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Thursday, September 28, 2023

Faraday Cloth

 First, the QRP Image of the Day


Courtesy of I5NOC (on Facebook) - reminded me of the Four State QRP Group Bayou Jumper, of which I have one in the basement, needing to be built. Ahhhhh .... retirement can't come quickly enough!

So the latest rage amongst POTA activators and other portable ops QRPers, who use compact verticals, is to place a piece of aluminum window screen under the antenna, instead of laying out conventional radials. You still have to run a wire from the screen to the ground connection of the antenna system, but altogether this sounds like a convenient workaround compared to laying out radials. And from some testimonials that I have read on the various QRP e-mail reflectors and from some of the QRP groups on Facebook, it seems like it gets "a thumbs up".

Back in the day when I used to use a homebrewed PAC-12 antenna, I did lay out radials, which in itself was not a big deal. The inconvenience arose when you were in a setting like a park or some other public place where people could trip over the wires. It was even worse if you elevated the radials. 

Now the latest, latest rage seems to be substituting Faraday cloth (cloth imbedded with or made from copper and nickel) for the groundplane. It seems that folding up this cloth and storing it is an easier deal than aluminum screening. The cloth is very flexible and can be folded up into a neat little size which can be stowed away in your go-kit. The aluminum window screen, on the other hand, really should be rolled up.  I don't think it would take to well to repeated folding and unfolding - metal fatigue can be a nasty thing.

When I use my Buddistick, my modus operandi has been to use the roof of my Jeep as the groundplane, planting the antenna on the metal with a magmount.  That setup has worked very, very well for me. But this Faraday cloth setup is intriguing to me. It would allow me to use the Buddistick away from the car, which might come in handy when there are no trees for a wire, or the use of trees (like in a park) is prohibited. That's when I would normally resort to the magloop.

I may have to try this. I see that on Amazon, you can purchase a piece that is 44" X 36" (112cm X  92cm) for only $23. That should be big enough to provide a decent groundplane.

And it just so happens that a great illustrative photo appeared on Facebook today. This was taken by Dan Hones KD9MSP on a recent POTA activation that he made.



72 de Larry W2LJ
QRP - When you care to send the very least!

2 comments:

  1. Anonymous7:28 AM

    How did it work for 40m? (I may have to try this. I see that on Amazon, you can purchase a piece that is 44" X 36" (112cm X 92cm) for only $23. That should be big enough to provide a decent groundplane.)

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  2. Hmmm, very interesting. I just found the same 44x36" sheet on the UK Amazon and very nearly bought it, but something held me back. I guess I'm not totally convinced how effective it would actually be, so I'll wait for a decent review of the application to be published.

    Are you going to try one Larry??

    73, Tom, M7MCQ
    www.m7mcq.com

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