Being down under i don't see any reason for you to be familiar with Sirius or XM radio, both direct satellite digital audio broadcast systems. Not sure how they do it but it works pretty good here in the USA.
?-)
"Bill Sloman"
In fact, Phil Allison is thoroughly in touch with reality, or what passes for reality around here, and makes himself obnoxious by describing what he perceives in distinctly unflattering terms.
** That remark almost qualifies as fair comment.Is Bill now converted to being a fan ?
Am I slipping ??
How times have changed ...
.... Phil
The question really is how many satellite transponders you can afford to buy.
If you can afford to buy a whole TWT (and associated channel electronics on a satellite) to just send 1 MHz of bandwidth (instead of 27 MHz), the receiver at required bandwidth will get a 15 dB increase in SNR, which in the digital world is a huge advantage.
A few (2-4) independent audio streams could reasonably well be sent through a standard satellite transponder, but will require a significant (several dB) backoff of the TWT in order to remain in the linear region.
As far as I understand, both Sirius and XM use terrestrial gap fillers in urban areas, where the satellite is not directly visible :-).
Oh, come on!
Phil is a refreshing antidote to the many self obsessed septics who infest this group.
I always was a fan.
You are still mostly right, and still ruder than you need to be. I don't see any significant change.
Your memory may be failing ...
-- Bill Sloman, Sydney
ke
Septics? What do you mean? Cockney rhyming slang... "septic tank" = "yank"
Not all the US posters would happy to be called a yankee... which over here mostly refers to the North (during our civil war) and in particular the northeast.
George H.
I've not seen Phil offended by a question. He mainly gets offended when his statements are disregarded.
-- ?? 100% natural --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
"Jasen Betts"
** Give that man a Kewpie doll ......... Phil
Repeating myself, the Costas loop signals are NOT useful for decoding the stereo difference component (S). It can be used to send low speed digital data on the 19 kHz pilot tone.
to the OP George,
Didn't we have this conversation here a few years ago???...
If you want to dig the 19 kHz pilot tone out of the noise, you could take a standard FM receiver and build an AFC loop around it that has a BW that will pass most of the audio so that the AFC will "unmodulate" most of the audio. The resulting signal will be more narrow band so you can then demodulate that with a more narrow passband IF which will yield a better SNR on the 19 kHz pilot.
I'm gonna guess you could improve the pre demodulation SNR by 3 to 6 dB depending on how effective you can AFC out the audio.
What I want to know is WHY anyone would want to do this?
Mark
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