Richard Clark wrote in message . ..
On 22 Aug 2004 10:01:17 GMT, ( Doug Goncz ) wrote:

OK, I've got it.

ftp://users.aol.com/DGoncz/Antenna/

WHFS in stereo at 3 AM.

I note the plug has to be in just more than half way, not all the way for best
results. Maybe I should be using a balun, coax, and a phone jack adapter as
suggested.

Yes, very much if things are this touchy. You are trying to feed a
high Z antenna into a low Z cable. Radio Shack has a very common
BalUn product designed to take care of this very simply (and using
common coaxial products they sell too).


No active amplification is used.

That's fine, but by all of your accounts, you are on the thin edge.

For now, primary Teri can live with this.

Hi Doug,

Teri may be able to get along with it much more, if you realized you
have two antennas in one and simply remove one of them. Simple, is
easier said than simple.

By all appearances you have a combination FM-TV antenna as I see at
least 5 elements (you don't show the entire antenna by the way) and
you are only using 3 of them. Your connection should be at the end
that is pointing (east) at the station you want to hear. If it is
not, you have it pointed backwards and this may explain why things are
so hinky. Another clue that you can verify. There should be another
set of antenna connections (like wing nuts that presently you connect
to) at the OPPOSITE end of the boom - n'est pas? They should be on
the next to last elements before the end of the boom.

73's
Richard Clark, KB7QHC

Dear Richard,

You (Richard Clark ) wrote in message . ..
On 22 Aug 2004 10:01:17 GMT, ( Doug Goncz ) wrote:

OK, I've got it.

ftp://users.aol.com/DGoncz/Antenna/

WHFS in stereo at 3 AM.

I note the plug has to be in just more than half way, not all the way for best
results. Maybe I should be using a balun, coax, and a phone jack adapter as
suggested.

Yes, very much if things are this touchy. You are trying to feed a
high Z antenna into a low Z cable. Radio Shack has a very common
BalUn product designed to take care of this very simply (and using
common coaxial products they sell too).


No active amplification is used.

That's fine, but by all of your accounts, you are on the thin edge.

For now, primary Teri can live with this.

Hi Doug,

Teri may be able to get along with it much more, if you realized you
have two antennas in one and simply remove one of them. Simple, is
easier said than simple.

By all appearances you have a combination FM-TV antenna as I see at
least 5 elements (you don't show the entire antenna by the way) and
you are only using 3 of them. Your connection should be at the end
that is pointing (east) at the station you want to hear. If it is
not, you have it pointed backwards and this may explain why things are
so hinky. Another clue that you can verify. There should be another
set of antenna connections (like wing nuts that presently you connect
to) at the OPPOSITE end of the boom - n'est pas? They should be on
the next to last elements before the end of the boom.

73's
Richard Clark, KB7QHC


Oh, dear. I opened

ftp://users.aol.com/DGoncz/Antenna/

to add to my post, closed the window, and lost the post.

Rewrite:

The antenna, a Radio Shack 15-2163 6-Element Triple Drive Outdoor FM
Antenna, is an open dipole having a characterstic impedance near that
of the twinaxial cable. That's how I selected the cable. I matched the
inner conductors and insulation to those of the flexible open dipole
supplied by the OEM. The twinaxial cable has slightly thicker
conductors, but the insulation on both is polyethylene, not PVC, and
the spacing is similar.

The connection is indeed at the east end.

The lead hangs straight down now, and is lashed to a coat hanger wire
narrow V that steadies the antenna side to side, preventing contact
with the ceiling. The weight of the cable steadies the antenna. I
propose a length of chain to lower the antenna to above head height to
get it below the upper sill, and weights to level and balance it. That
way it will rotate left and right a total of 360 degrees for testing,
although it will only have one stable position. The cup hook in the
ceiling appear secure. I have a plastic screw shield to improve the
cup hook mount. It's in there with wooden splints now. Not bad, but
not a hard mount.

The cable is under the rug now, avoiding another trip, which damaged
the phone plug. A 5C collet and closer will straighten the plug. A cat
toy house protects the cable at the transition to the floor. Tasha
likes to curl up in there. They both bat the cable once in a while.

Yours,

Doug Goncz
Replikon Research
Seven Corners, VA

On 25 Aug 2004 02:54:24 -0700, (Doug Goncz) wrote:

The antenna, a Radio Shack 15-2163 6-Element Triple Drive Outdoor FM
Antenna

Hi Doug,

I see nothing of twinax at all.

consult:
http://www.radioshack.com/images/Pro...OME15-2163.pdf

However, you seem to have come to a working arrangement, twinax
doesn't make all that much difference, and it is pointed in the right
direction. I'm sure you are enjoying the music.

73's
Richard Clark, KB7QHC

Dear Richard,

The Radio Shack manual linked below, which I have, and came with the
antenna, doesn't mention twiaxial cable because no twinaxial cable
with an impedance of 75 ohms is available at a reasonable price, so
people use 75 ohm cable because it's cheaper. If I could get 75 ohm
twinaxial cable I'd use it.

The impedance of this and every open dipole antenna is around 75 ohms,
one quarter of the impedance of a 300 ohm folded dipole, just about
ten percent from the impedance of empty space. We are in an
atmosphere....

However, the OEM antenna is a flexible _open_ dipole with a
characterstic impedance of 75 ohms. I think 100 ohm twinax is a good
choice.

Can any readers source 75 ohm twinax?

Doug

Richard Clark wrote in message . ..
On 25 Aug 2004 02:54:24 -0700, (Doug Goncz) wrote:

The antenna, a Radio Shack 15-2163 6-Element Triple Drive Outdoor FM
Antenna

Hi Doug,

I see nothing of twinax at all.

consult:
http://www.radioshack.com/images/Pro...OME15-2163.pdf

However, you seem to have come to a working arrangement, twinax
doesn't make all that much difference, and it is pointed in the right
direction. I'm sure you are enjoying the music.

73's
Richard Clark, KB7QHC