In article ,
Jon Gauthier wrote:

I haven't fired up EZNEC yet, but I was wondering how a standard 3dBi
marine whip would perform on the 2m ham bands. Since the marine
frequencies are 156.050-157.425 MHz, what could I expect at 144-148 MHz?

If it won't cut it, then does anyone have any recommendations for a
dual-band antenna (commercial or home-built)?

Jon

last boat i used a nice Diamond 2m/440 mobile antenna for my
Yeasu dualbander. the trick was the mount.

i bought a mounting kit containing (among other things)
a waterproof roof-mount UHF male that would
mate with the UHF female of the antenna base.
(an extra set of assorted O-rings came in handy, too.)

i then made an adapter to go between a standard marine
1"-14 mount from some bronze pipe fittings and a short piece
of 1.5 or 2" brass pipe acquired at West Marine.

the top was a pipe cap
which i drilled to take the UHF roof-mount which then transitioned
down to to the 1-14 with a reducer. the coax fed down through
the exit hole in the mount to the drip loop and back up
through the clamshell into the arch side where it was mounted.

after putting the adapter together i prepped and painted it with
several coats of white epoxy paint.

if i had a lathe, i would have turned down the fittings to
be both smoother and less obtrusive, and boring the cap
would have been easier than drilling it, not to mention
turning a flat on the top. but all told, the piece came
out fine - it worked great and nobody went blind looking at it.

there is a business opportunity, though, for someone to
make a line of mounts to put quality ham antennas on
1-14 marine mounts.

cheers,
-mo
N4NLN

ps - the same thing could certainly be fabricated from PVC,
probably with less effort, but i figured that the metal
would last longer. whether i'd live long enough to observe
the difference is an interesting question.