Topband: New 160M high performance receiving antenna at W3LPL

[Lee K7TJR]

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