I have been interested in magnetic loop antennas (or Small Transmitting Loops (STL)) for some time but never owned or used one. I looked at purchasing one of these to get me on HF from the home location due to now having a much smaller garden but as they are rather expensive I decided to do a bit more reading up on them.
Ideally I want the antenna to be installed in the roof space. I have also been watching Ebay for used MFJ antennas as these have the power handling and cover the bands that I want to operate on. Everything looked fine and I saw a couple with some low starting prices on. However when I checked the specification of these antennas I found that the tube used to form the loop was a continous piece which was no good for myself as the loop would be 30cm too big in diameter to pass through the access hatch in to the roof space. It was at this point I decided to build my own.
If you search on the internet for information on magnetic loop antennas you will be spoilt for choice as there is so much. I will list just a few sites that I have found useful in time I have been experimenting with mag loops.
I have only used two programs for loop calculations, the AA5TB calculator and G4FGQ's RJELOOP1. Theycan be downloaded from the links below.
aa5tb_loop_v1.22a.xls - Microsoft Excel Application (62kB)
RJELOOP1.EXE - Go to software downloads and download RJELOOP1 Performance of Transceiving, single-turn, magloop antennas of various regular shapes.
The pages on magnetic loop antennas will be a "work in progress" so initially I will link to information on the antenna I am currently working on and when possible links to other experimental loops I have made.
Page updated 31/07/13