"Diverd4777" wrote in message
...
Hi Frank

I bought a Radio Shack Loop antenna a while back
; works pretty well!
- But I need a smaller, lighter A.M antenna for travel;
the smaller & lighter the better;

- hence the ferrite experiment.
Already have a Sony AN-LP-1 works great for SWR

Dan


I see. A box loop still might be workable. They can be made
collapsable or foldable. I saw an antique box loop in which the upper
center support of the X telescoped into the lower center support and the
side supports folded down. Pretty cool, but not so easy to fabricate
with whatever is around the house.

Still, a cardboard form maybe 4 inches wide and 1 foot or so on each
side could be folded into a reasonably compact package. It should
perform about the same as the RS loop. Or a piece of cardboard could be
cut for a spiderweb winding. Just cut an odd number of notches about
1 -2 inches deep, spaced about 2-4 inches apart around the perimiter of
a piece of cardboard. Maybe 8 or 10 turns, depending on your cap - but
add a few more turns, so you can tune it in.

A plastic dielectric cap is smaller and less fragile than a air
dielectric cap and will be better for portable use. You don't need to
spend alot of time trying to figure out which are the AM oscillator or
AM antenna or the FM parts of the capacitor. Just figure out which are
the common lugs and the cap lugs. You can wire up the all AM and FM
lugs together for more total capacity. The higher total capacity will
mean you need fewer turns for your antenna. Be sure to open all the
half moon trimmers so you get the widest capacity range.

Frank Dresser