Jeff L wrote:
I made 3 of these antennas many years ago - 10m,15m and 20m - and use
them almost daily. They are modified Radio Shack 5/8 wave base-loaded.
They work very well, and are only about 2 feet tall. It involved
re-wiring just the coil. I use a trunk-lip mount, but they also work
with a magnetic mount. I don't have the article anymore, but I believe
it was in QST (maybe around the mid-80's) .

Thanks Jeff! I'm pretty sure the article I was thinking of did not
come from QST. Seib, VE3JUA found and sent to me an article from 73,
Sept 91, pp. 26-28 titled "Economical Mobile HF Antenna" which is
probably the one I remembered.

I'd also like to find a copy of the QST article. I used to have a
complete collection of QST back to the 70's but that went away too, I
just couldn't continue to store all my old magazines. The ARRL website
allows a search for articles, but in most cases the article text can't
be retrieved. I found a number of possibilities, but I can't tell from
the titles if one of them is really the one you mentioned. If anyone on
the list can help to pin this down I'd appreciate it. At this point
it's not so much for the sake of the information, but just to be able
to properly give credit in an article I may write about some of my own
mobile antenna experiments.

Both the 73 article and the QST article you refer to mention modifying
new antennas from Radio Shack, in one case a CB antenna and in the
other case a 5/8 wave 2 meter antenna. Both of these types of antenna
typically use a coaxial base with a tapped loading coil, and so either
is a good starting point for a modification project. However, for me
the attractiveness of the technique is that it can also be used with
used CB antennas that can be found for just a dollar or two at
neighborhood tag sales. They are not as easy to find as they used to
be, but I'm sure there are still a lot of them in garages and attics.

"Al, N1AW" wrote in message
ups.com...
Jeff L wrote:
I made 3 of these antennas many years ago - 10m,15m and 20m - and use
them almost daily. They are modified Radio Shack 5/8 wave base-loaded.
They work very well, and are only about 2 feet tall. It involved
re-wiring just the coil. I use a trunk-lip mount, but they also work
with a magnetic mount. I don't have the article anymore, but I believe
it was in QST (maybe around the mid-80's) .

Thanks Jeff! I'm pretty sure the article I was thinking of did not
come from QST. Seib, VE3JUA found and sent to me an article from 73,
Sept 91, pp. 26-28 titled "Economical Mobile HF Antenna" which is
probably the one I remembered.

I'd also like to find a copy of the QST article. I used to have a
complete collection of QST back to the 70's but that went away too, I
just couldn't continue to store all my old magazines. The ARRL website
allows a search for articles, but in most cases the article text can't
be retrieved. I found a number of possibilities, but I can't tell from
the titles if one of them is really the one you mentioned. If anyone on
the list can help to pin this down I'd appreciate it. At this point
it's not so much for the sake of the information, but just to be able
to properly give credit in an article I may write about some of my own
mobile antenna experiments.

Both the 73 article and the QST article you refer to mention modifying
new antennas from Radio Shack, in one case a CB antenna and in the
other case a 5/8 wave 2 meter antenna. Both of these types of antenna
typically use a coaxial base with a tapped loading coil, and so either
is a good starting point for a modification project. However, for me
the attractiveness of the technique is that it can also be used with
used CB antennas that can be found for just a dollar or two at
neighborhood tag sales. They are not as easy to find as they used to
be, but I'm sure there are still a lot of them in garages and attics.


The best antennas for these modifications were the Antenna Specialists
loading coils (about 2 to 3 inches tall) Motorola also sold these under
their brand name for a few years.
The ASPS177 was that typical model.
http://wildcard.pctel.com/images_pro...sp553_p473.pdf

You can also find these surplus as many public services are moving to higher
frequencies (and away from 150 -172) in some areas. I also find ones with
broken whips, etc. The whip replacements (K41 for this model) are available
from either Tower Electronics or Antenna Specialists (PCTEL company).
http://www.antenna.com/product_overv...0459&styleid=6

w9gb

another take on modified antennas ...

I have a magmount dual-bander on the roof of my mini van. It terminates in
a BNC for use on an HT.

The stock AM/FM car radio antenna went bad with an open shield and it was
picking up lots of noise. I pulled the radio far enough out of the dash to
unplug the bad antenna. I plugged in a Moto-to-BNC adapter and dropped a
short piece a piece of RG-58 down to where I could mate it with the mag
mount's cable connector. Works great. Quick disconnect BNC lets me go back
and forth as necessary.

BONUS: For our regular trips across the desert, I have an extra-long whip
element that I substitute in the magmount base. I lose the match at 440 but
it still works like a champ for 2M or AM/FM, my choice.

I have not played with diplexing as swapping connectors seems too easy.
Yeah, a switch maybe ... someday.