I am going to add a fix-mounted VHF radio in my boat. I would like to
know whether I should get a 3dB 3-ft antenna or a 6dB 8-ft antenna to
mount on the T-top. My questions a

- Books and people in this newsgroup recommend 6dB 8-ft antenna for a
small powered boat. This sounds good. But I am wondering whether a
8-ft antenna is too large for my 18-ft boat. Will this make the boat
"look" very top-heavy? Do people really use a 8-ft antenna in a small
boat like mine?

- The other alternative is a 3dB 3-ft antenna and accepting the
reduced range. Does a 3dB antenna provide a good enough range given
the fact that I won't go too far away from the shore (because the boat
is considered as a "bay boat")?

- According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

Thanks for any info in advance.

Jay Chan

wrote in message
ups.com...
I am going to add a fix-mounted VHF radio in my boat. I would like to
know whether I should get a 3dB 3-ft antenna or a 6dB 8-ft antenna to
mount on the T-top. My questions a

- Books and people in this newsgroup recommend 6dB 8-ft antenna for a
small powered boat. This sounds good. But I am wondering whether a
8-ft antenna is too large for my 18-ft boat.


Nope.


Will this make the boat
"look" very top-heavy?


Nope.


Do people really use a 8-ft antenna in a small
boat like mine?

Yep.



- The other alternative is a 3dB 3-ft antenna and accepting the
reduced range. Does a 3dB antenna provide a good enough range given
the fact that I won't go too far away from the shore (because the boat
is considered as a "bay boat")?


Purchase the 8 footer to get the greatest range.



- According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

Thanks for any info in advance.

Jay Chan

JimH wrote:
wrote in message
ups.com...
I am going to add a fix-mounted VHF radio in my boat. I would like to
know whether I should get a 3dB 3-ft antenna or a 6dB 8-ft antenna to
mount on the T-top. My questions a

- Books and people in this newsgroup recommend 6dB 8-ft antenna for a
small powered boat. This sounds good. But I am wondering whether a
8-ft antenna is too large for my 18-ft boat.


Nope.


Will this make the boat
"look" very top-heavy?


Nope.


Do people really use a 8-ft antenna in a small
boat like mine?

Yep.



- The other alternative is a 3dB 3-ft antenna and accepting the
reduced range. Does a 3dB antenna provide a good enough range given
the fact that I won't go too far away from the shore (because the boat
is considered as a "bay boat")?


Purchase the 8 footer to get the greatest range.


- According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

Thanks for any info in advance.

Jay Chan

Thanks for the useful info. I will go ahead to order a 6dB 8-ft
antenna and a fix-mounted VHF radio.

Jay Chan

On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.

"Wayne.B" wrote in message
...
On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.


I'm with Wayne on this one.

The dB rating plays a relatively minor role in the distance the signal
travels. The height of the transmitting antenna plays a larger role. But
the height of the receiving antenna is the most important element.

Example:
A 3' antenna mounted on the top of the gunwale of a small boat might be 5'
above the water line. It can travel only 5 miles to another antenna that
is only 5' off the water...but can travel 15 miles to an antenna that is
100' high (like at a Coast Guard station).

An 8' antenna mounted on the same gunnel can travel 9 miles to another
antenna that is only 5' off the water (big difference!), but only travels 18
miles to that 100' antenna (a not so big difference from the 3' antenna).

If the CG antenna is 250' above sea level (mounted on a tower on a mountain
for example), the 3' antenna can travel 23 miles...and the 8' travels 25
miles.

So the question is...
Who do you want to call with that radio?

Another boat within 5 miles? Then either antenna is fine.

The Coast Guard when you're 10-15 miles from shore? Then either antenna is
fine once again.






Here's a good link to explain this further:
http://www.yachtworks.net/Store/antennas.htm

"Shortwave Sportfishing" wrote in message
...
On Fri, 13 Jan 2006 23:35:25 GMT, "NOYB" wrote:


"Wayne.B" wrote in message
. ..
On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.


I'm with Wayne on this one.

The dB rating plays a relatively minor role in the distance the signal
travels. The height of the transmitting antenna plays a larger role. But
the height of the receiving antenna is the most important element.

