[Skimmertalk] Another Skimmer Antenna Idea

[N4ZR]

Little did I realize that this was a well-known design.  There seems to 
be some controversy about it, with some people alleging that it is 
actually relying on common mode cuirrents on the feedline as the actual 
"antenna."  I wasn't aware that PA0RDT offered complete antennas, 
because the web page I saw only offered PC boards and I didn't want to 
do all the packaging.

Whatever the case ... I have run some tests comparing it with a Carolina 
Windom, currently my only "real" antenna.  It is clearly less sensitive 
than the CW, but the SNR appears to be about the same.

73, Pete N4ZR
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On 1/16/2018 10:46 PM, N4ZR wrote:
> Recently, I stumbled across an inexpensive active antenna kit offered 
> by a Ukrainian ham 
> <https://www.ebay.com/itm/MiniWhip-Active-Antenna-Assembled-in-Box-HF-LF-VLF-mini-whip-sdr-RX-portable-/222469570201> 
> He acknowledges that it is based on a design by a PA0, but that's 
> between them.  Anyhow, it is a cute little package (photo at the 
> link), with the antenna proper housed in a 6-inch plastic housing 
> about 2 inches in diameter.
>
> My thought was to use this for the RBN's gap-filling program, since 
> shipping an 8-foot whip is a royal pain, and I assumed you would 
> attach a wire antenna to the top.  Imagine my surprise to discover 
> that the antenna is completely inside the small plastic package.  I 
> don't pretend to understand the  theory of the thing - something 
> called an E-field probe, I gather - but the only antenna in it is a 
> roughly 1.5 x 2.5 inch section of the PC board at the top end.
>
> Humph, I thought - how can this work?  Well, it does, and very well - 
> as I write this my QS1R is happily copying stations on 160, 80 and 40 
> meters with signal-to-noise ratios at least as good as my Clifton Labs 
> whip, my standard of comparison for years. Earlier today, I compared 
> sensitivity and noise on 40-10 meters, and was pleasantly surprised.  
> My methodology was pretty crude - SDRMAXV and a Mark 1 eyeball - but 
> the two antennas appear to be within 5 dB at most, with the advantage 
> on 20M and above going to the "MiniWhip".
>
> I think this first copy of the antenna is going to find its way to 
> EL-land, soon.  Stay tuned.
>