How can sat radio work almost....

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igator99

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Feb 16, 2006
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any place yet you have to be right on target to get tv. I was wondering about the delivery of satellite radio versus TV. I would imagine sat radio is some sort of broad beam and is easier to deliver than a tv signal. I can actually get sirius under my carport. Try that with TV.
 
damaged

damaged

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Jun 22, 2005
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"System design: Satellite radio uses the 2.3 GHz S band in North America, and generally shares the 1.4 GHz L band with local Digital Audio Broadcast (DAB) stations elsewhere. It is a type of direct broadcast satellite, and is strong enough that it requires no satellite dish to receive. Curvature of the Earth limits the reach of the signal, but due to the high orbit of the satellites, two or three are usually sufficient to provide coverage for an entire continent.

Local repeaters similar to broadcast translator boosters enable signals to be available even if the view of the satellite is blocked, for example, by skyscrapers in a large town. Major tunnels can also have repeaters. This method also allows local programming to be transmitted such as traffic and weather in most major metropolitan areas, as of March 2004.

Source: http://en.wikipedia.org/wiki/Satellite_radio
 
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igator99

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damaged said:
"System design: Satellite radio uses the 2.3 GHz S band in North America, and generally shares the 1.4 GHz L band with local Digital Audio Broadcast (DAB) stations elsewhere. It is a type of direct broadcast satellite, and is strong enough that it requires no satellite dish to receive. Curvature of the Earth limits the reach of the signal, but due to the high orbit of the satellites, two or three are usually sufficient to provide coverage for an entire continent.

Local repeaters similar to broadcast translator boosters enable signals to be available even if the view of the satellite is blocked, for example, by skyscrapers in a large town. Major tunnels can also have repeaters. This method also allows local programming to be transmitted such as traffic and weather in most major metropolitan areas, as of March 2004.

Source: http://en.wikipedia.org/wiki/Satellite_radio

Thanks for the info I was curious how it worked almost everyplace.
 
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HDTVFanAtic

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May 23, 2005
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Because truth be know, Satellite Radio is BS.

98% of the time you are listening to the local repeater that is ground based.

Driving CrossCountry you might actually be listening to the satellite.
 
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igator99

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HDTVFanAtic said:
Because truth be know, Satellite Radio is BS.

98% of the time you are listening to the local repeater that is ground based.

Driving CrossCountry you might actually be listening to the satellite.

So they have local towers? That would explain a lot to me as the difference between beaming down a TV versus a radio signal. My Sirus cuts out once in a while when I'm driving through a long row of tall trees but that is it. All from a little 2x2 square. It would also explain why when at home I have to move the antenna or what ever you call that little thing around to get a good signal.
 
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PoitNarf

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Oct 17, 2004
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Northern NJ
HDTVFanAtic said:
Because truth be know, Satellite Radio is BS.

98% of the time you are listening to the local repeater that is ground based.

Driving CrossCountry you might actually be listening to the satellite.

Actually I'd say in my case it's closer to 50%. There are plenty of times when I go under an overpass and I lose the Sirius signal for a few seconds. Go try and eliminate the line of sight your antenna has with the sats and see how often you have no signal. I'm sure it's going to be more than the 2% average sat signal loss that you claim.

Ofcourse I'm speaking of my experience with my Sirius tuner. I think XM has more repeaters than Sirius but I could be wrong.

Sirius repeater map: http://www.dogstarradio.com/sirius_map.php
 
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H

HDTVFanAtic

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May 23, 2005
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PoitNarf said:
Actually I'd say in my case it's closer to 50%. There are plenty of times when I go under an overpass and I lose the Sirius signal for a few seconds. Go try and eliminate the line of sight your antenna has with the sats and see how often you have no signal. I'm sure it's going to be more than the 2% average sat signal loss that you claim.

Ofcourse I'm speaking of my experience with my Sirius tuner. I think XM has more repeaters than Sirius but I could be wrong.

Sirius repeater map: http://www.dogstarradio.com/sirius_map.php

Actually, as Sirius satellites are moving constantly and XM are stationary, Sirius is harder to receive continually without the repeaters.
 
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PoitNarf

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Oct 17, 2004
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Northern NJ
HDTVFanAtic said:
Actually, as Sirius satellites are moving constantly and XM are stationary, Sirius is harder to receive continually without the repeaters.

