[Skimmertalk] Another Skimmer Antenna Idea

[David Gilbert]

Pretty much any linear conductor is an e-field probe.   That's what most 
antennas are.  This one is simply very short, and it even looks like it 
has a large plate at the end to provide some capacitive loading.

By the way, here's the web site of the PA0 who did the original design.  
He doesn't sound very happy about the Ukrainian offering and seems to 
question whether the Ukrainian version has the same dynamic range of his 
design.

http://www.pa0nhc.nl/Miniwhip/indexE.htm

Dave   AB7E


On 1/16/2018 8:46 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.
>