Satellite Radio?
-
Roger Wright wrote: It really doesn't take much power I wish I had time to do some research on it. I'm a former Navy electronics technician so I'm fairly comfortable with the physical principles involved. But I just can't seem to get my head around the notion of that signal being picked up reliably by a device I can carry around in my hand - while inside my car. Roger Wright wrote: satellite transmitters have antennas that focus all of the output power into a relatively small part of the sky Which explains how a dish in your backyard works - pointing at that small area of the sky. The reciever in my car ain't pointing at nothing.
Stan Shannon wrote: Roger Wright wrote: satellite transmitters have antennas that focus all of the output power into a relatively small part of the sky Which explains how a dish in your backyard works - pointing at that small area of the sky. The reciever in my car ain't pointing at nothing. I think Roger was talking about the transmitters being directed earthward, not the receivers directed skyward. From the satellite's perspective earth is ball of diameter 12 at a distance of 35. A bit of trig reveals that all its energy can be focused into a beam with a spread of less tha 20 degrees and still cover all of the "visible" side of Earth. In reality they probably focus a satellite on a smaller target than the entire planet. Steve T
-
I'm thinking about getting satellite radio for my car. Is anyone useing it? Any opinions pro or con? It seems to be a very reasonably priced service if it performs as well as they claim. I have to say that I'm a bit perplexed in regard to how this technology works. I can understand that a satellite could produce enough energy to be picked up by a dish in your back yard. But it seems that to be picked up by a tiny little reciever in your car it would need the equivalent of a nuclear reactor in orbit pumping out a hundred billion watts of radio energy, or very numerous satellites in very low orbit. In either case, it would seem to be a very expensive operation to be offered for a mere $13/month.
Not much more than GPS. The big enabling technolongy on this stuff has been the improved sensitiivity of receivers which as made many systems possible. 3G phones work with signals down to -120dBm, that is 10 to the minus 15th of a watt. In technical terms it's teenteenweeny ;) Elaine (sensitive fluffy tigress) The tigress is here :-D
-
I'm thinking about getting satellite radio for my car. Is anyone useing it? Any opinions pro or con? It seems to be a very reasonably priced service if it performs as well as they claim. I have to say that I'm a bit perplexed in regard to how this technology works. I can understand that a satellite could produce enough energy to be picked up by a dish in your back yard. But it seems that to be picked up by a tiny little reciever in your car it would need the equivalent of a nuclear reactor in orbit pumping out a hundred billion watts of radio energy, or very numerous satellites in very low orbit. In either case, it would seem to be a very expensive operation to be offered for a mere $13/month.
I realize that Satelite Radio is a subscription based service, but if a person has a radio receiver, wouldn't they therefore be able to get the broadcasts? Or does it work like satelite tv service in that there is a card in the receiver box that is activated by the subscription company? I guess a signal is beamed down from the satelite to do this.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
-
Thanks, Mike. On that recommendation, I think I will make the plunge. Although, I'm thinking about Sirius rather than XM. I wouldn't think that there would be much difference between the two services.
Stan Shannon wrote: I wouldn't think that there would be much difference between the two services. For all intents and purposes, probably not. The only big difference that I can see, not that it matters, is that Sirius does not use GEO satellites.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
-
The company i work for do GPS stuff and we have blue tooth gps recievers that you can put in your pocket and walk around with. They are about the size of two match boxes and run for a few days on the internal battery.
Josh, I'm just curious what company this is. I work for Timex and we have a GPS based speed and distance system for athletes. We can't get anything as small as your talking about. Here[^] is some more info about our products. By the way, our first generation product used a Garmin designed device, while our current products use Navman technology. Regards, Brigg Thorp Senior Software Engineer Timex Corporation
-
I'm thinking about getting satellite radio for my car. Is anyone useing it? Any opinions pro or con? It seems to be a very reasonably priced service if it performs as well as they claim. I have to say that I'm a bit perplexed in regard to how this technology works. I can understand that a satellite could produce enough energy to be picked up by a dish in your back yard. But it seems that to be picked up by a tiny little reciever in your car it would need the equivalent of a nuclear reactor in orbit pumping out a hundred billion watts of radio energy, or very numerous satellites in very low orbit. In either case, it would seem to be a very expensive operation to be offered for a mere $13/month.
Always wanted to know, if it's Satellite, does not have 2 way comunication, how can they make you pay? if you have a receiver, you will receive the broadcast. What technology are they using for stopping your receiver to receive the signal? Monthly broadcast key? Thanks Al
-
I realize that Satelite Radio is a subscription based service, but if a person has a radio receiver, wouldn't they therefore be able to get the broadcasts? Or does it work like satelite tv service in that there is a card in the receiver box that is activated by the subscription company? I guess a signal is beamed down from the satelite to do this.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
I just asked that! I should read all msg before posting a new one. Sorry Al
-
The company i work for do GPS stuff and we have blue tooth gps recievers that you can put in your pocket and walk around with. They are about the size of two match boxes and run for a few days on the internal battery.
I am curious too, our units are of similar size as the Timex link. I have seen units that "seem" smaller (micro Unmanned aerial vehicles) where they hide the antenna in a structure that already exists (like a tail fin) -- co-use type activity. It's easy to get GPS on a chip toss away all the screens, map processing, pathing, etc. and you have a very compact unit that just reports position. And the antenna still is about the size of the timex one. _________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
-
I realize that Satelite Radio is a subscription based service, but if a person has a radio receiver, wouldn't they therefore be able to get the broadcasts? Or does it work like satelite tv service in that there is a card in the receiver box that is activated by the subscription company? I guess a signal is beamed down from the satelite to do this.
