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Best application for HD Radio

ai4i said:
From Orbitcast.com
Click to expand...

I see another possible application for XM's HD FM modulator--a Part 15 realty house advertising transmitter or general-purpose advertising transmitter. These little transmitters are also used for short-range community radio stations.

Right now, Part 15 AM units are preferable for these applications because the allowed AM power level is much higher than for Part 15 FM; the typical AM range is approximately 300' - 3000' as opposed to about 60' - 100' for FM. The HD FM modulator could potentially be clearly received much farther away than this. Now, if XM would make an HD *AM* modulator, that could be very interesting to try out... -- Jason
 
JasonW said:
I see another possible application for XM's HD FM modulator--a Part 15 realty house advertising transmitter or general-purpose advertising transmitter. These little transmitters are also used for short-range community radio stations.
Click to expand...
But, how far would a mediumwave (AM might not be correct here) HD signal be recieved as compared with an analogue signal with reasoable quieting by a car radio? I would guess, not as. This would be a good way to transmit music around ones own property or small parcel of property.
 
ai4i said:
JasonW said:
I see another possible application for XM's HD FM modulator--a Part 15 realty house advertising transmitter or general-purpose advertising transmitter. These little transmitters are also used for short-range community radio stations.
Click to expand...
But, how far would a mediumwave (AM might not be correct here) HD signal be recieved as compared with an analogue signal with reasoable quieting by a car radio? I would guess, not as. This would be a good way to transmit music around ones own property or small parcel of property.
Click to expand...

Part 15 AM transmitters are allowed to have output powers up to 100 milliwatts, which is much higher than the allowed Part 15 FM output power (which for FM, is based on the field strength measured 3 meters from the antenna). With good grounding and an antenna mounted in the clear, a Part 15 AM transmitter can be clearly received up to a mile or more away, and that's with an analog signal.

An HD AM transmitter operating under the same Part 15 AM rules (100 milliwatt output power, 3 meter total antenna + antenna feedline [if any] + ground lead length, harmonic emissions at least 20 dB below carrier) might be able to considerably exceed the range of an analog Part 15 AM transmitter. -- Jason
 
JasonW said:
An HD AM transmitter operating under...Part 15 AM rules...might be able to considerably exceed the range of an analog Part 15 AM transmitter. -- Jason
Click to expand...
In the full HD mode.
In the hybrid mode, the analogue range always outdistances the digital.
I would like to see digital part 15 mediumwave transmitters.
As soon as the ig al ets eak or the in erence evel ises, the bit error ate terqx gralhmpm klupmphq.
You get the pic ;)
 
ai4i said:
From Orbitcast.com
Click to expand...

An OK idea but according to Orbitcast's article, the XM digital stream is brought down to analog, and re-coded to HD. Still, there will be loss and artifacts compared to a patch cord directly into an audio jack. And...this technique is widely used prior art...how is it supposed to be patentable?
 
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