maartena
Super Grover
Premium
join:2002-05-10
Orange, CA
 ·RoadRunner Cable
| reply to NOCMan
Re: Why not for the US?
said by NOCMan  :Only 1W? QUESTION:
What's the power for Cassini's transmitter?
ANSWER from FAQ on June 3, 1999:
It's 20 watts. Received at the DSN antennas, the signal power is 10 to
the -16th (0.0000000000000001) watts. From Saturn, the signal takes
about 1 hour and 20 minutes to reach Earth.
Conclusion: You don't need a whole lot of power to send a signal.... and to receive a signal, you need even less. 
--
"Any society that would give up a little liberty to gain a little security will deserve neither and lose both" -
Benjamin Franklin, Founding Father. |
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MZR
join:2006-08-12
TX
| reply to NOCMan
I agree with you, but remember,in a sat terminal you are amplifying a wide spectrum(multiple channels). A direcway, any other residential sat setup only needs to amp a small carrier.
It is just like many Wireless ISPs that use 5 and 10MHz channel widths to increase range instead of the standard 20MHz Wi-Fi channels.
I was a direcway customer about 5 years ago and used to lose sync every time a dark cloud got in the way.
BTW, I still have the equipment, If anyone wants it. |
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verolom
join:2002-03-23
Eagleville, PA
·Comcast
| reply to fireflier
Yes, but antennas are hardware. Wi-Fi gear uses a half-dipole with a tiny 2.16 dBi gain and this article claims using existing Wi-Fi gear. Also consider the carrier frequency, noise figure and lack of line-of-sight (multiple reflections).
Allow me to remain a skeptic... |
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NOCMan
Verizon Fios User
Premium
join:2004-09-30
Flower Mound, TX
| reply to fireflier
Only 1W? How high up are those satellites? I've ran setups to 23,000miles and we'd have to push a few dozen watts just to get through heavy clouds and a lot more if it was raining really bad.
--
Mac Chatter
»www.macchatter.net |
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fireflier
Coffee. . .Need Coffee
Premium
join:2001-05-25
Limbo | reply to MZR
Well, that and HIGHLY directional antennas. . . |
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MZR
join:2006-08-12
TX | reply to verolom
It is possible, LOS is the keyword. Ever thought how the 1W transmitters in the directway satellite systems can reach a satellite that is 22,000 miles away? LOS... |
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verolom
join:2002-03-23
Eagleville, PA
·Comcast
1 edit | reply to MrBentor
Yes, if I brush my teeth once a month
I'll believe this when I see it. There is no way a 100 mW transmission can traverse 60 miles (line of sight I presume -- useless), especially with all the interference in the 2.4 GHz band. Software is good but not that good. |
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