in valleys, where the
transmitter is lower or higher than they are. Should their antennas
be tipped down or up to aim at the transimitting antenna?

I never hear anyone recommend that, and afaicr (and I don't spend much
time near mountains, but some), every outdoor antenna I've ever seen
has been horizontal.
It turns a little bit into nit picking, but Yes try to aim
as accurately as possible at the transmitter, especially with
multi-element antennas.
And keep in mind,that an antenna cannot look through a big hill
or a mountain. And only with some difficulty through your house/roof
or that of the neighbour.
For the hill/mountain, you might need a repeater on that hill/mountain top.
Or try to find a reliable reflection around those obstacles.
In my country the digital tv is polarized vertically, so although we
can use the same old antennas, they have to be turned on their sides,
and vertical aim is even more important.

Very interesting. Really

What about places where there is line of sight between the
transmitting antenna and the home antenna, but the home is a lot lower
or higher than than the T-antenna. Does the home antenna need to be
tipped up to point to a transmitting antenna that's higher? It sounds
like that follows from what was said ealier in this thread, but I've
never seeen it done or recommended.
Well, you aim carefully at the horizon, and hope that enough radiation
is following the earth surface.
Some bending down always occurs, and hopefully for you it is enough.

What about places where there is line of sight between the
transmitting antenna and the home antenna, but the home is a lot lower
or higher than than the T-antenna. Does the home antenna need to be
tipped up to point to a transmitting antenna that's higher? It sounds
like that follows from what was said ealier in this thread, but I've
never seeen it done or recommended.

You may get a slight increase in signal by uptilting the receive
antenna.

However, this is hard to predict, and usually not a terribly
significant factor, for two reasons:

(1) The amount of up-tilt you would need is not likely, in most cases,
to be more than a few degrees. It's probably less than the
"half-power vertical beam-width" of a typical TV antenna... likely
quite a lot less.

If, for example, the transmitting antenna is only 2 or 3 degrees
above the horizon, and the receiving antenna's vertical pattern
has a half-power beamwidth of 10 degrees or more (which would be
the case for all but the longest, highest-gain TV antennas), then
the amount of power you'd be giving up by not uptilting the
antenna is negligible.

(2) The signal path from the transmitter to your antenna is
complicated by reflections off of the ground, nearby buildings,
hills, and so forth. You might actually find a higher-quality
signal by pointing your antenna slightly away from the transmitter,
if by doing so you picked up a particularly strong reflection, or
_avoided_ picking up a side reflection which was causing multipath
distortion.

The cases in which an antenna needs to be pointed very exactly (both
horizontally and vertically), are those in which it has a very high
gain and thus a narrow beamwidth. How often will you be far enough
away from a transmitter that you need an antenna with this much gain,
*and* be so far below it that its position is a significant distance
above the horizon and would need to tilt it up by more than a few
degrees?

I don't think this combination of circumstances is at all common. If
it's close enough and high enough that it's far above the horizon,
then you're almost certainly able to use a low-gain antenna with a
very broad vertical pattern, and will get plenty of signal.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Tue, 01 Dec 2009 02:46:53 -0500, mm
wrote:

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

A small amount of tilt won't make a significant difference. Those that
suggest tilting the antenna will increase the gain are misguided. The
antenna can take advantage of ground reflection up to a theoretical
6db of gain. This gain is seldom reached but the in phase reflected e
field that causes this gain is best achieved when the antenna is
horizontal.

In article , mm wrote:
On Wed, 02 Dec 2009 20:26:45 +0100, Sjouke Burry
wrote:

mm wrote:
On Tue, 1 Dec 2009 14:35:23 -0800 (PST), whit3rd
wrote:

On Nov 30, 11:46 pm, mm wrote:
One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.
Yes, it matters; the main part of that long antenna is 'director'
elements, which create a kind of shadow on the active
dipole. The rays get past if you aren't roughly lined up with
the line-of-sight to the transmitter.

Also, such a long antenna has high 'gain' which means it
MUST be aimed carefully; how can you possibly adjust it
if it's bumping into the roof?

I may be confused about what "gain" is. Why would a high gain antenna
have to be aimed carefully? If it has high gain, it seems like it
would have some gain to spare if it were badly aimed.

If it had low gain, it seems like it would have to be aimed precisely.

High gain means "narrow bundle" , so a high gain antenna needs
careful aiming.

So what aobut people on mountains and in valleys, where the
transmitter is lower or higher than they are. Should their antennas
be tipped down or up to aim at the transimitting antenna?

I never hear anyone recommend that, and afaicr (and I don't spend much
time near mountains, but some), every outdoor antenna I've ever seen
has been horizontal.

In any situation, if you have done this before, sometimes
it helps and sometimes it doesn't. You are also likely to see
similar results rotating the antenna from horizontal. The transmitted
waves change the plane as it moves over obsticles, so one station
may work better tilted 10 degrees, but it may make the other station worse.

Gain is made by narrowing the beamwidth and providing more front to back ratio.
A NASA 85 foot dish has about a 1 degree beamwidth at 2.3 gHz.

greg

On Thu, 03 Dec 2009 04:44:51 -0500, wrote:

On Tue, 01 Dec 2009 02:46:53 -0500, mm
wrote:

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

A small amount of tilt won't make a significant difference. Those that
suggest tilting the antenna will increase the gain are misguided. The
antenna can take advantage of ground reflection up to a theoretical
6db of gain. This gain is seldom reached but the in phase reflected e
field that causes this gain is best achieved when the antenna is
horizontal.

