Re: [HCDX]: Vatican Radio on 527 kHz
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Re: [HCDX]: Vatican Radio on 527 kHz

In a message dated 11/10/99 10:32:09 Eastern Daylight Time, bportzer@xxxxxxxx 

<<  just a guess, since I live several thousand miles from the station.  If
 they're only using USB+carrier on 527, it may be to avoid interfering with
 maritime services on or around 500 kHz.  500 kHz until recently was used by
 ships in distress to send S-O-S, and some coastal stations operate 
 between 510 and 526 for more routine cw traffic. >>

Hello, this not a likely reason, but there is the NAVTEX  RTTY service at 518 
khz which might require interference protection. There's also the chance that 
they figured that most AM radios don't really get below 531 kHz anyway, and 
sending the lower sideband was a waste of energy. 

All you need to demodulate an AM signal is either the upper OR the lower 
sideband, and the carrier, but you can recreate the carrier in the radio, so 
all you need over the air is one of the sidebands. However, if there's no 
carrier, you must have either a BFO or a sideband detector in the receiver.
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