Topband: New 160M high performance receiving antenna at W3LPL

[donovanf at starpower.net]

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" <k7tjr at msn.com>  
>Subject: New 160M high performance receiving antenna at W3LPL  
>To: "Robert McGwier" <rwmcgwier at gmail.com>, "Frank Donovan" <donovanf at starpower.net>
>Cc: "Topband" <topband at 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
>
>