Topband: Modeling the proverbial "vertical on a beach"

[Carl]

That was a very interesting post Mark and thanks for taking the time.

In the mid 60's to 80's I was very interested in LF and MF BCB DXing and at 
first I had a loaner HRO-500 (I worked at National 1963-69) and later my own 
with the LF-10 preselector which I still have and use here for general BC 
and SW listening.

Most of the serious listening was at York Beach ME and in the car with the 
receiver on its own 12V car or lawn tractor battery. My inlaws had a summer 
cottage under a quarter mile inland. Antennas at first were simple wires on 
tripods going from the US RT 1A beach road right into the water about 
100-150' away or parallel to it, they were fairly directional. Later I used 
short terminated Beverages pointed at EU, AF, and SA and switch selectable; 
these even had excellent directivity on LF. The York Beach cops were 
tolerant and then downright friendly over time and even bringing me hot 
coffee in the winter as Id often be there until midnight!

Random weekend experiments with Beverages running along the cottage 
"development" dirt paths after the summer residents left were mixed results 
with sometimes big grayline enhancements and also sunrise at the eastern 
end. The Carribean and SA was usually a dud as it was almost 2 miles over 
high loss sand before getting to the ocean again. At this time the Beverages 
were in the 600' range and about 8' high running thru trees and shrubs so 
the cops could patrol. While no direct comparisons with the ones at the 
water were made they were felt to be well down in performance but better 
than at home in Raymond or Pelham NH.

Having only paper bulletins or SWL magazines in the days before Al Gore 
invented the Internet were frustrating to say the least and getting ID's was 
often guesswork. I had a battery operated tape recorder for deciphering at 
home and I often played them at work to coworkers inorder to determine the 
language.

In 1989 I moved about 5 miles to a roughly 675' high hilltop still here in 
Pelham with an elevation drop of 300-500' within 1.5 miles or less over 360* 
and 5 acres of my own plus access to about 400A more of which Ive only used 
a tiny amount of that for Beverages in order to get away from a couple of RF 
noisy neighbors. It is the highest point in about 20 miles and downhill to 
the Atlantic over a wide azimuth. For the most part I hear quite well, 
especially on 160/80.

Most current MF/LF DXing is with either a TS-940 or TS-950SD, both loaded 
with filters.

I know Dallas Lankford but otherwise have had no involvement with the BCB 
DXing community.

BTW, what are the best California BC stations to look for? Its been decades 
since Ive heard one but I havent tried hard at all.

