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Re: [IRCA] Puyallup, WA Ultralight TP's for 10-12
- Subject: Re: [IRCA] Puyallup, WA Ultralight TP's for 10-12
- From: D1028Gary@xxxxxxx
- Date: Wed, 13 Oct 2010 00:49:01 EDT
Hi Walt,
When I saw your report this morning, it sounded like we were DXing through
different ionospheres!
This location is a notorious DU-dead zone (with only 738-Tahiti and a few
weak Kiwis ever making it here over three years), so I'm not surprised that
your diverse DU-DX didn't show up at all here. But the fact that you had
none of the enhanced Japanese was really strange-- there seemed to be a total
reversal of propagation somewhere between us. Certain Japanese had
freakishly strong signals here, just like two days ago.
I'll paste Mark Connelly's comments on "chordal mode propagation"
(originally on the Ultralightdx list) below. Yes, I'll be eager for tomorrow
morning, also!
73, Gary
____________________________________________________________________________
___________
>From Mark Connelly:
I think you may have hit a case of "chordal mode" propagation just before
dawn fade-out when a tilt in the reflecting layer sends the signal
"sideways" just below the arc of that reflecting layer as it stays roughly
parallel to the earth's surface. When it intersects that arc towards the other end
of the signal path, you have avoided several lossy bounces off the earth.
This causes a significant signal boost, typically for a short time interval
(though obviously longer than meteor scatter on FM). Transmitting and
receiving antennas that have high angle patterns, usually poor antennas for DX,
can actually be quite effective. Spain on 1359 has such an antenna and can
briefly blast in here on the US East Coast at its local dawn, even though
it is mediocre most of the evening.
Mark Connelly, WA1ION
In a message dated 10/12/2010 9:36:30 P.M. Pacific Daylight Time,
canswl@xxxxxxxxx writes:
Now that is indeed VERY interesting, Gary. You saw my report which was
essentially 100% DU on many frequencies! This occurred with my
predominantly Asian corner-fed loop, and a DU oriented ALA 100. I'll look
forward to tomorrow for sure! ...Walt
On Wed, Oct 13, 2010 at 1:23 AM, <D1028Gary@xxxxxxx> wrote:
> Hello All,
>
> Yesterday's comatose TP propagation gave way to some of the
strangest
> Asian conditions ever observed here. Whereas Nick had all-DU propagation
> this morning, here it was strangely slanted toward the Japanese, with a
> minor Korean presence. The Chinese were shut out completely, which led
to
> some
> bizarre receptions on certain frequencies. It certainly seemed like
> another
> example of "chordal mode" propagation, explained by Mark Connelly and
Gary
> Deacon on the Ulralightdx list two days ago.
> The biggest surprise was tuning in to 738 kHz around 1355 and
finding
> a station in (apparent) Japanese all alone, without a trace of BEL2 or
> HKLG-- the usual occupants of the frequency. This mystery station had
the
> frequency all to itself for about 3 minutes, prior to the 1400 TOH. On
594
> kHz
> a moderate-strength JOAK was joined by a co-channel at 1358, as the
fairly
> rare 10 kw KBS1 station apparently made its first appearance of the new
> season. The 1400 TOH recording of 594-JOAK produced a weaker set of time
> pips
> before the 3 + 1 NHK pips, along with Korean-sounding speech from the
same
> female voice observed last November, both before and after the 1400 TOH.
> 1134 kHz had a vibrant JOQR all alone on the frequency, fighting the
1130
> domestic splatter without any Asiatic competition. It usually is a poor
> third
> to KBS and CNR1 this time of year here, and was first heard alone like
> this
> during the weird "chordal mode" propagation two days ago, as explained
by
> Mark. Another strange signal was weak, lengthy instrumental music
dominant
> on 639 kHz around 1350, without any sign of CNR1's usual male-female
> Chinese, and not // 594 kHz. Although there were no ID clues or
parallels
> to
> check, this may have been the 50 kw KBS3 station (possibly heard here
last
> week, under CNR1), showing up with the same instrumental music format.
By
> 1407
> there was a mix on 738 kHz, as apparent Korean from HKLG joined the UnID
> Japanese-- still with no sign of Taiwan's Chinese speech or pop music.
The
> mystery stations on 738, 594 and 639 kHz this morning were not strong,
but
> were easily audible with headphones (which are recommended for MP3
> listening). Even though most of this morning's TP-DXing action was at
> modest signal
> levels, compared to yesterday's near-comatose band, it was a pretty
> thrilling session.
>
>
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