[Lowfer] Loop antenna question

[John Bruce McCreath]

WOW….never expected that my query would result in so many responses,
so thank you to all who replied.  I’ll now explain what prompted me to ask
the question in the first place.

Many years ago I erected a vertical, square loop, of 25 feet per side, that is
suspended between two of my towers, intended for the new 30 metre band.
The feed is at a bottom corner where a 1:1 current balun connects to the
RG-6 feed line.  The bottom of the loop is about ten feet above ground,
and it is oriented roughly east-west.

Several months ago, I tried using it for reception of Navtex transmissions
on 518 kHz. with a G3XBM design grounded-gate FET preamp and found
that it worked just as well as my usual PA0RDT mini whip.  It appeared to
have no directional properties, pulling in all the usuals from all directions
of the compass!

About a week ago, I decided to set up a SID detector, using the excellent
app Spectrum Lab as a VLF receiver and signal plotter.  It’s configured to
watch a slice of spectrum from 19 to 25 kHz.  Not having an antenna for
VLF, I thought I’d try the loop “down there”, and was pleasantly surprised
to find that it worked quite well.

I get good plots from NAA in Cutler, Maine, on 24 kHz. There are several
other stations as well, HWU on 20.9 kHz. from France, and NPM on 21.4
kHz., from Hawaii, but they are not always copied here.

73, J.B., VE3EAR

LowFER Beacon "EAR"
188.831 kHz. QRSS30
EN93dr