Hi John B.,

    Thanks for your warm welcome and advice on ducting and dawn enhancement. In fact I have been aware of that for some time and always DX at dawn when I can.

Conditions yesterday at dawn were putrid, but this morning BINGO, the little SRF-39FP surprised me with it's barefoot performance:

 

1557 France Nice, nice and clear - 5400 miles

1521 Saudi Arabia AA - 4400 miles

1539 R. Aap Al dhabbiya UAE - 4,600 miles

1540 ZNSI EE gospel Nassau Bahamas - 7500 miles

1377 R. Free Africa vv Mwanza Tanzania - 2300 miles

1440 time pips and AA NX Damman Saudi Arabia

1503 R Iran AA Bushehr

All at around 0130z and parallel to my giant Cyclops II and DX1 active.

 

I was really amazed and gratified when I got a clear Afro-American spouting hot gospel from Nassau with UAE right on it's shoulder. I never would have thought that such a tiny analogue device could achieve something like this = difficult enough on my big rigs. Pity I have no way of recording this catch, as it would be very interesting. Of course, ZNSI appeared only briefly for a few seconds at a time, as it was mainly overshadowed by the powerful UAE station.

 

Have fun and good DX

 

John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
Icom IC-7700, Icom IC-756 PRO III with MW mods
ERGO software
Drake SW8. Sangean 803A
Sony 7600D, GE SRIII, Redsun RP2100
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop.
http://www.dxing.info/about/dxers/plimmer.dx 

----- Original Message -----

From: John H. Bryant

To: ultralightdx@yahoogroups.com

Sent: Saturday, January 03, 2009 6:23 PM

Subject: [ultralightdx] Re: Welcome Aboard : JOHN PLIMMER

A bit of illness and Holiday celebrations have put me far behind with correspondence.... or I would have been among the first to WELCOME John Plimmer to our Ultralight Community. 

For several reasons, I'm thrilled that he has joined us. First, because John is actually even older than me.... its always comforting to have a few folks out ahead of you on life's winding road.  Secondly, John is the first of what I hope becomes four South Africans to join us here. The four are the hard core of southern African MW DXing and each owns an enviable log book... through their own talent and their fortunate location.  We've compared notes a number of times and have concluded that the South African coast is about as close as civilization has reached to the near perfect MW DXing conditions that I found on Easter Island.... They have a great location!

John, I've been meaning to write to you for some time about the experiences of a good friend of mine, VE7BS, Bob Eldridge.  Bob lives in a narrow valley near Whistler, BC, Canada... the upcoming venue for the Winter Olympics.... Bob is even older than you (obviously an OK guy!) and a vastly experienced radio amateur. His specialty in retirement has been 160 meters (1.8 MHz) over planetary distances. For years, in the 80s and 90s, Bob was one of two North American anchors of something that they called SEANCE.  It was an almost DAILY communications net between Western North America and Eastern Australia + NZ.  Over the first couple of years, they discovered that communications over that path were possible on all but the poorest propagational conditions, often with very modest equipment and antennas.... this was not high-powered, directional stuff. This western NAm to DU link lasted throughout the northern hemisphere Summer 6 months of the year and existed only at Dawn enhancement periods on the North American end.  This kind of link, with modest equipment over several years, in most propagational conditions (at least 50% of the NAm mornings) was considered impossible on 1.8 MHz. until they stumbled on it and then investigated it thoroughly. In the early years of that link, I think that they were unaware of the "Summer DU Season" that was rather familiar to Nick Hall-Patch and others in the MW community.  The two unexpected phenomena were closely related or exactly the same, as far as I can see.

The other piece of this puzzle is that the second North American base station was located in Longmont, Colorado, on the very near east side of the Rocky Mountains. Given the location of the two North American base stations and the relative strengths of signal and lack of power of some of the antenna/tx combinations, some fairly heavy-weight propagational people came to feel that the mode of transmission of these long-haul MW signals was by chordal hop or single-side ducting or similar mode.... not the traditional multi-hop, ground reflection model that most of us visualize.

ANYWAY, the whole point of this story for you, John, is the detailed environment from which VE7BS operates.  The SW, West and NW horizon is totally blocked by the nearby mountains to an angle of almost 45 degrees(the route to Australia is more-or-less West from Bob's place.) When Bob first started hearing the Aussies, he was shocked, given the horizon blockage and supposed low arrival angle of the signals. He did notice about a 30 minute period right before and after local dawn where the signals peaked quite noticeably. His antennas at that time were normal wires, possibly cut to length and possibly a large Delta hung vertically. As they mulled over what they thought was happening, they concluded that at least a significant part of the signals might be arriving at Bob's from a very high angle (vertical?)  Bob hung a Delta loop almost horizontally and it was GREAT....  When he would first hear the Aussies, his low angle antenna worked best, but for a magic 30 minutes or so around dawn, the high angle antenna FAR out-performed his traditional antennas.  On good mornings, the low angle antennas became preferred again very late in the opening, after sun-up.

That experience is the closest that I know about that supports the idea that really long-haul MW signals (at least in the upper half of the band) routinely propagate by ducting or chordal hops and that arrival angles of signals from the dark side (from westerly azimuths) are routinely very near vertical for a period around dawn.

Some of us have noticed supporting trends at Grayland dawn, where the westerly-pointing Beverages routinely seem to lose directivity for a period around dawn.... the NW, W and SW Beverage suddenly are indistinguishable from each other or almost so, for a period of 30 minutes or so at dawn, before directionality returns for the post-dawn late receptions.  This kind of response could also be explained if the arrival angles shifted from low to quite high and then back to low.

This high arrival angle propagation might only be slightly noticeable with normal antennas and receivers, but I suspect that it would leap out at you using a Barefoot Ultralight, John.  Are you like me and many other Old Duffers.... up before dawn on a routine basis???

Glad to hear that you are acquiring an E100 through Guy.  I love the SRF-39FP that you have.... but I USE my E100... You will, too, especially if you are DXing a mixture of 9 and 10 kHz. stations, you are gonna love the E100.

If you find any hint of high arrival angle DX at dawn, I'm certain that we'd all like to hear about it.

WELCOME ABOARD, JOHN!

John B.
Stillwater, OK, USA
Rcvrs: Hotrodded NRD-535, Slider e100's
Antennas: Wellbrook Phased Array

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