Topband: New 160M high performance receiving antenna at W3LPL

[Gary K9GS]

This topic made me curious to see what was on Google Maps:

http://maps.google.com/maps?q=40%C2%B02'57%22N+88%C2%B022'50%22W&ie=UTF8&ll=40.049563,-88.380675&spn=0.01636,0.038409&hnear=0x880ccc1bf72e2559:0x257eb5f56359d600,%2B40%C2%B0+2'+56.91%22,+-88%C2%B0+23'+15.98%22&gl=us&t=h&z=15

(may have to do some cut and pasting of the link.

Looks like not much left although the "circle" is still well defined for 
some reason.



On 2/5/2013 8:35 PM, Gary K9GS wrote:
> Or there's this one in Champaign, IL at the University of Illinois.
>
> http://www.ece.illinois.edu/about/history/wullenweber/index.asp
>
> It's been several decades since I've been out there and up close. In the
> early 80s it was already in considerable dis-repair.
>
>
> On 2/4/2013 12:53 PM, donovanf at 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" <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
>>>
>>>
>> _________________
>> Topband Reflector
>>
>

-- 


73,

Gary K9GS

Greater Milwaukee DX Association: http://www.gmdxa.org
Society of Midwest Contesters: http://www.w9smc.com
CW Ops #1032   http://www.cwops.org

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