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(AM) Crystal Radio & HD Radio

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I know that a crystal radio won't decode the HD Radio part of a hybrid AM + HD Radio signal.

I was wondering if anyone has tried listening to an AM + HD Radio signal with a crystal radio (the AM radio in my 2004 civic didn't have any additional interference on 1190 AM [then Radio Disney] + HD Radio, I didn't try an analog AM radio on this station)?


Kirk Bayne
 
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If the signal is strong enough, it'll work, but the digital sideband hiss will be annoyingly loud because it's not filtering the audio bandwidth down to ~4 kHz like most modern AM radios.
 
kevtronics said:
If the signal is strong enough, it'll work, but the digital sideband hiss will be annoyingly loud because it's not filtering the audio bandwidth down to ~4 kHz like most modern AM radios.
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Not necessarily, I have two different dual I.F. band AM radios that capture the full AM audio bandpass in the "Wide" mode. For example in my area the only AM HD radio station is classical KMZT 1260. Both of my receivers capture the full audio frequency response transmitted by the station (which is close to 10 Khz) There is no audible digital noise in the "Wide" mode, however in the "Normal/narrow" mode, which reduces the response down to probably closer to 3 or 4 KHz you can off-tune the radio up or down about 10 kHz or so and hear the digital sidebands. But in the "Wide" mode they are inaudible.

I must say that I haven't listened to a crystal radio since the one I built when I was about 8 years old. In my area at that time there were only 2 stations that you could hear with a crystal radio, fortunately they were nearly at the opposite ends of the dial, because as you may know, crystal radios although tunable (usually a ferrite slug through a coil) have nearly unlimited bandwidth and are entirely dependent on the stations' signal strength. I was astonished at how good music sounded through this little radio! It sounded much better than the AM section of my dad's Hi-Fi!
 
A crystal radio does not have enough selectivity to keep the IBOC sidebands from getting into the analog audio. Hisssssss.
 
Kelly A said:
Exactly, what's next: Would Marconi's original spark gap transmitter support HD radio?? Freaking bizzaro-world.
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It could be worse... there were those who thought Marconi's system should be only used to wirelessly transmit electricity long distances...this of course would be dangerous and would make modern electronics impossible.
 
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