Example:
A 3' antenna mounted on the top of the gunwale of a small boat might be 5'
above the water line. It can travel only 5 miles to another antenna that
is only 5' off the water...but can travel 15 miles to an antenna that is
100' high (like at a Coast Guard station).

An 8' antenna mounted on the same gunnel can travel 9 miles to another
antenna that is only 5' off the water (big difference!), but only travels
18
miles to that 100' antenna (a not so big difference from the 3' antenna).

If the CG antenna is 250' above sea level (mounted on a tower on a
mountain
for example), the 3' antenna can travel 23 miles...and the 8' travels 25
miles.

So the question is...
Who do you want to call with that radio?

Another boat within 5 miles? Then either antenna is fine.

The Coast Guard when you're 10-15 miles from shore? Then either antenna
is
fine once again.

Here's a good link to explain this further:
http://www.yachtworks.net/Store/antennas.htm

finally - a civilian who gets it.

That's the engineer in me. I like to read how things work before making my
purchases.

"NOYB" wrote in message
ink.net...

"Shortwave Sportfishing" wrote in message
...
On Fri, 13 Jan 2006 23:35:25 GMT, "NOYB" wrote:


"Wayne.B" wrote in message
...
On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.


I'm with Wayne on this one.

The dB rating plays a relatively minor role in the distance the signal
travels. The height of the transmitting antenna plays a larger role. But
the height of the receiving antenna is the most important element.

Example:
A 3' antenna mounted on the top of the gunwale of a small boat might be
5'
above the water line. It can travel only 5 miles to another antenna
that
is only 5' off the water...but can travel 15 miles to an antenna that is
100' high (like at a Coast Guard station).

An 8' antenna mounted on the same gunnel can travel 9 miles to another
antenna that is only 5' off the water (big difference!), but only travels
18
miles to that 100' antenna (a not so big difference from the 3' antenna).

If the CG antenna is 250' above sea level (mounted on a tower on a
mountain
for example), the 3' antenna can travel 23 miles...and the 8' travels 25
miles.

So the question is...
Who do you want to call with that radio?

Another boat within 5 miles? Then either antenna is fine.

The Coast Guard when you're 10-15 miles from shore? Then either antenna
is
fine once again.

Here's a good link to explain this further:
http://www.yachtworks.net/Store/antennas.htm

finally - a civilian who gets it.

That's the engineer in me. I like to read how things work before making
my purchases.




Looking at specs is fine. But what happens when the boat, intended for only
near shore use, loses power when at the fringe range of the 3 foot antenna
and there are no boaters anywhere close?

I see no downside with going with the 8 foot antenna.

" JimH" jimh_osudad@yahooDOT comREMOVETHIS wrote in message
...

"NOYB" wrote in message
ink.net...

"Shortwave Sportfishing" wrote in message
...
On Fri, 13 Jan 2006 23:35:25 GMT, "NOYB" wrote:


"Wayne.B" wrote in message
m...
On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.


I'm with Wayne on this one.

The dB rating plays a relatively minor role in the distance the signal
travels. The height of the transmitting antenna plays a larger role.
But
the height of the receiving antenna is the most important element.

Example:
A 3' antenna mounted on the top of the gunwale of a small boat might be
5'
above the water line. It can travel only 5 miles to another antenna
that
is only 5' off the water...but can travel 15 miles to an antenna that is
100' high (like at a Coast Guard station).

An 8' antenna mounted on the same gunnel can travel 9 miles to another
antenna that is only 5' off the water (big difference!), but only
travels 18
miles to that 100' antenna (a not so big difference from the 3'
antenna).

If the CG antenna is 250' above sea level (mounted on a tower on a
mountain
for example), the 3' antenna can travel 23 miles...and the 8' travels 25
miles.

So the question is...
Who do you want to call with that radio?

Another boat within 5 miles? Then either antenna is fine.

The Coast Guard when you're 10-15 miles from shore? Then either antenna
is
fine once again.

Here's a good link to explain this further:
http://www.yachtworks.net/Store/antennas.htm

finally - a civilian who gets it.

That's the engineer in me. I like to read how things work before making
my purchases.




