[BC] AM loop receiving antennas

[Dana Puopolo]

You can make your own loop easily enough. Take a 10 foot piece of conduit and
carefully bend it into a loop. Run two pieces of cat 5 in the loop. Connect
the pairs (not the single wires) together so they total out 8 turns.

Now you have to resonate the loop. Beg borrow or steal a function generator.
Set its frequency to the desired one and its output to a sine wave and turn it
all the way up. Connect it to the loop with a 10 k (or higher) resistor.
Ground one side of the loop only. Connect a scope across the loop. Now add
small mica capacitors across the loop until you peak the waveform on the scope
(your total capacitor will likely be lass then 1000 pf).
Make the circuit weatherproof and feed the loop with coax (RG6 is good).

This loop with perform as well as ones costing hundreds of dollars.

-D

From: "Bruce Doerle" <bdoerle at mail.ucf.edu>

Check out the Belar AM loop antennas, they make for both passive and active
systems.  Broadcaster's General Store can order them.  They can be a bit
pricy, but they are good.  At least three stations here in Orlando use them
for EAS reception.  I can tell you, it overcame the building noise problems
that I was having.