Re: [IRCA] Recent DXpedition to Grayland, WA & Florence, OR

[Guy Atkins <dx@xxxxxxxxxxxxx>]

This is getting more and more interesting! Thank you Gary and Bill for the
recent cliffside DXing results, and Nick for sleuthing out the limited
technical papers on this topic.

Some years ago during an annual family vacation to Yachats, Oregon, I was
parked at that exact spot of Gary's wonderful receptions, wondering if that
might be a good place to DX-- if only an antenna could be devised. I was
still in the mindset of large passive antennas like a Beverage or a lengthy
active loop array being the only way to seriously DX. One look over the
guard rail, down that steep cliff to the crashing surf below convinced not
to try anything crazy like an impromptu vertical antenna!

Gary's boldness to blaze the trail by DXing with an FSL between cliff and
traffic dangers at this beautiful, coastal Oregon location has gotten me
interested in figuring out a way to try a different way to DX from this
wide spot in the road. I'm looking forward to giving it a try in early
September. My goal is to be able to make broadband Perseus SDR recordings
from the relative safety of a vehicle at this DX-friendly cliff QTH on
Oregon's Highway 101.

My wife doesn't know it, but her SUV is about to become a PRV... (Perseus
Recording Vehicle  :^)

Guy Atkins
Puyallup, WA



> Date: Wed, 8 Aug 2012 01:30:47 -0400 (EDT)
> From: d1028gary@xxxxxxx
> To: irca@xxxxxxxxxxxxxxxx
> Subject: Re: [IRCA] [NRC-AM] Recent DXpedition to Grayland, WA &
>         Florence,       OR
> Message-ID: <8CF433E189558A3-168C-3F769@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> Hi Nick,
>
> <<<   But
> there is an empirical gem in the second paper on page 917 concerning
> cliff-side signals:  "...mesurements of the magnetic-field strength
> due to Rome, 845kHz, at the top of Beachy Head (a vertical cliff in
> southern England 160m high), gave results 2.3dB higher than values
> measured on a beach well away from the cliff.  This enhanced filed
> strength is believe to be a purely local effect, associated with the
> sharpness of the cliff edge; 200m from the edge, the measured
> increase was only 0.4dB.   These figures are consistent with the
> theoretical increases in the magnetic and electric fields which occur
> near the apex of a rectangular wedge illuminated by a plane
> wave..."   Interestingly he goes on to say, similar to Bill's point
> about Gary's "extreme DXing" prowess: "....severe practical
> difficulties would attend the siting of an aerial so close to a cliff
> edge."    (hi)   >>>
>
>
> Thanks very much for that "empirical gem" from the Beachy Head study!
>
> It seems that by accidentally setting up on the side of the Cape
> Perpetua sheer ocean side cliff with one of the small footprint FSL
> antennas, I was stumbling across this theoretical 2.3dB gain boost that
> the scientists had considered impractical to exploit. Some of the DU
> signals observed during the Cape Perpetua DXpedition seemed to border
> on science fiction, with even 765-Radio Kahungunu (2.5 kW) pegging the
> PL-380's S/N reading at 25. Apparently the development of the new FSL
> antenna will finally will allow DXers to tap into this ocean cliff
> propagation advantage (assuming that they don't first use up all their
> vacation $$$ by purchasing so many ferrite rods).
>
> 73, Gary DeBock (in Puyallup, WA, USA)
>
>
>
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