Here is a line of sight calculator

http://homepages.nildram.co.uk/~vwlo...va/horizon.htm




"Ted" wrote in message
.net...

"Larry" wrote in message
...
wrote in news:1145452422.231162.267680
@i39g2000cwa.googlegroups.com:

Would I be *much* better off... moving the antenna to the top
of the mast... which would be 30 feet higher than where it is now
situated... based on the aforementioned cruising criteria?



Much better off. Altitude and Power are our friends on VHF, which is
line-
of-sight. You climb to the top of the mast, you can see further. So
can't
your VHF radio....do it.


Bill, when was the last time you actually pushed the transmit button on
your marine vhf and who did you try to talk to?

So,

antenna height feet, horizon miles

Boat Coast Horizon
6 100 17
30 100 22


The range with the coastal stations doesnt change so much and the DSC calls
will be received from much further away. For emergency calls to the coast
the antenna difference is not so much, boat to boat is a different story.

J

"Jester" wrote in :

For emergency calls to the coast
the antenna difference is not so much, boat to boat is a different story.


And you have to factor in the damned marinas and their 70' antenna towers
running 25 watts to talk to the motoryacht 200 ft away coming towards their
docks. FCC should restrict marinas to antennas 20' off the water running
1/2 watt.....or walkie talkies.

Larry wrote:
snip
And you have to factor in the damned marinas and their 70' antenna towers
running 25 watts to talk to the motoryacht 200 ft away coming towards their
docks. FCC should restrict marinas to antennas 20' off the water running
1/2 watt.....or walkie talkies.

?? You're joking right? Did you know that more Watts gives them more
range? And that people can sometimes reasonably expect to communicate
with things that are beyond their visual (not radio) line of sight?

What would really make more sense to me is to make everyone have a radio
that shifts to the low power transmit mode when they transmit after a
received signal had a power level above a certain point. Add a LED so
the people can tell which mode they are transmitting in. And also give
them a power over ride control that will let them cancel the automated
feature when they feel the extra power is appropriate.

Someone is always going to be "too close" and someone else is always
going to "too far away".

And how about this? A radio that will not transmit if the antenna loop
shows an resistance above a certain level. That would get the folks
with bad installs and weathered connectors off the air.

Oh yeah, and add a SWR monitoring circuit too! If the SWR is more than
1.5:1 it won't transmit.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

In article ,
Larry wrote:

FCC should restrict marinas to antennas 20' off the water running
1/2 watt.....or walkie talkies.

Nope, the Marinra Operators just need to be EDUCATED, on how to use
the 1 Watt switch on their radios, when talking to a vessel they can see
out the window........

Me Educated = 2X4 up the side of the opoeraters head.......

Me wrote in news:Me-9B7317.11542425052006
@netnews.worldnet.att.net:

Nope, the Marinra Operators just need to be EDUCATED, on how to use
the 1 Watt switch on their radios, when talking to a vessel they can see
out the window........



One watt from a 9db antenna at 70', used to advertise the marina simply by
it telling boaters their name, is of no use. Marina operators are teenage
kids from the local college working the docks, here. They need WALKIE
TALKIES in the 100 milliwatt range, not 1 watt radios with 70' towers and
high gain antennas.

On Thu, 25 May 2006 18:42:09 -0400, Larry wrote:

Marina operators are teenage
kids from the local college working the docks, here. They need WALKIE
TALKIES in the 100 milliwatt range,

And that is exactly what most dockmasters use.

The marina office on the other hand, needs increased range to
communicate with boats looking for dock space. They need to minimize
their time on channel 16 and most do a good job of that in my
experience.

Wayne.B wrote in
:

boats looking for dock space

Boats looking for dock space need to use the TELEPHONE in their pockets.
Channel 16...or 68 or 69 isn't their private sales channel. Their phone
numbers are located in the various cruise guides. Talk to them as long as
you like.

I caught a boat dealer at an in-the-water boatshow on Channel 72 using
marine walkies for their business. FCC agreed they didn't need to use
marine radio to sell boats, and told them so in the NAL FCC sent them...(c;

I wouldn't have called FCC had the ******* not ****ed at me for asking why
he wasn't using his cellphones or even Family Radio Service walkies at the
show. Talking him off marine radio wasn't possible with such arrogance in
the way. FCC seems to have changed his mind.

Wayne.B wrote:

And that is exactly what most dockmasters use.

The marina office on the other hand, needs increased range to
communicate with boats looking for dock space. They need to minimize
their time on channel 16 and most do a good job of that in my
experience.

I've talked to marinas from southern Florida to Down East Maine and
can't remember calling a Marina on the calling channel and not being
immediately requested to shift to a working channel. That is the way
the system is supposed to work and it works well that way.

If I know the working channel I eliminate the preliminary call on the
calling channel.

The biggest problem on VHF marine bands are new boaters who are not
familiar with procedure, next are arrogant pricks that can't be bothered
to learn how to use it, and a final most irritating factor are the folks
that learned procedure by watching Smokey and the Bandit.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)