Larry wrote:
Does anyone know of a commercial 2 meter antenna made for boats? Fresh
water exclusively, but this would be mounted on a T-top of a center
console which is towed, so it would have to be able to be tilted down
just like the VHF marine antenna. Thanks.
I just use 1/4 wave whips on mine - one for 2 meters and a longer one
for FM broadcast, mounted on the T-top's antenna mounting plates. Just
something to consider if you cannot find the longer marine antenna that
you're looking for.

73,
bob

Bob Baldwin wrote:

I just use 1/4 wave whips on mine - one for 2 meters and a longer one
for FM broadcast, mounted on the T-top's antenna mounting plates. Just
something to consider if you cannot find the longer marine antenna that
you're looking for.

73,
bob

Thanks, Bob,

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.

--

Larry W1HJF
rapp at lmr dot com

Larry wrote:
Bob Baldwin wrote:

I just use 1/4 wave whips on mine - one for 2 meters and a longer one
for FM broadcast, mounted on the T-top's antenna mounting plates. Just
something to consider if you cannot find the longer marine antenna
that you're looking for.

73,
bob

Thanks, Bob,

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.

Larry,
Those marine antennas are really pretty, and I figured you wanted one
to compliment the existing one. I found at least one guy that uses his
VHF marine antenna on 2 meters, and says the match is better on 2 than
marine. Check
"http://cruisenews.net/cgi-bin/mmham/webbbs_config.pl/noframes/read/1372"
and maybe you can contact him for more info.
73,
bob wa5jot
Power Cat CC / Tops-N-Towers T-Top

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.

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

Hi Larry

Just a quick thought.

Since a moved from the marine band to 2m is down in freq you may get
away with something you can slip over the marine whip to increase C to
ground. I am thinking something loose here, not so much a metal to metal
connection. Since there will be a greater effect at the top end maybe a
piece of metal pipe just sitting close to the top, maybe buffered with a
grommet or something to hold it in place.

Might be worth an experimenting if the 2m VSWR on the marine whip is
beyond bounds!

Of course if you have the money to throw at it, mounting a high gain
vertical on a steadicam mount might solve the movement induced pattern
problems! grin

Cheers Bob VK2YQA

Larry wrote:

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.

Bob Bob wrote:
Hi Larry

Just a quick thought.

Since a moved from the marine band to 2m is down in freq you may get
away with something you can slip over the marine whip to increase C to
ground. I am thinking something loose here, not so much a metal to metal
connection. Since there will be a greater effect at the top end maybe a
piece of metal pipe just sitting close to the top, maybe buffered with a
grommet or something to hold it in place.

Might be worth an experimenting if the 2m VSWR on the marine whip is
beyond bounds!

Of course if you have the money to throw at it, mounting a high gain
vertical on a steadicam mount might solve the movement induced pattern
problems! grin

Cheers Bob VK2YQA

Hi Bob,

Well, after a bit of experimenting (and remember I'm almost always on an
inland lake) I decided to go with the Morad antenna. I've ordered one
and a mount - it will probably be here next week. I'm not too concerned
with pitch and yaw - it will be close enough to vertical!

Yes, I could detune a marine band antenna - for that matter, the SWR is
probably close enough, but this should work and there's some genuine
gain, but not so much I have to worry about keeping it vertical.

Actually, I'm lazy!

73,
--

Larry W1HJF
rapp at lmr dot com