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Old April 18th 09, 01:27 PM posted to rec.radio.shortwave
dave dave is offline
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First recorded activity by RadioBanter: Jan 2009
Posts: 5,185
Default Ibiquity IBOC - no hd radio upgrade needed!

Telamon wrote:


Well, how about analog? I have some hiss in there all the time and often
times warbling rumble kind of noise. It's very annoying and I wish they
would turn that HD crap off.


The IBOC signal is either side of the AM carrier. Each IBOC sideband is
identical but out-of-phase with the other. The theory is the IBOC
sidebands cancel each other out in your receiver. But if one sideband
propagates better than the other (which is always the case once you get
a few miles from the transmitter) the cancellation is not complete.
This is when you hear the digital hash and the wubba-wubba sound.

For those of us using a radio with selectable sideband synchronous
detection, but unable to choose USB and LSB at the same time (like my
Drake SW2) we are forced to listen in plain AM.

Clear Channel has 2 full blown flamethrowers crippled by IBOC in
California now. It's a shame. Citadel gets it. KGO and KKOH do not
use IBOC at night. KFI and KFBK do, and it really diminishes their signals.