Bob Bob wrote:
Hi Larry

Cant help you with a specific choice. Be aware though that considering
the boat thumps around in the water the antenna will never be always
quite vertical. If you run a "gain" device you may find you'll get a
more choppy signal and max radiation lobe that never quite line up with
the optimum. As an indicator a 5/8 (car mobile) whip in rolling country
can actually work worse than a 1/4 wave. (And also in a city/skyscraper
area, but for a different reason)

FWIW I do remember a 5/8 over 1/4 wave design some years ago where you
could remove the phasing section and above. A handy feature.

Of course if the boat motor is broken and there is no swell it may be
good to have gain!

Cheers Bob VK2YQA

Larry wrote:

I've thought about doing just that. A 1/4 wave on 2m is about 19" and
would not require folding down. I was kinda hoping to find some gain
which would also match the VHF Marine band antenna next to where it
would be, but I can't find anything so far.


Actually, I remembered in the shower this morning that a 1/4 wave must
have a ground plane to work against and the hardtop on which it would be
installed is all fiberglass - no metal. Whoops! I guess I have to have
some kind of antenna which does not require a ground plane - maybe a 1/2
wave or something similar. Now we're talking enough height that it has
to fold down.

I'll follow the link that Bob gave and see what the guy is using. I
suppose I could disconnect the marine VHF antenna and hook it up to the
ICOM and a SWR meter and see what I get. I guess I should give that a
try. I don't need to do anything to try that.

I know that I'd lose some of whatever gain those things claim, as the
antenna would seldom be completely vertical, but I've never found that
to be all that significant anyway. I just need to have an antenna which
does not rely on a ground plane. Since I'm only fishing on lakes, I
don't think that is all that significant anyway. I've found that marine
VHF gets almost nowhere (nobody around) so I think I'd do better with 2
meters.
--

Larry W1HJF
rapp at lmr dot com