When the Soviets were running OTHR in the amateur bands, (which used the HF
echo to "see" targets) I used QSK CW dits to synchronize with their OTHR pulse
timing and jam their "B" scopes. As a former Radar Electronics Counter-Measures
and Electronics Counter-Counter-Measures operator, I knew it was simply a
matter of transmitting a signal of about the same frequency, duration, and
slightly stronger than their "return" to confuse their operators. By setting my
keyer speed so that I did not hear their pulse while QSK at 100 W and by
calling HH5HH with the beam pointed at the strongest OTHR signal, I'd usually
hear them go QRT or find someplace else to play. Calling HH5HH QSK at the OTHR
pulse rate worked well until the Soviets started using digital signal
processing, then it became a "overload signal game" with less apparent success
in forcing them to QSY or QRT.
By the way my RADAR set back then was a Ten-Tec OMNI-D....
Best regards,
Gary - AB9M
CSM(r)G.L.Huber
glhuber@msn.com<mailto:glhuber@msn.com>
gary.huber@us.army.mil<mailto:gary.huber@us.army.mil>
www.csm-gh.com<http://www.csm-gh.com/>
9679 Heron Bay Road
Bloomington, IL 61704
(309-662-0604)
National Webmaster for:
The Society of the Fifth Division
wm@fifthinfantrydivision.com<mailto:wm@fifthinfantrydivision.com>
www.societyofthefifthdivision.com<http://www.societyofthefifthdivision.com/>
----- Original Message -----
From: Martin, AA6E<mailto:martin.ewing@gmail.com>
To: tentec@contesting.com<mailto:tentec@contesting.com>
Sent: Monday, January 02, 2006 12:20 PM
Subject: [TenTec] Radio Science + QSK = Radar
When operating QSK at 15-20 wpm, I am running into echoes of my
transmissions. These occur on certain azimuth bearings at certain
times of day, most often to the SE, which is over water until hitting
S. Africa or Antarctica from here. I've seen this from 20 M to 15 M,
at least.
Rarely, I think I've seen long-path echoes that come back to me from
the opposite azimuth. (The SteppIR bidirectional mode picks them up.)
More often, the return bearing is the same as transmitting. I haven't
been able to measure the delay time accurately, but it is roughly 2
dit (element) times at 25 wpm (about 50 msec), indicating a 10,000
mile roundtrip.
It seems to be a real effect. I can get rid of it by changing azimuth
or using a dummy load.
My question is whether other ops see this and whether it has been
written up anywhere in "ham space". These are not the "long delay
echoes" that people have claimed to see. The radio science community
does run HF radar to study fluctuations in the ionosphere, and this
phenomenon is probably well known to them.
The Orion makes a fair radar set, as it turns out.
73 Martin AA6E
--
martin.ewing@gmail.com<mailto:martin.ewing@gmail.com>
http://blog.aa6e.net<http://blog.aa6e.net/>
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