hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?

Le Sat, 05 Aug 2006 11:38:23 GMT,
ml a écrit :

hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?

It MUST be a direct view from the antenna to the sat. Otherwise is it
just to forget it. With analog reception, the antenna can work very
well through a glass window, or while directing the antenna on a
reflexion (at least if you can afford a high end tuner in this last case),
by but with digital reception, even a tiny glass will cause a
lot of trouble (some channels will just disappear), because the digital technique use phase multiplexing
and the phase of the signal will change in a non linear fashion through
the glass or on a reflexion.

Dominique

"ml" wrote in message
...
hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?

Hi ml

Do you intend to work AMSAT polar orbiting satellites?
Is your antenna stearable?
What frequency?

Jerry

Are you asking about amateur satellite operation or TV reception via
satellites? Although Dominique’s explanation of digital satellite
signals passing through glass may be explained on paper, it has no merit
in actual use. Some glass has attenuation at C/Ku frequencies but this
purely shows up as signal reduction with associated loss of C/N, BER,
etc in digital systems. Analog and digital satellite reception are
affected the same.
Bob


Dominique Michel wrote:
Le Sat, 05 Aug 2006 11:38:23 GMT,
ml a écrit :

hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?

It MUST be a direct view from the antenna to the sat. Otherwise is it
just to forget it. With analog reception, the antenna can work very
well through a glass window, or while directing the antenna on a
reflexion (at least if you can afford a high end tuner in this last case),
by but with digital reception, even a tiny glass will cause a
lot of trouble (some channels will just disappear), because the digital technique use phase multiplexing
and the phase of the signal will change in a non linear fashion through
the glass or on a reflexion.

Dominique

Le Sat, 05 Aug 2006 15:33:07 GMT,
Bob a écrit :

Are you asking about amateur satellite operation or TV reception via
satellites? Although Dominique’s explanation of digital satellite
signals passing through glass may be explained on paper, it has no merit
in actual use. Some glass has attenuation at C/Ku frequencies but this
purely shows up as signal reduction with associated loss of C/N, BER,
etc in digital systems. Analog and digital satellite reception are
affected the same.
Bob


What I say here is based on personal experience. And it is for TV reception that use phase multiplexing in order to send many different channels on the same frequency. The signal going through a glass is affected in a way that do impossible to receive some channels. A bigger parabol will change nothing, it is just to remove the glass to get all the channels.

You get exactly the same effect if the shape of the parabol is not
perfect (as it can append after a hazard under transportation), it will
work just fine for analog reception but with a digital tuner, some
channels will work when others will not. It is just to change the
parabol to get all the channels. Sometime, the defect with the shape of
the parabol is so little as you see nothing with the eyes, but you
change it against another one from the same model and it just work. I
installed hundreds of parabol antenna, and it was never a problem with
a wholesaler or a manufacturer to change a defective parabol, they know this problem very well.

Dominique


Dominique Michel wrote:
Le Sat, 05 Aug 2006 11:38:23 GMT,
ml a écrit :

hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?

It MUST be a direct view from the antenna to the sat. Otherwise is it
just to forget it. With analog reception, the antenna can work very
well through a glass window, or while directing the antenna on a
reflexion (at least if you can afford a high end tuner in this last case),
by but with digital reception, even a tiny glass will cause a
lot of trouble (some channels will just disappear), because the digital technique use phase multiplexing
and the phase of the signal will change in a non linear fashion through
the glass or on a reflexion.

Dominique

Dominique,
I am also speaking from personal and professional experience with Ku
QPSK MCPC systems. Signal loss through the glass in dB correlates with
the same decrease in Eb/No in digital systems. I am curious what your
location is and what systems you have worked with.
Bob

Dominique Michel wrote:
Le Sat, 05 Aug 2006 15:33:07 GMT,
Bob a écrit :

Are you asking about amateur satellite operation or TV reception via
satellites? Although Dominique’s explanation of digital satellite
signals passing through glass may be explained on paper, it has no merit
in actual use. Some glass has attenuation at C/Ku frequencies but this
purely shows up as signal reduction with associated loss of C/N, BER,
etc in digital systems. Analog and digital satellite reception are
affected the same.
Bob


What I say here is based on personal experience. And it is for TV reception that use phase multiplexing in order to send many different channels on the same frequency. The signal going through a glass is affected in a way that do impossible to receive some channels. A bigger parabol will change nothing, it is just to remove the glass to get all the channels.