Carl
KM1H




> Some long-time observations from about 55 years of AM broadcast band DXing 
> MAY have some relevance to this discussion.
>
> That hobby has had a lot of simultaneous inland-versus-coastal signal 
> strength comparison studies over the years, largely from the US and 
> Canadian Atlantic and Pacific coasts but also from a variety of other 
> sites around the globe.
>
> Nick Hall-Patch (VE7DXR) and Chuck Hutton (WD4ELO) who comment 
> periodically on this list are both active in both amateur radio and 
> broadcast DXing.  They, along with Bruce Portzer, Guy Atkins, Gary DeBock, 
> Pat Martin, Walter Salmaniw, Dallas Lankford, and others have done a lot 
> of DXing at prime sites along the Oregon, Washington, and British Columbia 
> coast.
>
> Here on the East Coast, many observations have been done by enthusiasts 
> such as Bruce Conti, Neil Kazaross, Ben Dangerfield, Jean Burnell, Marc 
> DeLorenzo, and myself.  Both simultaneous listening at various sites and 
> long-term observations from somewhat-inland and "beach DXpedition" sites 
> have given rise to a number of findings.  There could be at least a 
> certain amount of crossover relevance to 160m and perhaps even 80/75m.
>
> Here are a few conclusions:
>
> * The advantages of being at the shore are substantial in the pre-sunset 
> period along east-facing shorelines and post-sunrise along west-facing 
> shorelines.  Saudi Arabia 1521 (2 megawatts) can be heard up to 4 hours 
> pre-sunset in autumn / winter right at the shore in New England and 
> Atlantic Canada, even with modest antennas.  At sites even just 10 miles 
> (16 km) inland, two hours pre-sunset is about as good as you get on 
> similar "compromise" antennas.  Here's a typical Massachusetts coast 
> recording of the 1521 flamethrower:
> " http://www.qsl.net/wa1ion/audio1/dx_saudi_arabia-1521_20060503_2300z.mp3 
> ".  A small car roof mounted loop was all that was necessary.
>
> * The differences between shore and inland are less when efficient 
> full-sized antennas (vertical at least 1/8 wave over a good radial system, 
> or halfwave dipole mounted a quarter wave or higher above the ground 
> directly below it) as contrasted with lower-efficiency / smaller antennas 
> often used for receive (figure-of-8 or cardioid-pickup loops, active 
> whips), especially if those antennas are near the ground.  No surprise 
> there.
>
> * The differences between shore and inland are less when the route is 
> shorter, the path is all dark, and solar activity is low.  New England to 
> UK or Norway in autumn or winter might only show about a 6 dB advantage to 
> a coastal site to a similarly-equipped station inland (meaning, roughly, 
> more than 20 miles of average soil to the nearest salt water on the 
> bearing of interest).  Deep Africans and South Americans heard during 
> auroral conditions, or anything from the Middle East and beyond (> 5000 
> miles) at any time, will show a strong enhancement, at least on smaller 
> antennas, near the shore.  For many years I have been noting what medium 
> wave stations from places such as South Africa, Lesotho, Brazil, and 
> Argentina can do at various sites in Massachusetts.  Up to 2012 I lived in 
> west-suburban locations near Boston.  These are more than 30 miles from 
> the ocean on the southeasterly bearings towards Brazil.  In thousands of 
> hours of listening over more than 50 years I think that four or five 
> Brazilians would be the maximum logged in the 530-1710 kHz range.  Where I 
> am now in South Yarmouth, MA on Cape Cod - about two miles from West 
> Dennis Beach on the range of Brazil-ward bearings - I've logged close to 
> 10 Brazilians in about two years.  My parents' house in West Yarmouth 
> (1974-2001) and my brother-in-law's in East Harwich (1994-2004), also 
> about two miles inland on Brazil bearings, performed similarly to my 
> present QTH.  But the big winner is listening from the car directly sited 
> at beaches with open water to the southeast.  I had more than a dozen 
> Brazilian stations in a single two-hour session at Orleans, MA and, 
> cumulatively, over 20 stations from Brazil in the logbook as a result of 
> various MA beach DXpeditions over the years just using small loop or 
> active whip antennas mounted on the car roof - antennas far inferior to 
> what could be run at various house-based sites.  The station from 
> Fortaleza, Brazil on 760 kHz barely ever registers a peep in the suburbs 
> west of Boston but it's often loud around sunset (after semi-local WVNE 
