There is a wullenweber antenna down in the San Diego area - south end of the Coronado peninsula....not operational but the site is used by the Navy Seals.
Jim R. K9JWV > Date: Mon, 4 Feb 2013 23:27:42 -0800 > From: charle...@msn.com > To: topband@contesting.com > Subject: Re: Topband: New 160M high performance receiving antenna at W3LPL > > Much much closer to home for us Pacific NW'ers: > > https://maps.google.com/maps?q=40+43+24+n,+141+19+44+e&hl=en&ll=40.72308,141.328892&spn=0.003313,0.006968&sll=40.723876,141.329155&sspn=0.026507,0.055747&t=k&z=18 > > It looks to be operational and is still gated and guarded and has cars > parked at the building. > > > Chuck > > > On 2/4/2013 10:53 AM, donov...@starpower.net wrote: > > Hi Lee, > > > > You can save yourself lots of engineering effort if you simply make > > yourself a copy of this one: > > > > https://maps.google.com/maps?q=40+43+24+n,+141+19+44+e&hl=en&ll=40.72308,141.328892&spn=0.003313,0.006968&sll=40.723876,141.329155&sspn=0.026507,0.055747&t=k&z=18 > > > > My former employer (then Sylvania, now General Dynamics Advanced > > Information Systems) installed it in 1966 at Misawa Air Base, Japan. I > > believe its still exists, but its probably no longer in use due to > > technical obsolesence, high maintenance costs and unavailability of spare > > parts. An identical array installed at Elmendorf Air Base, Alaska is also > > still in existence as far as I know. Maybe you can purchase one of them! > > > > Many copies of the original 40 element German "Wullenwever" array were > > built all over USSR shortly after World War II, some may still exist. > > Among other things, they tracked the 10 and 20 MHz Sputnik beacons that > > some of us recall. > > > > 73 > > Frank > > W3LPL > > > > ---- Original message ---- > >> Date: Mon, 4 Feb 2013 10:13:55 -0800 > >> From: "Lee K7TJR" <k7...@msn.com> > >> Subject: New 160M high performance receiving antenna at W3LPL > >> To: "Robert McGwier" <rwmcgw...@gmail.com>, "Frank Donovan" > >> <donov...@starpower.net> > >> Cc: "Topband" <topband@contesting.com> > >> > >> Hello Bob and all, Yes I agree on the issue of needing the > >> stable impedance > >> from the elements to drive the passive systems. I still have > >> some questions > >> in my mind about the radials and here is why. I have made > >> many field tests > >> where I measured the actual phase and amplitude differences > >> between two > >> receiving elements where one is held constant and parameters > >> around the > >> other were changed such as ground rods, radials, and such. > >> Both were > >> receiving signal from an equidistant transmitted source. > >> What I can tell you > >> for sure about this is that with a Hi-Z system the phase and > >> amplitude shifts > >> become quite unstable when radials are used. I do not know > >> this to be a > >> fact with loaded elements but I have seen evidence of some > >> received > >> signal shift due to the presence of the radials to the > >> element. This test really > >> opened my eyes about received signals and what objects might > >> affect > >> them. I have plans to buy the NEC4 engine and do some more > >> field tests > >> using another technology that should give me more answers. It > >> is these > >> minute details that prevent us from making these RX antennas > >> even smaller. > >> There is no doubt that the state of the art is advancing in > >> receiving antenas > >> with all the work that is and has gone on. I am confident > >> that what we are > >> presently doing is not perfect and I expect the state of the > >> art still has a ways > >> to go. There have been many man years of work by many people. > >> I hesitate > >> to name calls but a few notables are K6SE, W7IUV, W8JI, K9AY, > >> W3LPL, > >> W5ZN, W1FV, NX4D, N4IS, AA7J, K1LT and many many others that > >> I > >> apologize for not having the space here or personal memory at > >> the moment > >> to mention. There are more man years of work to do. > >> I still covet the 96 element Wullenwever antenna invented > >> around 1940! > >> Lee K7TJR > >> > >> >The issue is getting sufficient ground radials so that > >> changing soil conditions: dry season, wet season, etc have > >> minimal impact on the impedance which is the easiest > >> measurement of the changing conditions. Joel and I did > >> measurements several times and when he was near drought he > >> found he had to add radials to stabilize the performance. > >> Once done, his system has been stable since. > >> Great news on both of you successfully deploying. > >> Bob > >> >N4HY > >> > >> > > _________________ > > Topband Reflector > > > > > > _________________ > Topband Reflector _________________ Topband Reflector