You get exactly the same effect if the shape of the parabol is not
perfect (as it can append after a hazard under transportation), it will
work just fine for analog reception but with a digital tuner, some
channels will work when others will not. It is just to change the
parabol to get all the channels. Sometime, the defect with the shape of
the parabol is so little as you see nothing with the eyes, but you
change it against another one from the same model and it just work. I
installed hundreds of parabol antenna, and it was never a problem with
a wholesaler or a manufacturer to change a defective parabol, they know this problem very well.

Dominique

Dominique Michel wrote:
Le Sat, 05 Aug 2006 11:38:23 GMT,
ml a écrit :

hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?
It MUST be a direct view from the antenna to the sat. Otherwise is it
just to forget it. With analog reception, the antenna can work very
well through a glass window, or while directing the antenna on a
reflexion (at least if you can afford a high end tuner in this last case),
by but with digital reception, even a tiny glass will cause a
lot of trouble (some channels will just disappear), because the digital technique use phase multiplexing
and the phase of the signal will change in a non linear fashion through
the glass or on a reflexion.

Dominique

Le Sat, 05 Aug 2006 21:20:00 GMT,
Bob a écrit :

Dominique,
I am also speaking from personal and professional experience with Ku
QPSK MCPC systems. Signal loss through the glass in dB correlates with
the same decrease in Eb/No in digital systems. I am curious what your
location is and what systems you have worked with.
Bob


I am in Switzerland now, but the location at that time (2 years ago) was near Malmö in Sweden.
The kind of system I was working with was mostly consumer grade electronics, 50 % Nokia complete sat system, and 50 % other brands as philips or samsung. All digital. A few years before that it was mostly analog systems, but the transition between analog and digital was going very fast.

I have done a few big installations too, but is was mostly mixed analog-digital cable TV here, or analog sat mixed with normal TV antennas.

For the sats, the most wanted was Sirius, Thor, Hotbird and Astra. And it was on ku band too.

For the parabol antenna, my favorite ones was nokia and Wisi. Wisi have a good quality and not only consumer grads products, but also professional material, and they have a technical staff that know the job very well.

Dominique

Dominique Michel wrote:
Le Sat, 05 Aug 2006 15:33:07 GMT,
Bob a écrit :

Are you asking about amateur satellite operation or TV reception via
satellites? Although Dominique’s explanation of digital satellite
signals passing through glass may be explained on paper, it has no merit
in actual use. Some glass has attenuation at C/Ku frequencies but this
purely shows up as signal reduction with associated loss of C/N, BER,
etc in digital systems. Analog and digital satellite reception are
affected the same.
Bob


What I say here is based on personal experience. And it is for TV reception that use phase multiplexing in order to send many different channels on the same frequency. The signal going through a glass is affected in a way that do impossible to receive some channels. A bigger parabol will change nothing, it is just to remove the glass to get all the channels.

You get exactly the same effect if the shape of the parabol is not
perfect (as it can append after a hazard under transportation), it will
work just fine for analog reception but with a digital tuner, some
channels will work when others will not. It is just to change the
parabol to get all the channels. Sometime, the defect with the shape of
the parabol is so little as you see nothing with the eyes, but you
change it against another one from the same model and it just work. I
installed hundreds of parabol antenna, and it was never a problem with
a wholesaler or a manufacturer to change a defective parabol, they know this problem very well.

Dominique

Dominique Michel wrote:
Le Sat, 05 Aug 2006 11:38:23 GMT,
ml a écrit :

hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be blind

question:

so is their a particular compas headding that is best to loose?
It MUST be a direct view from the antenna to the sat. Otherwise is it
just to forget it. With analog reception, the antenna can work very
well through a glass window, or while directing the antenna on a
reflexion (at least if you can afford a high end tuner in this last case),
by but with digital reception, even a tiny glass will cause a
lot of trouble (some channels will just disappear), because the digital technique use phase multiplexing
and the phase of the signal will change in a non linear fashion through
the glass or on a reflexion.