"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown
I don't do satelite comm work, but I do a lot of one-way messaging to mass unit entities through a variety of mediums. It's pretty easy to embed an activator signal based on serial number registered by the subscription service, pulse and repeat over and over on its own channel. If you don't get that activator signal in x number of minutes, the device doesn't work. I would expect that their process is at least similar. I would check the manual and where it says how long to leave the unit on for activation the first time, you have your biggest clue. _________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
-
I'm thinking about getting satellite radio for my car. Is anyone useing it? Any opinions pro or con? It seems to be a very reasonably priced service if it performs as well as they claim. I have to say that I'm a bit perplexed in regard to how this technology works. I can understand that a satellite could produce enough energy to be picked up by a dish in your back yard. But it seems that to be picked up by a tiny little reciever in your car it would need the equivalent of a nuclear reactor in orbit pumping out a hundred billion watts of radio energy, or very numerous satellites in very low orbit. In either case, it would seem to be a very expensive operation to be offered for a mere $13/month.
My dad and I love our XM radios...we mostly listen to the talk channels; XM Comedy - 150 (R rated comedy), America Right - 166, NASCAR Radio - 144, and ABC News - 124 (for Hannity). I don't listen to FOX News, the exception being June 5th, 2004. Probably the only downside to XM is that they have Laura Ingraham's show on from noon to 3, the same time as Rush. James
-
Stan Shannon wrote: Roger Wright wrote: satellite transmitters have antennas that focus all of the output power into a relatively small part of the sky Which explains how a dish in your backyard works - pointing at that small area of the sky. The reciever in my car ain't pointing at nothing. I think Roger was talking about the transmitters being directed earthward, not the receivers directed skyward. From the satellite's perspective earth is ball of diameter 12 at a distance of 35. A bit of trig reveals that all its energy can be focused into a beam with a spread of less tha 20 degrees and still cover all of the "visible" side of Earth. In reality they probably focus a satellite on a smaller target than the entire planet. Steve T
FlyingTinman wrote: I think Roger was talking about the transmitters being directed earthward, not the receivers directed skyward. From the satellite's perspective earth is ball of diameter 12 at a distance of 35. A bit of trig reveals that all its energy can be focused into a beam with a spread of less tha 20 degrees and still cover all of the "visible" side of Earth. In reality they probably focus a satellite on a smaller target than the entire planet. I know, but still you are pointing your satellite dish at the satellite, which means at the area of the sky that the satellite is directing its energy towards. So it stands to reason that the dish is going to pick up a fairly weak signal. "Capitalism is the source of all true freedom."
-
My dad and I love our XM radios...we mostly listen to the talk channels; XM Comedy - 150 (R rated comedy), America Right - 166, NASCAR Radio - 144, and ABC News - 124 (for Hannity). I don't listen to FOX News, the exception being June 5th, 2004. Probably the only downside to XM is that they have Laura Ingraham's show on from noon to 3, the same time as Rush. James
James T. Johnson wrote: Probably the only downside to XM is that they have Laura Ingraham's show on from noon to 3, the same time as Rush. Well, dang, that'll never do! :-D "Capitalism is the source of all true freedom."
-
I don't do satelite comm work, but I do a lot of one-way messaging to mass unit entities through a variety of mediums. It's pretty easy to embed an activator signal based on serial number registered by the subscription service, pulse and repeat over and over on its own channel. If you don't get that activator signal in x number of minutes, the device doesn't work. I would expect that their process is at least similar. I would check the manual and where it says how long to leave the unit on for activation the first time, you have your biggest clue. _________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
If I understand this right it means that the signal isn't encrypted, just the device is activated. Regardz Colin J Davies The most LinkedIn CPian (that I know of anyhow) :-)
-
Thanks, Mike. On that recommendation, I think I will make the plunge. Although, I'm thinking about Sirius rather than XM. I wouldn't think that there would be much difference between the two services.
I used to write call center software for a retailer of both services. Miserable job, but I digress. I had a few chances to get either for free and never got on the bandwagon. I bought XM a few months ago and I love it. I should have taken them up on the free deal when I had the chance. I, personally, am a huge fan of XM 53. Fungus radio, 24 hours of punk... :) XM raised their rates last month, but you get the internet radio service included in the price, it used to be extra. Ed Atwell
-
If I understand this right it means that the signal isn't encrypted, just the device is activated. Regardz Colin J Davies The most LinkedIn CPian (that I know of anyhow) :-)
It cannot be encrypted on a per unit basis, because you do not know what units have been activated. It can be encrypted using proprietary fixed key encryptions, or rotating keys based on date or other fixed criteria. _________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
-
FlyingTinman wrote: I think Roger was talking about the transmitters being directed earthward, not the receivers directed skyward. From the satellite's perspective earth is ball of diameter 12 at a distance of 35. A bit of trig reveals that all its energy can be focused into a beam with a spread of less tha 20 degrees and still cover all of the "visible" side of Earth. In reality they probably focus a satellite on a smaller target than the entire planet. I know, but still you are pointing your satellite dish at the satellite, which means at the area of the sky that the satellite is directing its energy towards. So it stands to reason that the dish is going to pick up a fairly weak signal. "Capitalism is the source of all true freedom."
Stan Shannon wrote: I know, but still you are pointing your satellite dish at the satellite, which means at the area of the sky that the satellite is directing its energy towards. So it stands to reason that the dish is going to pick up a fairly weak signal. Yup, sounds right. This technology obviously can't work. I wouldn't buy it. ;) Steve T
-
I am curious too, our units are of similar size as the Timex link. I have seen units that "seem" smaller (micro Unmanned aerial vehicles) where they hide the antenna in a structure that already exists (like a tail fin) -- co-use type activity. It's easy to get GPS on a chip toss away all the screens, map processing, pathing, etc. and you have a very compact unit that just reports position. And the antenna still is about the size of the timex one. _________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)