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HD-AM "Fix" for night at Citadel stations = no fix

Savage said:
Some posters think that morphing to all-digital HD-AM will fix the problems? Think again.

Once again the nonnegotiable skywave characteristics of the medium-wave band will frustrate pro-IBOCers. Real-world tests have shown that field strengths of 40 mv/m - EIGHT times what's currently considered "city-grade" on AM - are necessary in most cases for reliable digital decode, in order to overcome skywave interference. This is not a receiver-sensitivity or selectivity issue. This is a reality issue, having everything to do with the non-robustness of the iBiquity digital signal once it's transported out of the test lab.

Even if the most ardent IBOCers "thin the herd" doomsday wishes come true and, say, a third of current AM signals disappear, dropping the aforementioned signal strength requirement for digital to say 25 mv/m there will still be too much skywave noise for HD-AM to work reliably.
Click to expand...

Sorry Bob, it does work. I've demonstrated as much here recently. Five of the six AM iboc stations lock reliably using only the cheap loop provided with the Acurian.

http://www.radio-info.com/smf/index.php/topic,89938.0.html

I know you have filed for a new facility and you'll probably ridicule this suggestion, you would be well advised to consider this system.

Lino
 
Savage said:
Some posters think that morphing to all-digital HD-AM will fix the problems? Think again.

Once again the nonnegotiable skywave characteristics of the medium-wave band will frustrate pro-IBOCers. Real-world tests have shown that field strengths of 40 mv/m - EIGHT times what's currently considered "city-grade" on AM - are necessary in most cases for reliable digital decode, in order to overcome skywave interference. This is not a receiver-sensitivity or selectivity issue. This is a reality issue, having everything to do with the non-robustness of the iBiquity digital signal once it's transported out of the test lab.

Even if the most ardent IBOCers "thin the herd" doomsday wishes come true and, say, a third of current AM signals disappear, dropping the aforementioned signal strength requirement for digital to say 25 mv/m there will still be too much skywave noise for HD-AM to work reliably.
Click to expand...
Is that 40 mv/m number in terms of the analog or digital signal? Remember, the digital signal is 1/100 of the analog signal. Hence, 0.4 mv/m seems like a good number which backs up my unscientific findings I posted in the link below:

http://www.radio-info.com/smf/index.php/topic,82368.0.html
 
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