Dominique

Someone asked if i was referring to amateur sat's, yes i was referring
to the amateur sats exclusivly

my question remains, so if i must loose one compass direction what
should it be?

thanks


In article 20060806005142.7b4d9f3f@localhost,
Dominique Michel wrote:

Le Sat, 05 Aug 2006 21:20:00 GMT,
Bob a écrit :

Dominique,
I am also speaking from personal and professional experience with Ku
QPSK MCPC systems. Signal loss through the glass in dB correlates with
the same decrease in Eb/No in digital systems. I am curious what your
location is and what systems you have worked with.
Bob


I am in Switzerland now, but the location at that time (2 years ago) was near
Malmö in Sweden.
The kind of system I was working with was mostly consumer grade electronics,
50 % Nokia complete sat system, and 50 % other brands as philips or samsung.
All digital. A few years before that it was mostly analog systems, but the
transition between analog and digital was going very fast.

I have done a few big installations too, but is was mostly mixed
analog-digital cable TV here, or analog sat mixed with normal TV antennas.

For the sats, the most wanted was Sirius, Thor, Hotbird and Astra. And it was
on ku band too.

For the parabol antenna, my favorite ones was nokia and Wisi. Wisi have a
good quality and not only consumer grads products, but also professional
material, and they have a technical staff that know the job very well.

Dominique

Dominique Michel wrote:
Le Sat, 05 Aug 2006 15:33:07 GMT,
Bob a écrit :

Are you asking about amateur satellite operation or TV reception via
satellites? Although Dominique’s explanation of digital satellite
signals passing through glass may be explained on paper, it has no merit
in actual use. Some glass has attenuation at C/Ku frequencies but this
purely shows up as signal reduction with associated loss of C/N, BER,
etc in digital systems. Analog and digital satellite reception are
affected the same.
Bob


What I say here is based on personal experience. And it is for TV
reception that use phase multiplexing in order to send many different
channels on the same frequency. The signal going through a glass is
affected in a way that do impossible to receive some channels. A bigger
parabol will change nothing, it is just to remove the glass to get all
the channels.

You get exactly the same effect if the shape of the parabol is not
perfect (as it can append after a hazard under transportation), it will
work just fine for analog reception but with a digital tuner, some
channels will work when others will not. It is just to change the
parabol to get all the channels. Sometime, the defect with the shape of
the parabol is so little as you see nothing with the eyes, but you
change it against another one from the same model and it just work. I
installed hundreds of parabol antenna, and it was never a problem with
a wholesaler or a manufacturer to change a defective parabol, they know
this problem very well.

Dominique

Dominique Michel wrote:
Le Sat, 05 Aug 2006 11:38:23 GMT,
ml a écrit :

hi

thinking about getting into sat's, and have a newbie question

i may only be permitted to put up my antennas on a part of the roof
that
would be blocked by a structure(elevator room)

so in 1 compass direction or so to almost straight up i would be
blind

question:

so is their a particular compas headding that is best to loose?
It MUST be a direct view from the antenna to the sat. Otherwise is it
just to forget it. With analog reception, the antenna can work very
well through a glass window, or while directing the antenna on a
reflexion (at least if you can afford a high end tuner in this last
case),
by but with digital reception, even a tiny glass will cause a
lot of trouble (some channels will just disappear), because the digital
technique use phase multiplexing
and the phase of the signal will change in a non linear fashion through
the glass or on a reflexion.

Dominique

"ml" wrote in message
...
Someone asked if i was referring to amateur sat's, yes i was referring
to the amateur sats exclusivly

my question remains, so if i must loose one compass direction what
should it be?

thanks

Hi ml

The least valuable compass direction for you is either East or West, if
the satellites are Polar Orbiting Satellites.

Jerry

SNIP SNIP

ml wrote:
Someone asked if i was referring to amateur sat's, yes i was referring
to the amateur sats exclusivly

my question remains, so if i must loose one compass direction what
should it be?

thanks

In the limited amateur satellite action I've had I've needed all four
compass directions but early on got away with only having an azimuth
rotator, fixing elevation at about 50 degrees above the horizon. I
didn't get the low el passes well or at all until I had an elevation
rotor but it worked quite well most other times.

If you're thinking you'd only use an elevation rotor so you could track
horizon to horizon I'd set it up on a north-south line, not only for the
polar orbit sats but also it probably wouldn't be so bad for the others.
If you're using yagis I'd put the elements perpendicular to the
direction of tracking, parallel to the axis of rotation due to the
beamwidth of a yagi in that direction.

Personally I'd start with azimuth only if I couldn't do both axis
simultaneously.

Good luck,
Galen, W8LNA