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Author Topic: K9LA ARTICLE: VK4YB to NO3M on 630m and 2200m  (Read 196 times)

WA2ONH

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K9LA ARTICLE: VK4YB to NO3M on 630m and 2200m
« on: December 03, 2019, 06:53:54 AM »

From K9LA's Amateur Radio Propagation Web Site
http://k9la.us/

NEW for December 2019 in the "Monthly Feature" link: VK4YB to NO3M on 630m and 2200 http://k9la.us/Dec19_VK4YB_to_NO3M_on_630m_and_2200m.pdf

"Eric NO3M and Roger VK4YB completed a 630-Meter QSO on October 14 of this year at 1032 UTC using
the JT9 mode. This is a new distance record (14,979 km) on our newest MF (medium frequency
300-3000 KHz) band."


Downloads a 4-page 499 kb size PDF File.
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73 de WA2ONH  <dit dit> ... Charlie
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"Never be satisfied with what you know, only with what more you can find out."
   Dr David Fairchild 1869-1954 US Scientist

KM1H

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Re: K9LA ARTICLE: VK4YB to NO3M on 630m and 2200m
« Reply #1 on: December 03, 2019, 01:50:11 PM »

Amazing that he makes no mention of the Grayline Paths which have been used for far more decades by hams going on 80-90 years. That NDB "study" simply confirmed it over short distances which has been well known by the LF BCB listeners, again for as many decades.

Ive even copied SAQ on 17.2 khz 3 times and Im far from alone and far from the longest distance.

With ~ 330 DXCC "entities" on 160 over about 40 years I believe I have a good handle on propagation but far from all the answers.

There were a few really propagation professional and experienced hams that published detailed studies on several paths but I believe they are all dead BUT that info should be online. The Topband reflector would know the details also.

http://lists.contesting.com/mailman/listinfo/topband

Carl

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VK6HP

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Re: K9LA ARTICLE: VK4YB to NO3M on 630m and 2200m
« Reply #2 on: December 03, 2019, 07:21:58 PM »

It was a real achievement by Roger and Eric, and I was impressed.  While the propagation mechanisms remain somewhat unclear, what is clear is the value of having the dedication to simply be there.  That sounds obvious but one of the biggest obstacles on LF/MF, particularly in this part of the world, is the small number of operators, and still fewer willing to keep unsocial hours.

Being an upstart on 630 m this year I was pleased enough to work Roger (3610 km) and another interstate station on JT9 and, with a small interest group here in VK6 now pursuing some interesting MF developments, one of us might even manage to complement those first contacts with some international ones.  I must say, though, that the Indian Ocean is proving more stubborn than the Pacific, although geography and demographics go some way to explaining that.

While I note K9LA's preference for multi-hop propagation in explaining the VK4 - East Coast N. America paths, I'm not aware of any intermediate reception reports, which one might have expected with the listener density in NA.  But that's just an observation; I have no better explanation to offer.

I have found the content of the RSGB LF Group forums (https://groups.io/g/rsgb-lf-group/) to be very interesting, with a number of well-known operators from around the world posting regularly.  There have been some interesting propagation discussions conducted at a pretty high level, and I enjoy seeing the results of European and NA trials of LF encoding/decoding modes which approach the theoretical channel limits.

73, Peter.

« Last Edit: December 03, 2019, 07:32:15 PM by VK6HP »
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