Looking at specs is fine. But what happens when the boat, intended for
only near shore use, loses power when at the fringe range of the 3 foot
antenna and there are no boaters anywhere close?

The point I was making is that the 3' antenna will reach a CG tower more
than 15 miles away...and the 8' antenna will reach only about 3 miles
further. That's not really an appreciable difference unless his fishing
grounds are consistently in the 16-18 mile range.

Besides, if he's out in an 18' boat more than 15 miles from shore, he better
be carrying an EPIRB...and filing a float plan. Should he fail to return as
planned, a CG aircraft will pick his radio up from nearly 30 miles or
more...no matter how big his antenna is.

Keep in mind that the antenna on passing ships/shrimp boats/etc. are at
least 30-50' above the water...meaning that his 3' antenna will reach them
almost as well as the 8' antenna.

As I said before, the height of the receiving antenna on most vessels that
are going to render assistance has a greater influence on your radio's
effective range than the height of your own antenna.

I regularly hear CG broadcasts coming out of St. Pete...and I'm 160 miles
from them. Granted, they're using higher power equipment and very tall
broadcast towers (perhaps broadcasting from aircraft), but I hear them on my
boat with the 3' antenna just as well as the Grady with an 8' antenna on top
of the hardtop.

"NOYB" wrote in message
ink.net...

" JimH" jimh_osudad@yahooDOT comREMOVETHIS wrote in message
...

"NOYB" wrote in message
ink.net...

"Shortwave Sportfishing" wrote in message
...
On Fri, 13 Jan 2006 23:35:25 GMT, "NOYB" wrote:


"Wayne.B" wrote in message
om...
On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't have
it. My boat is a fiberglass boat. What's the alternative? Does
this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.


I'm with Wayne on this one.

The dB rating plays a relatively minor role in the distance the signal
travels. The height of the transmitting antenna plays a larger role.
But
the height of the receiving antenna is the most important element.

Example:
A 3' antenna mounted on the top of the gunwale of a small boat might be
5'
above the water line. It can travel only 5 miles to another antenna
that
is only 5' off the water...but can travel 15 miles to an antenna that
is
100' high (like at a Coast Guard station).

An 8' antenna mounted on the same gunnel can travel 9 miles to another
antenna that is only 5' off the water (big difference!), but only
travels 18
miles to that 100' antenna (a not so big difference from the 3'
antenna).

If the CG antenna is 250' above sea level (mounted on a tower on a
mountain
for example), the 3' antenna can travel 23 miles...and the 8' travels
25
miles.

So the question is...
Who do you want to call with that radio?

Another boat within 5 miles? Then either antenna is fine.

The Coast Guard when you're 10-15 miles from shore? Then either
antenna is
fine once again.

Here's a good link to explain this further:
http://www.yachtworks.net/Store/antennas.htm

finally - a civilian who gets it.

That's the engineer in me. I like to read how things work before making
my purchases.




Looking at specs is fine. But what happens when the boat, intended for
only near shore use, loses power when at the fringe range of the 3 foot
antenna and there are no boaters anywhere close?

The point I was making is that the 3' antenna will reach a CG tower more
than 15 miles away...and the 8' antenna will reach only about 3 miles
further. That's not really an appreciable difference unless his fishing
grounds are consistently in the 16-18 mile range.

Besides, if he's out in an 18' boat more than 15 miles from shore, he
better be carrying an EPIRB...and filing a float plan. Should he fail to
return as planned, a CG aircraft will pick his radio up from nearly 30
miles or more...no matter how big his antenna is.

Keep in mind that the antenna on passing ships/shrimp boats/etc. are at
least 30-50' above the water...meaning that his 3' antenna will reach them
almost as well as the 8' antenna.

As I said before, the height of the receiving antenna on most vessels that
are going to render assistance has a greater influence on your radio's
effective range than the height of your own antenna.

I regularly hear CG broadcasts coming out of St. Pete...and I'm 160 miles
from them. Granted, they're using higher power equipment and very tall
broadcast towers (perhaps broadcasting from aircraft), but I hear them on
my boat with the 3' antenna just as well as the Grady with an 8' antenna
on top of the hardtop.


NOYB, I hear what you are saying, but..........being able to broadcast an
additional 3 miles while drifting further out to sea with a dead engine in
the ocean can be a life saver.