Thanks, and thanks to everyone. in this thread, and if possible,
for any place I haven't thanked people.

wrote in message
...
On Tue, 01 Dec 2009 02:46:53 -0500, mm
wrote:

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

A small amount of tilt won't make a significant difference. Those that
suggest tilting the antenna will increase the gain are misguided. The
antenna can take advantage of ground reflection up to a theoretical
6db of gain. This gain is seldom reached but the in phase reflected e
field that causes this gain is best achieved when the antenna is
horizontal.

It depends on how close in you are to the transmitter mast. Look at cell
phone sites beside roads. The flat panel antennas on those masts are angled
down significantly to avoid shadowing around the mast. As I said earlier in
this thread, I experienced a real life example of the effect of antenna tilt
at the bottom of a hill, close in to a transmitter that was on the top of
the hill. Nothing will affect the actual 'gain' of the antenna when it's
mounted in reasonably free space. However, tilting, under *some*
circumstances, may improve its ability to interact with the radiated field
from the transmitter, resulting in an increase in the received signal level,
relative to a no-tilt situation.

Arfa

On Fri, 4 Dec 2009 02:39:00 -0000, "Arfa Daily"
wrote:


wrote in message
.. .
On Tue, 01 Dec 2009 02:46:53 -0500, mm
wrote:

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

A small amount of tilt won't make a significant difference. Those that
suggest tilting the antenna will increase the gain are misguided. The
antenna can take advantage of ground reflection up to a theoretical
6db of gain. This gain is seldom reached but the in phase reflected e
field that causes this gain is best achieved when the antenna is
horizontal.

It depends on how close in you are to the transmitter mast. Look at cell
phone sites beside roads. The flat panel antennas on those masts are angled
down significantly to avoid shadowing around the mast. As I said earlier in
this thread, I experienced a real life example of the effect of antenna tilt
at the bottom of a hill, close in to a transmitter that was on the top of
the hill. Nothing will affect the actual 'gain' of the antenna when it's
mounted in reasonably free space. However, tilting, under *some*
circumstances, may improve its ability to interact with the radiated field
from the transmitter, resulting in an increase in the received signal level,
relative to a no-tilt situation.

Arfa

If tilting the antenna made a difference then the receiver is very
close to the transmitter.

If the proximity was that close you could use rabbit ears.

wrote in message
...
On Fri, 4 Dec 2009 02:39:00 -0000, "Arfa Daily"
wrote:


wrote in message
. ..
On Tue, 01 Dec 2009 02:46:53 -0500, mm
wrote:

One more antenna question: Antenna pitch?

That is, my attic has a pitched roof and the antenna for channels 7 to
60 that I'm thinking of now is almost 13 feet long.

It would fit more easily in the attic if I pointed it down a little
bit just like the roof pitches down from the center. Does the angle
of the axis matter that much if the individual elements are all
horizontal?

After all, if the tranmitter is higher than the antenna, it's as if
even a horizontal antenna is pointed down, from the pov of the
transmitter.

I've been reading but nothing has addressed this. All outdoor
antennas are of course horizontal, and I don't get to see people's
indoor antennas.

A small amount of tilt won't make a significant difference. Those that
suggest tilting the antenna will increase the gain are misguided. The
antenna can take advantage of ground reflection up to a theoretical
6db of gain. This gain is seldom reached but the in phase reflected e
field that causes this gain is best achieved when the antenna is
horizontal.

It depends on how close in you are to the transmitter mast. Look at cell
phone sites beside roads. The flat panel antennas on those masts are
angled
down significantly to avoid shadowing around the mast. As I said earlier
in
this thread, I experienced a real life example of the effect of antenna
tilt
at the bottom of a hill, close in to a transmitter that was on the top of
the hill. Nothing will affect the actual 'gain' of the antenna when it's
mounted in reasonably free space. However, tilting, under *some*
circumstances, may improve its ability to interact with the radiated field
from the transmitter, resulting in an increase in the received signal
level,
relative to a no-tilt situation.

Arfa

If tilting the antenna made a difference then the receiver is very
close to the transmitter.

If the proximity was that close you could use rabbit ears.

Yes, I'll go along with that. In the case that I cited, the receiver *was*
close to the transmitter, which was an amateur TV repeater with a 10 watt
input (less cable losses) to the antenna. All of this discussion is pretty
academic anyway, and I was just indicating that as well as on paper, in the
real world, antenna tilt *can*, under some unusual circumstances such as
this, have a significant effect, the implication being that if you extend
that out across the board, it *is* a real effect, allbeit of no significance
in the vast majority of cases.

I think it is highly unlikely that it would be a noticeable effect for the
OP, but may be visible on a signal strength meter, given that he is
proposing using a very long multi-element antenna (at VHF I think ?) - which
I guess he must be thinking of using because of potentially marginal
reception conditions - and which will have a comparitively narrow beamwidth
in both the horizontal, and vertical planes.

Arfa