[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [IRCA] Oregon Cliff (Cape Perpetua) Ultralight TP's and DU's for 8-19
- Subject: Re: [IRCA] Oregon Cliff (Cape Perpetua) Ultralight TP's and DU's for 8-19
- From: d1028gary@xxxxxxx
- Date: Wed, 21 Aug 2013 00:41:07 -0400 (EDT)
Hi Derek,
The 4 days spent at the Cape Perpetua cliff last week provided the wackiest and wildest DU-DXing sessions that I've ever experienced in six years of TP-chasing. Every morning had a new propagation twist to it-- almost like the Cliff was never going to let you discover its propagation secrets. Wish that you could have been there!
73, Gary
-----Original Message-----
From: Derek Vincent <eargazimm@xxxxxxxxx>
To: Mailing list for the International Radio Club of America <irca@xxxxxxxxxxxxxxxx>
Sent: Tue, Aug 20, 2013 9:12 pm
Subject: Re: [IRCA] Oregon Cliff (Cape Perpetua) Ultralight TP's and DU's for 8-19
Gary's reports always amaze me... Now I'm cliff top waiting : )
And yes it's very dark : ) just stepped out to water the grounds
Thanks
DerekVmedia@xxxxxxx
ChannelDerek.carbonmade.com
On Aug 20, 2013, at 7:23 PM, Nick Hall-Patch <nhp@xxxxxxxx> wrote:
> Yours are really valid points Mark. Inland definitely can mean considerably
poorer signal strengths, and I would not be surprised if my "usual" sunrise
enhancements on TP signals are due to high arrival angles of the incoming wave
front (see my QEX article of some years ago for that very hypothesis).
>
> I certainly didn't expect anything like Gary's signal levels, but, as Gary
pointed out, Dennis, who is considerably further inland than I also heard a
couple of Asiatics quite well, and I heard practically nothing, even carriers.
In this case, it may have been that the farther north path to my location from
Asia had some attenuation on it that didn't affect the more southerly paths,
though conditions were not particularly auroral. Generally this summer, Dennis
and I have heard similar Asiatics on any given morning, on the rare mornings
that Asiatics were to be heard, though he does better on the longwave Russians,
and indeed on MW Asians as fall approaches.
>
> Thanks for your thoughts. Propagation continues to be mysterious!
>
> best wishes,
>
> Nick
>
>
>
>
>
> At 21:34 20-08-13, you wrote:
>
>> <<
>> It's hard to believe that we were listening on the same planet Gary,
>> let alone the same coast, though admittedly, I'm quite a way from the
>> open Pacific here. As I said yesterday, that morning was pretty
>> much the biggest stinker this summer here.
>>
>>
>> best wishes,
>>
>>
>> Nick
>> >>
>>
>>
>> My home locations have always been a fairly easy commute to TA-capable shore
sites:
>> e.g.
>> Arlington, MA: 7 miles (11 km) to Revere Beach
>> Sudbury, MA: 20 miles (32 km) to Boston waterfront
>> Billerica, MA: 15 miles (24 km) to Salem / Marblehead
>> South Yarmouth, MA: 12 miles (19 km) to Chatham / Orleans
>>
>>
>> These are air distances for typical 50-75 degree Euro bearings. Road
distances to DXpedition sites are typically a bit more if only because the shore
is heavily developed and only offers certain areas useful for DXing from the
car. In my present case (S. Yarmouth), because of the contour of the shore, the
drive to a usable site is actually shorter than the 50-75 degree bearing air
distance house-to-shore.
>>
>>
>> In all cases, the differences between home sites and the coastal DXpedition
sites are HUGE. Some stations were routinely 30-40 dB stronger at the Granite
Pier site in Rockport, MA versus less than an hour's drive away at Billerica.
The 1544 (later 1550) Algerian clandestine station was one station which
consistently exhibited this whopping difference. Long term comparisons were
easy to make since I could use the same in-car receiver and rooftop antenna.
>>
>>
>> East Coast inland versus shore differences are greatest in pre-sunset initial
fade-ups and during aurora. The thinking is that the lower the arrival angle of
the incoming station, the more difference near-field ground conductivity makes.
There are numerous stations that cannot be heard at home sites on big antennas
yet can be heard from time to time on a 2m by 2m car-roof loop at nearby beach
sites.
>>
>>
>> If a station arrives at a higher angle, the location characteristics are less
critical and your inland signal may only be 15 to 20 dB degraded from what is
noted at the shore. Old 1314 Norway during prime high latitude conditions (in
mid/late evening) fell into this category. Sunrise at the European transmitter
end could contribute to a higher incoming angle at the USA receiving end because
an ionospheric tilt may contribute to fewer skip hops being required.
>>
>>
>> On groundwave, as with low-angle skip, the differences are huge. V-Soft shows
660 WFAN (NYC) running 6.24 mV/m at Falmouth, MA 02543 (shore) and 0.45 mV/m at
South Dennis, MA 02660 (about 15 miles / 24 km inland for 255 degree bearing
towards station). In decibels, this equates to a 23 dB drop - and that's for a
LOW-band station. A high-band station would show an even greater overland
signal deterioration. The V-Soft groundwave variations don't look too different
from what is routinely observed with low-angle long-haul DX skip.
>>
>>
>> Mark Connelly, WA1ION
>> South Yarmouth, MA
>> _______________________________________________
>> IRCA mailing list
>> IRCA@xxxxxxxxxxxxxxxx
>> http://montreal.kotalampi.com/mailman/listinfo/irca
>>
>> Opinions expressed in messages on this mailing list are those of the original
contributors and do not necessarily reflect the opinion of the IRCA, its
editors, publishing staff, or officers
>>
>> For more information: http://www.ircaonline.org
>>
>> To Post a message: irca@xxxxxxxxxxxxxxxx
>
>
> _______________________________________________
> IRCA mailing list
> IRCA@xxxxxxxxxxxxxxxx
> http://montreal.kotalampi.com/mailman/listinfo/irca
>
> Opinions expressed in messages on this mailing list are those of the original
contributors and do not necessarily reflect the opinion of the IRCA, its
editors, publishing staff, or officers
>
> For more information: http://www.ircaonline.org
>
> To Post a message: irca@xxxxxxxxxxxxxxxx
>
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca
Opinions expressed in messages on this mailing list are those of the original
contributors and do not necessarily reflect the opinion of the IRCA, its
editors, publishing staff, or officers
For more information: http://www.ircaonline.org
To Post a message: irca@xxxxxxxxxxxxxxxx
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca
Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers
For more information: http://www.ircaonline.org
To Post a message: irca@xxxxxxxxxxxxxxxx