Hello all, this is my first post here, and I hope I won't violate any rules !!
Since I discovered the KK5JY LoG design (
The Loop on Ground Antenna - the "LoG") years ago and after building several samples of the antenna and fiddling with it, all I can say is that I felt in love with such a simple, invisible, cheap antenna; I'm not saying it's the best antenna you can use for RX, but if one is plagued by noise (switching mode stuff, plasma TV sets and then some), the LoG may really do miracles; what it won't do will be boosting signals, the LoG is all about S/N ratio, what it will do is lowering your overall noise floor and allowing to pick up signals which would, otherwise, be lost into the noise
That said, while the LoG is simple to put together, in my experience it's somewhat "picky" about how and where one installs it, what I mean is that the LoG must be ON ground (not raised) and that it should be laid down in a spot where there aren't underground metallic objects, be those pipes, wires, old tanks or whatever, since those would almost totally ruin the antenna performance, also, ensure to feed the antenna using a transformer built exactly as shown on Matt's (KK5JY) page, do not feed it directly with coax or use a different BalUn design (that may, and in my own explerience, will, ruin performances) and, if possible, add a good CM choke right after the BalUn, not mandatory, but will help; if then the antenna performance isn't still satisfactory, try moving the wire to reorient/move the antenna to a different location, that will help in case there are underground/nearby metallic objects, also, to keep the LoG wire on ground do not use metallic stakes, use plastic ones or, either, bricks or the like
Also, while the LoG doesn't usually need a preamp (as long as one feeds it using decently low loss coax), in some cases one may want to add a preamp to boost the received signals (but remember that it will also raise the noise floor); in such a case there are two preamplifiers which I tried with the LoG and which work pretty well
The first one is a very simple, yet good preamp designed by W7IUV, the preamp is a wideband one and works well on the "top bands" (up to about 7Mhz), its schematic can be found here
https://www.okdxf.eu/files/preamp_r60.pdf - a different approach which I also tested, was using a tuned preamp (instead of a wideband one like the previous), the preamp I tested is described here
http://www.arrl.org/files/file/QEX_Next_Issue/Jan-Feb2018/Steber.pdf it's a tuned preamp using a varactor stage, if going for such a preamp, build it so that the tuning/power unit will sit in the shack, while the preamp will be at the antenna feedpoint (between the balun and the choke) and will be powered/controlled using a run of (e.g.) CAT-5 cable (RF will still go through the coax), in such a case, add a bypass relay to the preamp so that, flipping off the power switch on the (shack) control box will open the relay, bypassing the preamp and allowing to use the LoG in passive mode
But again, before going for the preamp, try properly laying down the LoG and if needed moving it to a different location, also, when testing it, ignore the "S meter", as I wrote, this antenna isn't about boosting signals, but about lowering the noise so that, even if weak, signals will become readable