I often do a simple cost/benefit analysis when trying to make a decision
like this, and in Jay's case it is a no brainer.

" JimH" jimh_osudad@yahooDOT comREMOVETHIS wrote in message
...

"NOYB" wrote in message
ink.net...

" JimH" jimh_osudad@yahooDOT comREMOVETHIS wrote in message
...

"NOYB" wrote in message
ink.net...

"Shortwave Sportfishing" wrote in message
...
On Fri, 13 Jan 2006 23:35:25 GMT, "NOYB" wrote:


"Wayne.B" wrote in message
news:184gs1psncof0p2otitab109lbsdrmpimi@4ax. com...
On 13 Jan 2006 09:56:30 -0800, "
wrote:

According to post in this newsgroup, we need a metal plate for
grounding if we use a 3dB antenna, and a fiberglass boat doesn't
have
it. My boat is a fiberglass boat. What's the alternative? Does
this
mean that I cannot use 3dB antenna?

There is no need for a ground with a VHF antenna.

Either the 3 db or 6 db antenna will be adequate for near shore
coastal operation.


I'm with Wayne on this one.

The dB rating plays a relatively minor role in the distance the signal
travels. The height of the transmitting antenna plays a larger role.
But
the height of the receiving antenna is the most important element.

Example:
A 3' antenna mounted on the top of the gunwale of a small boat might
be 5'
above the water line. It can travel only 5 miles to another antenna
that
is only 5' off the water...but can travel 15 miles to an antenna that
is
100' high (like at a Coast Guard station).

An 8' antenna mounted on the same gunnel can travel 9 miles to another
antenna that is only 5' off the water (big difference!), but only
travels 18
miles to that 100' antenna (a not so big difference from the 3'
antenna).

If the CG antenna is 250' above sea level (mounted on a tower on a
mountain
for example), the 3' antenna can travel 23 miles...and the 8' travels
25
miles.

So the question is...
Who do you want to call with that radio?

Another boat within 5 miles? Then either antenna is fine.

The Coast Guard when you're 10-15 miles from shore? Then either
antenna is
fine once again.

Here's a good link to explain this further:
http://www.yachtworks.net/Store/antennas.htm

finally - a civilian who gets it.

That's the engineer in me. I like to read how things work before
making my purchases.




Looking at specs is fine. But what happens when the boat, intended for
only near shore use, loses power when at the fringe range of the 3 foot
antenna and there are no boaters anywhere close?

The point I was making is that the 3' antenna will reach a CG tower more
than 15 miles away...and the 8' antenna will reach only about 3 miles
further. That's not really an appreciable difference unless his fishing
grounds are consistently in the 16-18 mile range.

Besides, if he's out in an 18' boat more than 15 miles from shore, he
better be carrying an EPIRB...and filing a float plan. Should he fail to
return as planned, a CG aircraft will pick his radio up from nearly 30
miles or more...no matter how big his antenna is.

Keep in mind that the antenna on passing ships/shrimp boats/etc. are at
least 30-50' above the water...meaning that his 3' antenna will reach
them almost as well as the 8' antenna.

As I said before, the height of the receiving antenna on most vessels
that are going to render assistance has a greater influence on your
radio's effective range than the height of your own antenna.

I regularly hear CG broadcasts coming out of St. Pete...and I'm 160 miles
from them. Granted, they're using higher power equipment and very tall
broadcast towers (perhaps broadcasting from aircraft), but I hear them on
my boat with the 3' antenna just as well as the Grady with an 8' antenna
on top of the hardtop.


NOYB, I hear what you are saying, but..........being able to broadcast an
additional 3 miles while drifting further out to sea with a dead engine in
the ocean can be a life saver.

I often do a simple cost/benefit analysis when trying to make a decision
like this, and in Jay's case it is a no brainer.

When I bought my 17' Whaler, it had an 8' antenna mounted on top the
gunwale. My brother has a 3' on the railing of the center console of his
18' Whaler.

It's not about the cost. I'd go with the 3' on top of the railing of the
center console, because it's out of the way when fighting a fish...and the
height above the water line is only a couple of feet less than my 8'.