Not from what I've read. From what I've seen Sirius requires less repeaters than XM because their sats aren't over the equator, they are north of it when over the US, with at least 1 of their sats being over the US at any given time. Because of this the Sirius sats are higher up and are less likely to be blocked by trees, buildings, etc. Most of the time when I lose my Sirius signal it is due to something blocking my signal directly overhead me.

From SiriusBackstage.com:

"Actually XM has over 1300 repeaters and Sirius may be up to 200 now. Why more XM repeaters? Because they need them... they are for large urban areas mainly with high rises that its satelilites dont have a clear view of (sort of a shadow effect), XM birds are at about 45degres on the southern horizon and stationary. Sirius 3 birds are at about 65 degrees (almost overhead) and constantly moving in orbit over North America, so they have a better view into those concrete canyons of big cities. As time goes by, I am sure Sirius will be adding more repeaters where needed, but as of now the reason is they dont have to as much as XM does."

From space.com:

"Since geostationary spacecraft are above the equator, terminals on the ground must have a decent view of the southern sky to receive signals from them. This posed a challenge for XM, since listeners in cars often pass by obstacles, such as buildings, foliage or hills, which can block geostationary satellite signals.

XMs solution is a network of repeaters antennas on buildings and other sites that receive satellite signals from an optimally placed antenna and retransmit them. The repeaters are located primarily in built-up areas, where loss of the satellite signal is most likely to occur. ....

Sirius uses a trio of Loral FS1300 satellites in unique elliptical orbits in an effort to avoid the problems posed by geostationary satellites.

The orbits, shaped like figure eights, allow the satellites to appear higher in the sky than XMs, cutting down on the potential for a listener to be out of range of a satellite signal -- and allowing Sirius to have a much smaller number of repeaters."

Care to rethink your stance? :p
 
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myquealer

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Jul 13, 2006
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Sirius satellites are much higher in the sky than XM satellites. This makes Sirius much easier to receive from a car than XM. Because the Sirius satellites are always moving they can be harder to receive at home. With XM you can place your home antenna somewhere that you get a strong satellite signal and leave it. Of course you need a clear view fairly low in the southern sky, like satellite TV. With Sirius you may have a strong signal from the satellites on your home antenna and the signal will fade out because the satellites moved to a place they are blocked.

http://www.DogstarRadio.com/sirius_map.php

The map at DogstarRadio shows the location of all the US and Canadian Sirius repeaters (just over 250). It also shows the current position of the satellites (and where they will be in one hour and two hours). It also has a big yellow 8 on it showing the path of the satellites. You should place your home antenna so it has a clear view, high in the sky in all directions of the 8 north of the equator.

Where I live I rely on the satellite signal 100%. I recently took a vacation which involved 3000 miles of driving. All total I was within range of repeaters for about 30 miles of the trip (in Portland and Salt Lake City). There was only one point the entire trip where I lost the satellite signal long enough to cause a droput and it was only about 1 second long (at the end of a long tunnel near Portland). Unless you live in a big city you are going to be relying mostly on the satellite signal.
 
HCI

HCI

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Jun 19, 2005
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Anyone have a list of XM's repeaters? I sit my antenna beside me on my console so I can switch vehicles and it works fine. Signal is not 100% but I rarely have an outage.
 
damaged

damaged

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Jun 22, 2005
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The Tate said:
Anyone have a list of XM's repeaters? I sit my antenna beside me on my console so I can switch vehicles and it works fine. Signal is not 100% but I rarely have an outage.

You can look here, it may have what you want, this thread is full of maps:

http://www.xm411.com/phpbb/viewtopic.php?t=24016&postdays=0&postorder=asc&start=0

If they don't have a map you want, you can request one in that thread.

This thread may be of interest too:

http://www.xm411.com/phpbb/viewtopic.php?t=616
 
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H

HDTVFanAtic

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May 23, 2005
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My last experience with Sirius with in Richmond, Airport is 12 miles East of downtown and I was driving 10 miles west.

67 signal losses in 22 miles. Thats when I finally gave up and went to terrestial radio. I did check and the repeater in Richmond was down that week.

Believe what you want from the 15 PR firms that the 2 companies employee between the 2 of them to flood the market with propoganda.

Sirius only has 2 satellites North of the Equator at any one time. They fly in a figure 8 pattern.

They are moving and you are moving. It makes it even harder to lock on to a bird.

All one must do is go back 4-5 years and read the troubles Sirius had launching the system as the satellites were so hard to lock on to and you would understand this.

If you are moving - and the satellites are moving -2 moving targets - makes the signal harder to lock on to.

