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sat ant question
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? |
sat ant question
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 |
sat ant question
"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 |
sat ant question
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 |
sat ant question
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 |
sat ant question
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 |
sat ant question
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 |
sat ant question
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 |
sat ant question
"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 |
sat ant question
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 |
sat ant question
In article 6qHBg.9394$qw5.7976@trnddc06,
"Jerry Martes" wrote: "ml" wrote in message ... Someone asked if i was referring to amateur sat's, yes i was referring to the amateur sats exclusivly my question remains, so if i must loose one compass direction what should it be? thanks Hi ml The least valuable compass direction for you is either East or West, if the satellites are Polar Orbiting Satellites. Jerry SNIP SNIP thanks very much, being a real newbie i have to ask one quick one so are 'most' of the sat's polar orbiting? thanks all again i hate to loose a 'compas' heading but i can't move the wall or go over it do to coop rules so just tring to figure out how many birds i'll loose to see if it's worthwile gwatts thanks for the help too, but i sure would have 2 rotors all i would 'loose' is a single compas heading |
sat ant question
"ml" wrote in message ... In article 6qHBg.9394$qw5.7976@trnddc06, "Jerry Martes" wrote: "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 thanks very much, being a real newbie i have to ask one quick one so are 'most' of the sat's polar orbiting? Hi ml I thought all the amateur satellites were polar orbiting. But, I really am not sure. Perhaps you could Google then download Orbitron. That site will show you all the satellites and their location as well as their path prediction. I'd strongly recomend your contacting the AMSAT group. There are some very well informed guys there. I mentioned that you might be willing to let your building shadow either East or West only because there will statistically fewer times when satelites will be passing there. the majority of the passes will be within a sector to your North-South. You will have to consider what kind of communication you want. That is, if you are interested in communicating with someone in Europe, and you are located in Florida, you sure wouldnt want to block out satellites to your East. But, if you are in Maine, you may have little interest in communicating with stations to your North. Jerry |
sat ant question
In article rZRBg.8608$l95.2822@trnddc08,
"Jerry Martes" wrote: "ml" wrote in message ... In article 6qHBg.9394$qw5.7976@trnddc06, "Jerry Martes" wrote: "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 thanks very much, being a real newbie i have to ask one quick one so are 'most' of the sat's polar orbiting? Hi ml I thought all the amateur satellites were polar orbiting. But, I really am not sure. Perhaps you could Google then download Orbitron. That site will show you all the satellites and their location as well as their path prediction. I'd strongly recomend your contacting the AMSAT group. There are some very well informed guys there. I mentioned that you might be willing to let your building shadow either East or West only because there will statistically fewer times when satelites will be passing there. the majority of the passes will be within a sector to your North-South. You will have to consider what kind of communication you want. That is, if you are interested in communicating with someone in Europe, and you are located in Florida, you sure wouldnt want to block out satellites to your East. But, if you are in Maine, you may have little interest in communicating with stations to your North. Jerry hmm the amsat idea was pretty good i guess i have a bunch of simple questoints they could answer in a few seconds, apreciate again everybodys help here :) i suddenly got bit by the sat bug so kinda raw |
sat ant question
ml wrote in :
In article rZRBg.8608$l95.2822@trnddc08, "Jerry Martes" wrote: "ml" wrote in message ... In article 6qHBg.9394$qw5.7976@trnddc06, "Jerry Martes" wrote: "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 thanks very much, being a real newbie i have to ask one quick one so are 'most' of the sat's polar orbiting? Hi ml I thought all the amateur satellites were polar orbiting. But, I really am not sure. Perhaps you could Google then download Orbitron. That site will show you all the satellites and their location as well as their path prediction. I'd strongly recomend your contacting the AMSAT group. There are some very well informed guys there. I mentioned that you might be willing to let your building shadow either East or West only because there will statistically fewer times when satelites will be passing there. the majority of the passes will be within a sector to your North-South. You will have to consider what kind of communication you want. That is, if you are interested in communicating with someone in Europe, and you are located in Florida, you sure wouldnt want to block out satellites to your East. But, if you are in Maine, you may have little interest in communicating with stations to your North. Jerry hmm the amsat idea was pretty good i guess i have a bunch of simple questoints they could answer in a few seconds, apreciate again everybodys help here :) i suddenly got bit by the sat bug so kinda raw See www.amsat.org I'm a life member. The best book to get for beginners is the ARRL's 'Satellite Experimenters Handbook.' Satellite antennas don't need to be high. Mine are at 20 feet, just high enough to peek over the ridge line of the house when the satellite is on the horizon. As far as the compass direction question goes, what is your latitude, and just how much blockage will you have in the direction you loose? Satellites could be anywhere in the sky relative to your location if their inclination is greater than your latitude. 73 & hope to hear you on the birds soon. SC |
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