> power-down) at shore locations such as Tonset Rd. - Orleans, MA (Cape Cod) 
> and Granite Pier - Rockport, MA (Cape Ann).  The shore-vs.-inland 
> difference on that one is easily 25 dB.  This is why, on both coasts of 
> North America, year after year, broadcast-band DXpeditions produce 
> loggings in a single night that the same DXers have not heard from home in 
> a lifetime of listening, sometimes even if using better receivers and 
> antennas.  So many years of different DXers noting the same results take a 
> lot of the statistical uncertainty out of the equation - it just can't be 
> that every time someone went out to the shore the propagation magically 
> went crazy and then went back to dull / normal as soon the DXer was back 
> in his own driveway.  Anyway, that significant shore-versus-inland 
> conditions can exist is borne out by the fact that, on at least some 
> occasions, several DXers were listening at the same time from various 
> sites and noting big differences in strengths and quantity of long-haul 
> loggings.   It used to be difficult to prove things when you had to be on 
> the exact same frequency at the exact same time.  Nowadays DXers are 
> saving the entire spectrum to disk from SDR receivers such as Perseus and 
> Excalibur.  A top-of-hour (prime ID time) +/- 2 minutes band capture from 
> Location A can now very accurately be compared to one made during the same 
> time interval from Location B.
>
> * There are times that, contrary to common intuition, a very long haul 
> route is best covered by antenna that works for high take-off angles. 
> This is typically during greyline transitions and results from 
> reflective-layer tilting / chordal-mode propagation.  During such a 
> condition, my "gut feel" is that there should be very little difference 
> between coastal and inland sites.
>
> * To muddy things up further, inland sites can vary quite a bit too.  Some 
> of the advantage of shore sites may be owing to minimal obstructions as 
> well as to good conductivity.  Obstructions degrade lower-angle signals as 
> well as poor ground conductivity.  An inland "wide open farm" (or grassy 
> marsh area) with a long view to the horizon in the direction of interest 
> is going to outperform a "typical suburban" site with buildings, power 
> lines, and tall trees towards the DX.  An elevated site would outperform 
> normal suburbia for the same reason.  Just as with a shore site, the 
> unobstructed-view inland site is also apt to have less man-made RF / local 
> electrical noise coming in from the desired direction than "average" sites 
> in developed areas.
>
> * If you don't have a coastal site, altitude would be the next-best magic 
> bullet.  This means both in terms of the antenna height above the ground 
> directly below it and the actual surface level relative to surrounding 
> terrain.  A house site that I used in East Harwich, MA was about a mile 
> and a half inland over lossy sandy soil.  Sunset-period transatlantic 
> reception on a small homebrew broadband loop of similar performance to a 
> Wellbrook ALA1530 was evaluated at a nearby shore site (Town Landing near 
> Tar Kiln Road - S. Orleans, MA) and at the house.  Predictably, big 
> stations such as Algeria 549 and Saudi Arabia 1521 came in an hour earlier 
> right at the seashore.  Some of the inland deficiency was removed by 
> relocating the small loop from near-ground-level to about 70 ft. height 
> (via rope over the top of a pitch pine tree).  I'd say that the treetop 
> loop performance came in about halfway between the near-the-ground loop 
> operated at the house and operated at the shore.
>
> The latest crazy aspect of medium-wave DXpeditioning is exploiting TWO 
> magic bullets - seaside PLUS altitude - at the same time.  Gary DeBock 
> (N7EKX) has led the charge on this at the "Rockwork 4" site on the Oregon 
> coast.  See " 
> http://www.antenadx.com.br/?wpdmact=process&did=MjcxLmhvdGxpbms= " for one 
> write-up.  From 2013 we have a DXpedition article starting with 
> "Concurrent with a separate DXpedition in Yachats (OR), from July 21-27 
> another wild ocean cliff DXpedition was conducted from "Rockwork 4," a 
> 400' high sheer cliff located on Highway 101 in Tillamook County, Oregon."
> See " 
> http://www.hard-core-dx.com/article.php?story=20130731111543372&mode=print 
> ".
>
> Sample reception of 603 kHz Radio Waatea in Auckland, New Zealand, 5 kW:
>  " 
> http://www.mediafire.com/listen/u25glqbzfr7e2h3/603-R.Waatea-1253z072213PL380.MP3 
