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Old July 20th 07, 04:56 AM posted to rec.radio.shortwave
American Insurgent American Insurgent is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 77
Default Identify unknown signal or modulation mode commonly heard in the 1960s

On Jul 19, 11:50 am, BDK wrote:
(snip)
It's an excellent time waster..if you have the patience. Sadly, starting
in the late 80's, a lot of the good stuff, like press photos and ship
traffic began to disappear.


That's because it all went to satellites. Satellites are much more
efficient at digital transmission. Satellite reception for home use
still has a way to go, but satellite usage for data transmission has
just about taken over except when the military wants to be
unpredictable and keep potential eavesdroppers (such as Iran or North
Korea) off guard. If you hear any sort of data today, it's almost
always military. Voice HF utes are mainly used in international
airplane travel and sometimes for older ship to shore rescue dispatch.
(The Canadians still seem to rely on HF a lot for ship rescues.) The
planes and Canadian rescue dispatch from the maritimes is ok, but can
get boring especially if you don't know the jargon.

I never really got into listening to the cops and the firefighters,
most of what they do is pretty dull. Spectacular fires and frantic
"officer down" calls are pretty rare. It got to be that the scanner
craze of the 70s petered out and the only ones listening were the
crooks, in order to avoid the cops. When Johnny Law realized that,
they replaced their radios, kicking them up to the Ghz range and
making the equipment to recieve the "trunks" costly and hard to find.
Nowadays only the old scanner diehards listen to the public servants,
and the crooks aren't organized enough to have somebody listening with
a Trunktracker at a base QTH and then radio info out to the field. I
suppose that Mara Salvatrucha and some of the more organized drug
gangs could pull it off, but they usually don't get beyond cell phone
level of electronic difficulty.