[Skimmertalk] Another Skimmer Antenna Idea
N4ZR
n4zr at comcast.net
Tue Jan 16 22:46:27 EST 2018
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.
--
73, Pete N4ZR
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