[Norman]

Hi,
I have 2 similar table model FM radios, with similar reception problems. I
connected a homemade folded dipole (made of twin lead) to the 300 ohm
antenna terminals of one and had good results. The other radio has only a
short length of wire as the FM antenna. I tried to increase the length
somewhat but there was no appreciable change. I would like to connect a
folded dipole to it but since it now has only the single wire antenna, no
300 ohm terminals, where would I connect the 2 dipole wires?

[Gary A. Edelstein]

On Tue, 22 Aug 2006 12:50:52 -0400, Norman
wrote:

Hi,
I have 2 similar table model FM radios, with similar reception problems. I
connected a homemade folded dipole (made of twin lead) to the 300 ohm
antenna terminals of one and had good results. The other radio has only a
short length of wire as the FM antenna. I tried to increase the length
somewhat but there was no appreciable change. I would like to connect a
folded dipole to it but since it now has only the single wire antenna, no
300 ohm terminals, where would I connect the 2 dipole wires?

The wire is probably 75 ohm. Try a 75 to 300 ohm transformer and hook
the wire up to the center connector on the 75 ohm side and the dipole
to the 300 ohm side.

Here's one at Radio Shack that happens to be a splitter too; I believe
they have others.

http://www.radioshack.com/product/in...ductId=2062053

Gary E
--
|Gary A. Edelstein
(remove NO SPAM and .invalid to reply)
|"We have met the enemy and he is us." - Walt Kelly's Pogo

[GregS]

In article , Gary A. Edelstein wrote:
On Tue, 22 Aug 2006 12:50:52 -0400, Norman
wrote:

Hi,
I have 2 similar table model FM radios, with similar reception problems. I
connected a homemade folded dipole (made of twin lead) to the 300 ohm
antenna terminals of one and had good results. The other radio has only a
short length of wire as the FM antenna. I tried to increase the length
somewhat but there was no appreciable change. I would like to connect a
folded dipole to it but since it now has only the single wire antenna, no
300 ohm terminals, where would I connect the 2 dipole wires?

The wire is probably 75 ohm. Try a 75 to 300 ohm transformer and hook
the wire up to the center connector on the 75 ohm side and the dipole
to the 300 ohm side.

Here's one at Radio Shack that happens to be a splitter too; I believe
they have others.

http://www.radioshack.com/product/in...ductId=2062053

Since the only thing comming out of the radio is a wire, connecting
the other side of the balun is going to be a problem unless one opens
up the radio and figures out what to do,

About 30 inches is the optimum 1/4 wavelength.

greg

[isw]

In article ,
Gary A. Edelstein wrote:

On Tue, 22 Aug 2006 12:50:52 -0400, Norman
wrote:

Hi,
I have 2 similar table model FM radios, with similar reception problems. I
connected a homemade folded dipole (made of twin lead) to the 300 ohm
antenna terminals of one and had good results. The other radio has only a
short length of wire as the FM antenna. I tried to increase the length
somewhat but there was no appreciable change. I would like to connect a
folded dipole to it but since it now has only the single wire antenna, no
300 ohm terminals, where would I connect the 2 dipole wires?

The wire is probably 75 ohm.

Actually, probably not; it's probably a high-impedance input. Those can
work quite well with a "short" antenna, something a 75 ohm input cannot
do. The difference lies in whether the input of the receiver wants
signal power (matched impedance), or just signal voltage (high
impedance).

Oddly enough, if the input impedance is "infinite", the signal voltage
(not power) picked up by the antenna is independent of its length.

Isaac