It's much easier to lock onto a signal that is stationary, regardless what the PR firms will have you believe.

Or in very simplistic terms, is it easier for a Quarterback to make a sucessful pass when he is standing still or running and being forced to pass while the receiver is also moving.

PoitNarf said:
"Since geostationary spacecraft are above the equator, terminals on the ground must have a decent view of the southern sky to receive signals from them. This posed a challenge for XM, since listeners in cars often pass by obstacles, such as buildings, foliage or hills, which can block geostationary satellite signals.

XMs solution is a network of repeaters antennas on buildings and other sites that receive satellite signals from an optimally placed antenna and retransmit them. The repeaters are located primarily in built-up areas, where loss of the satellite signal is most likely to occur. ....

Sirius uses a trio of Loral FS1300 satellites in unique elliptical orbits in an effort to avoid the problems posed by geostationary satellites.

The orbits, shaped like figure eights, allow the satellites to appear higher in the sky than XMs, cutting down on the potential for a listener to be out of range of a satellite signal -- and allowing Sirius to have a much smaller number of repeaters."

Care to rethink your stance? :p

Nope.

The effort to avoid geosync problems creates its own problems as noted above and I can drive you to exact locations in multiple cities where the Sirius repeater signal stops and another kicks in - causing a line that drops the signal everytime you cross - something that should not happen if the system worked as you noted.
 
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digiblur

digiblur

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Jun 8, 2005
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Louisiana
HDTVFanAtic said:
Because truth be know, Satellite Radio is BS.

98% of the time you are listening to the local repeater that is ground based.

Driving CrossCountry you might actually be listening to the satellite.

Big FAT negative on that, sir. Does 98% of the community live near repeaters? Big FAT negative again.

I live in an area with ZERO repeaters. The signal will work in my carport also. The closest repeater is over an hour away from me and my radio never picks it up. The only dropouts I ever have is under a metal roof at a gas station, under a concrete overpass, etc. I constantly drive down country roads with heavy tree coverage and never have any drop outs. Sounds like you had a problem with your equipment. I would never change back to FM as I want to listen to the music and content I want to listen instead of what the FCC wants me to listen to.

Enjoy your censored commercial break bloated FM.
 
digiblur

digiblur

SatelliteGuys Master
Jun 8, 2005
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Louisiana
damaged said:
"System design: Satellite radio uses the 2.3 GHz S band in North America, and generally shares the 1.4 GHz L band with local Digital Audio Broadcast (DAB) stations elsewhere. It is a type of direct broadcast satellite, and is strong enough that it requires no satellite dish to receive. Curvature of the Earth limits the reach of the signal, but due to the high orbit of the satellites, two or three are usually sufficient to provide coverage for an entire continent.

Local repeaters similar to broadcast translator boosters enable signals to be available even if the view of the satellite is blocked, for example, by skyscrapers in a large town. Major tunnels can also have repeaters. This method also allows local programming to be transmitted such as traffic and weather in most major metropolitan areas, as of March 2004.

Source: http://en.wikipedia.org/wiki/Satellite_radio

XM and Sirius do not use the L band for downlink.
 
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hahler2

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Jan 14, 2005
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Ashton, SD
Actually it does depend on where you live. If you're in the middle of nowhere like I do you're using the actual satellite signal 99.9% of the time. I only am on a repeater when I travel to Minneapolis.
 
coolbreeze

coolbreeze

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Jul 11, 2006
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Easton, PA
I have Sirius and XM. Never used a repeater and love every second of the programming. No way no how could I ever return to old fashioned radio. Not a chance.
 
HCI

HCI

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Jun 19, 2005
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land of the ice and snow
I noticed the futher north you get the less and more open space between the repeaters on Sirius.

I suppose this is because the signal is higher in the sky.
 
H

HDTVFanAtic

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May 23, 2005
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digiblur said:
Big FAT negative on that, sir. Does 98% of the community live near repeaters? Big FAT negative again.

Actually they do.

Using your numbers ....

98% of the COUNTRY might not be in the range of a repeater, but 98% of the POPULATION is. Remember Directv has covered 50% of the Nation's population with HD-LIL in 35 markets.

No doubt there is a market for Satellite Radio. No one is debating that. How they work technically is very clear. Their engineers even admit that they system will not work without repeaters.

Just the fact that your carport can see the satpath while the direction the gas station awning positions you should speak volumes.

All you have to do is read your post and think about it.
 
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