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Antenna Comparison Randomwire vis Attic Dipole


eladner65
(@eladner65)
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Joined: 2 years ago
Posts: 77
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I have over the last year had 2 antennas up on 20m, and I finally have had a chance to do a comparison of them side by side on WSPR on the same day.  In order to minimize time of day and atmospherics, I switched back and forth between the antennas each 2 minute cycle.

Attic single band 20m dipole, mounted in the peak of my attic fed by some LMR-400, home made 4:1 balun at the feed point.  I estimate this at about 25ft above ground.  My randomwire is a 63ft sloper to a tree, fed at the low south end by a home made 9:1 unun with counterpoise, getting to about 35 feet above ground.  Also fed with LMR-400.

All testing was done on WSPR connected to a Icon 751a with a MFJ-841D manual tuner, and the WSJT-x software on 20m on 9/26/2020

Only stations that were received on both antennas at the same reported wattage within 10 minutes of each other were used in the sample set.

The end result is that my Attic dipole is about -3db for receiving from my randomwire on 20m.  


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AE0CA
(@ae0ca)
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Joined: 2 years ago
Posts: 13
 

Good test Ed. It would be interesting to see if an EFHW would have different characteristics over the random wire.  I'm going to need to run WSPR on my Wolf River Coil.

73,

Robert

AE0CA


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eladner65
(@eladner65)
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Joined: 2 years ago
Posts: 77
Topic starter  

An update.  I’ve done some work to improve my station ground system for the random wire.  Before and after testing show a reduction of background static by 2 s points on 20 and 40m.

I’m hearing much better at night, and about the same during the day on wspr.  Transmission is about the same as it was before.

Ed L.


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