RadioBanter - View Single Post

January 1st 05, 01:14 AM

On Wed, 29 Dec 2004 09:46:57 -0600, (Richard
Harrison) wrote:

The designer likely assumed the loop and the wire would be immersed in
AM and FM fields adequate for satisfactory reception.

The AM loop may not have enough signal because you`ve put it under a
metal roof. The FM wire may not have enough signal because its elevation
is too low at your site. You`re down in the Rio Grande valley.

So, if I took the 'rinky-dink' plastic loop antenna outside and placed
it above the roof, it would work? Do I have to have a pair of wires
for a lead-in or would just one do?

The FM wire is likely about 2.5 feet long, or about 1/4-wavelength. Its
impedance would be about 30 ohms near resonance.

The loop is likely part of the AM tuned input circuit with an impedance
of about 1000 ohms.

For FM, you need to get the antenna up high. A ground-plane antenna is
simple and works well. Vertical and radial parts can all be about 2.5
ft. long. It can be connected to your radio with 50-ohm coax. The
existing wire is your FM input.

I suppose an old car antenna would work for the FM if I placed it up
high, also?

Ground to the radio is probably one of
the "rinky-dinky loop" wires.

I don't see any place to connect a ground.

If not, capacitive coupling via aluminum
foil or the like will likely do.

This I don't understand.

--
The Seabat