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Re: Topband: UW0MF re: Asian Jammer

To: topband@contesting.com
Subject: Re: Topband: UW0MF re: Asian Jammer
From: VR2BrettGraham <vr2bg@harts.org.hk>
Date: Mon, 24 Oct 2005 17:29:39 +0000
List-post: <mailto:topband@contesting.com>
W4ZV added:

>          Brett, I believe N7UA has come up with a plausible
>explanation.  The recordings by YB5AQB are definitely
>pulsed.  Recordings by N7UA, OH3XR and several JA's are
>more like white noise jamming.  So there may be BOTH an
>OTH radar AND a jammer to counter that radar.  We can
>speculate about a couple of likely possibilities given
>the area's politics:
>
>BY <> BV
>P5 <> HL
>
>I believe it's unlikely that a jammer would suddenly
>appear without a targeted signal to jam.  Let's hope both
>parties tire of this soon.

What I hear from 1690-1935 kc is some sort of gyrating
sound.  This is on an 80m GP.  It seems to be continuous,
with peaks on some frequencies.  The gyrations are too fast,
but there are slower frequency gyrations in there & there
may even be some AM on top of it all.  It's like some big fat
mother of modulated carriers, like a Cray-powered teletype
link sending diddles.

Where this is weak, I don't hear anything underneath it,
though this could be my antenna's response.

Maybe the pulses aren't there all the time?  This is around
16z 2005-10-24.  If YB5AQB can hear pulses, I would think I
should be able to hear them, too.

We would all no doubt love to see the antenna being used if
this 160m woodpecker Bob is hearing has something like
the apparent pattern of the one on 40 from Hainan!

Effectively jamming BV from Shandong or Liaoning is naff,
though silly things should be expected.  I might suggest
adding a demo (BY jamming itself) to that list, but my not
hearing pulses doesn't jive.

My 1998 copy of ITU-RR tells me in R3 amateur is co-
primary with fixed, mobile (except aero) & radionav, with
radioloc secondary (plus footnote on Loran).  OTHR is
radioloc & therefore second fiddle & if either BV or HL
has anything to do with it either way then W probably
already knows about it or maybe is somehow involved.

And seeing how G from ZC4 intrudes into 12 through now
30m on a daily basis, has been doing so for some time & is
well known to be doing so, we might as well get used to it.

Not a pretty picture.  I can almost set my watch based on
when the BY 12m CODAR fires up at the start of each working
day.  In time everyone else will have something like it, too -
anybody hear the W4 OTHR that was featured by VE supplier
of antennas used (which are specified as being for 10 & 7 Mc)?
Wonder who else they have supplied to - there is no radioloc
anywhere close to either of those frequencies in any ITU Region.

The NE monsoon is blowing, so everything smells of the pig
farm up the valley... and there's a foul smell on the bands at
VR2BG, too.  With the wind in the right direction, the pong should
be detectable just about everywhere.

On a positive note, at about 17z I heard 9M2AX calling 9K2MU
on 1832.8, so I'm hearing something on 160 through this stuff!

73, VR2BrettGraham

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