> ".  No one in the USA has heard a signal like that from this station at 
> inland home sites.
>
> Acadia National Park in Maine has similar sites with both salt water 
> proximity and high altitude.  Strong Brazilians on 1100, 1220, 1280, etc. 
> are pretty common stuff at the top of Cadillac Mountain there.
>
> As others have mentioned, you can undo a lot of the "inland disadvantage" 
> by the use of highly-efficient tall verticals over a copious radial field 
> or a horizontal antenna at heights in the half-wavelength or greater 
> range, e.g. 250 ft. at Topband.  Site altitude (mountaintop) or, barring 
> that, wide open level or downsloping farmland free of obstructions will 
> help too.
>
> Sometimes it's all up to the ionosphere.  Of US regions, New England often 
> has the best punch to Europe if only because of shortest distance - 
> coastal vs. inland notwithstanding.  But if the auroral "doughnut" (torus) 
> is too much in the way, Florida will outperform by using open paths south 
> of the auroral zone.  Northern Lakes and Plains states (e.g. Minnesota) 
> might also outdo W1-land by getting through the "doughnut hole." 
> Certainly going US to northern Norway and Sweden this is often the case: 
> the route from MN, ND, etc. over Hudson Bay can frequently beat what's 
> coming from MA, NY, etc. along the Atlantic but heading straight into the 
> jaws of the aurora.
>
> Now that we've analyzed the heck out of shore versus inland, I guess 
> mountaintop versus lowland would be the next thing to discuss.
>
> Mark Connelly, WA1ION
> South Yarmouth, MA
>
>
> <<
> Hi Guys
>
>
> K3ZM is my brother - and his 160m antenna is located in a salt marsh just 
> to the
> West of Chesapeake Bay in Matthews, Va as I recall. Indeed he is located 
> inland
> a bit (eg: not directly at water's edge) - perhaps 1000 feet distant 
> (although
> this is only a guess on my part from photos I have seen).  But the 
> intervening
> land is also primarily salt marsh.  At certain times of the year this land
> floods with salt water and it is necessary to wear very tall boots in 
> order to
> walk out to the base of the towers Peter owns.  I am sure Peter could add 
> more
> specifics.
>
>
> From conversations I have had with Peter over the years - and from 
> listening to
> his signal over at 7O6T, I can tell you that he is very competitive when
> compared to his peers.  Additionally, his ability to hear for a location 
> so far
> South (eg - not in New England) - especially in winter is quite remarkable 
> His
> contest results in 160M contests speak for themselves.
>
>
> Other observations - perhaps relevant, perhaps not.
>
>
> W1WEF and I often get together for lunch in Orleans on Cape Cod.  Jack 
> works the
> HF bands from his mobile CW rig in his car - and when he drives out to the
> peninsula where I live (just off Pleasant bay which is salt water) - dead 
> 15m
> and 20M bands magically go from NO European signals to a full band of 
> signals as
> he comes up the road that runs along the Bay.  He describes it as going 
> from a
> DEAD BAND to a wide open band as he nears my home.  This is in the daytime 
> in
> summer as I recall.
>
>
> Personally here at VY2ZM - I am sure by co-locating my vertical systems at 
> or
> near the water's edge has helped me - to what degree I am not sure - but 
> it is
> rare to be outheard looking NE or East on the lowbands.
>
>
> During this thread I am pretty sure I read a post that co-location near 
> Salt
> water is additive also for horizontal yagis.  I do not believe this to be
> correct.  My good friend Don Toman has several times told me the effect we 
> are
> seeing here is primarily limited to verticals - and not to horizontal 
> yagis -
> which according to Don, rely principally on their height above ground as 
> the key
> variable impacting their performance.
>
>
> On the other hand, shooting out over open ocean from a slightly elevated
> position with HF yagis is a pretty good takeoff to be sure.  Especially 
> when
> compared to looking uphill over land in other directions - which I find 
> causes
> performance to suffer by comparison.
>
>
> FWIW
>
>
> Salt water is good stuff.  Especially for verticals placed at or near the 
> ocean
> - with additional ocean out in front of the antenna for hundreds of miles. 
> I
> too have never fully understood the phenomena but I know it is magical in 
> terms
> of lowband DX'ing performance.
>
>
> 73 JEFF  K1ZM/VY2ZM
>>>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 4007/8049 - Release Date: 08/16/14
>