AM Loop Antenna Model #1
Necessity is most definitely the mother of invention. I needed an antenna for all my old AM radios and
did not wish to run an outdoor antenna. So this is my version of a Marconi loop antenna. I wanted
something that would also look nice and be period correct in it's appearance. It turned out really nice
and works really well. It was made from some 60 year old 7/8" thick solid cherry. The center hub inlay
is Black walnut (my first attempt at inlay work) and the F is hand painted. The entire antenna is
finished only in tung oil. Except for the 100 or so holes in this antenna the rest was all by hand. Both
my arms and the drill press are now worn out. The antenna loop is 67 feet of brown cloth covered 20
gauge stranded wire. In the base there is a 365 pico farad variable capacitor. On the bottom is a 6 way
barrier block which allows the antenna to be wired many different ways. It can be wired with or without
the internal variable capacitor, and other mica capacitors can easily be added. The lead in antenna wire is
9 feet long making the antenna 75 feet in legnth. The ground wire is 10 feet long, and the variable capacitor
is wired in pararlel in the antenna circuit. The capacitor is adjusted by a walnut knob on the base. The
spacing between the wires is 1/2" and it starts at the hub. Overall the antenna is 32" tall, 26" wide,
the base is 9" X 6" X 1-3/4" thick. It weighs in at 6 Lbs. If I ever take the time to caluculate its
Henry value i'll post it here.......
When fall gets here i'll post some better pictures, it is sweet in the sunshine. Between planning and
building this antenna I have a couple of hundred hours in it. It was a lot of fun to make.