This article is a reprint from my original article published in 2004. I don’t use the antenna anymore (collecting dust in the basement) but the article will stay here for informational purposes.
I live in an appartment and don’t have the space to put up a large antenna for my Kenwood R1000 receiver.
I knew the excistance of magnetic loops, but I never spent time to take a look at it. Why ? Who knows.
For the main loop I used a soft copper tube, diameter is 10 mm, length about 3 meter.
Try to make a circle (not always easy). A friend of me, Carl ON7NH, has drilled and tapped M3 tread into it. This makes it possible to use solder lips. The entire loop is constructed on a sunday afternoon.
The smaller loop is about 60 cm in length (diameter 1/5 of the main loop), material is 1,5 square mm copperwire.
With the capacitor found in my junkbox, I can tune the loop from 2,9 Mhz till 10 Mhz. Other capacitors will give other tuning ranges, have to experiment here.
Steve Yates, AA5TB, has some nice info on this subject.
KR1ST has a nice building description, wich I followed.