On Nov 11, 11:42*am, John Ferrell wrote:
On Wed, 10 Nov 2010 13:46:12 -0800 (PST), JIMMIE

wrote:
On Nov 7, 4:18*pm, Owen Duffy wrote:
"David" nospam@nospam wrote :

Which antenna is better: 5/8 wavelength vertical or a J pole?

Better for what? For example, a 5/8 whip would usually be better than a J

snip



Owen, I think the popularity of VHF mobile 5/8 antenna lies in it has
more gain than a 1/4 wl antenna and is easier to match to 50 ohms than
a .5 wl antenna. I had certainly rather DIY a 2M 5/8 mobile antenna
than a .5 wl version. From information I have seen the 5/8 often
touted for its low angle of radiation may actually have a
significantly higher angle of radiation than the .5 wl antenna used in
a similar situation. This is not to say either antenna would not be
equally useful.

Jimmie

In the late 1970's my work car was a tiny Ford Fiesta (AKA "Fiasco"
It was fitted with a 5/8 wave on a fender mount. The transciever was a
Heath 2036 at 5 watts. The antenna did perform very well as far as
distance was concerned.

However, it was tall enough to ping the light fixtures in the many
parking garages that were essential to my job.

The biggest advantage of a J-Pole is that it is not dependent on a
good ground.

John Ferrell W8CCW

I ve had both .5 and .64 wl antennas on my big Chevy Van. I cant tell
any significant difference in performance except for a couple of .5
antennas that were really poor performers, I think this may have been
due to matching network design.. Except for this cause I dont see how
there could be any perceptable difference in the two antennas short of
careful measurements on an antenna range..


Jimmie

On Thu, 11 Nov 2010 14:08:39 -0800 (PST), JIMMIE
wrote:


In the late 1970's my work car was a tiny Ford Fiesta (AKA "Fiasco"
It was fitted with a 5/8 wave on a fender mount. The transciever was a
Heath 2036 at 5 watts. The antenna did perform very well as far as
distance was concerned.

However, it was tall enough to ping the light fixtures in the many
parking garages that were essential to my job.

The biggest advantage of a J-Pole is that it is not dependent on a
good ground.

John Ferrell W8CCW

I ve had both .5 and .64 wl antennas on my big Chevy Van. I cant tell
any significant difference in performance except for a couple of .5
antennas that were really poor performers, I think this may have been
due to matching network design.. Except for this cause I dont see how
there could be any perceptable difference in the two antennas short of
careful measurements on an antenna range..


Jimmie

After I could not stand the Fiesta any longer I ordered a new Cadillac
Cimarron. I did not want to drill any holes in the new Caddy so I
bought one of the thru the glass end fed whips. Its performance was OK
and it did not draw attention to the vehicle so I lived with it.
130,000 miles later it went to our son radio, antenna and all! It only
made sense when he was licensed. If I were doing it again I would have
drilled the appropriated hole in the roof above the dome light and
installed a Larsen 2m & 400 antenna. That was the last time I
hesitated about drilling a hole where I needed it.

Now that I am in a 2008 Chrysler Minivan I have taken the lazy way out
and placed a mag mount quarter wave on the luggage rack (no scratching
there) with the coax ty-wrapped to the rack so there is not enough
slack to allow real damage if it gets knocked off. An itty-bitty Yaesu
FT-90 sits on a sticky pad on the dash and plugs into one of the
vehicles many12v power outlets. The power outlets are not like the
cigarette lighters of the past. They are well installed and fused at
20 amps. As long as you purchase a plug to handle the power and trim
the cable to what is necessary all is well.

The FT-90 gets too hot to handle and shuts down on lengthy rag chews
at full power, but does fine at lower power settings.

You can waste a lot of time and money over killing a mobile antenna
for repeater operation. If you are out in the wide open spaces, maybe
it is worth it!
John Ferrell W8CCW