Larry,

Would have the URL for Waste Marine, I can't see this listed in Google?
I wonder if you have a typo, it seems an odd name for a company selling
marine equipment :-)

Cheers,

John
"Larry W4CSC" wrote in message
...
"MazingTree" wrote in
.uk:

It's an older style Navico, I only get about a 10 mile range out at
sea, Yacht to yacht, although I can just reach the Coast Guard from
around the Eddystone (about 15 miles to the coast) This woulnd't seem
so bad, except my brand new ICOM M31 portable gives exactly the same
range, both tramistting and receiving, and that's using it down at
deck level, and at only 5W output! whereas my Main boat VHF has an
aerial on the top of the mast.

Ok, let's splurge and drop by Waste Marine for a Shakespeare VHF power/SWR
meter. It's a little white meter with a switch and adjustment control on
the front and two coax connectors, one on each side. $30. You'll need a
short coax jumper to go from the meter's transmitter connector to the VHF
transceiver. If you also buy two right-angle PL-259/SO-239 connectors to
make the coax jacks come out the back of it, instead of the side, you can
make a neat permanent installation of the meter on the panel next to the
radio so you KNOW it's actually transmitting and that the antenna is OK at
any time you don't get an answer.

Use is simple. To check the antenna out, put the meter switch in the SET
position, key the transmitter on some channel in the middle of the band
(NOT CHANNEL 16!) and rotate the little adjustment control until the meter
is at the SET mark at full scale. Now, switch to SWR position and read
the
SWR scale on the meter, while still holding the transmitter keyed. A
perfect antenna, which rarely exists, will show no movement of the needle
off the 1 on the SWR scale, indicating no reflected power back from the
antenna. All the power is going out on the air. Any reading on SWR below
2:1 (the 2 on the SWR scale) is fine. 2:1 means you're losing 10% of your
power back from the antenna. At the antenna it's worse than that but
noone
can really tell the difference out on the horizon between 25W and 15W. If
the SWR is higher than 2:1, especially if it goes way up off the SWR
scale,
which only goes halfway up at 3:1, the antenna or the cable is
TOAST...probably from a lightning hit or broken coaxial cable.

Worst case....SWR sucks over 3:1....what now?......

Now we get out the bosun's chair and have the galley slaves haul us, and
our SWR meter, up the mast to the antenna. Move the jumper coax cable
from
the transmitter jack to the antenna jack as up at the top it will be
jumpering the meter to the antenna. Unplug the coax cable off the
antenna,
after the galley slaves secure the line to a cleat, please, and connect it
to the transmitter jack on our meter. Connect the open end of the jumper
coax to the antenna. Move a galley slave to the radio and have him/her
turn it on. Repeat the SWR set and measurement procedure above. If you
have to significantly move the SET control from the position you had it at
the transceiver end of the coax....or.....if you get little or no reading
at all....the coax is TOAST. Replace it and start measuring again.

Ok, what if we get good power level up the coax? Switch to SWR position
and read the SWR under the antenna, now. It would normally be a little
higher than what you'd measure at the transceiver on a good antenna
because
the reflected power that makes the SWR position run is attenuated by the
cable when we measured it back at the radio. That'd be normal. Again,
the
SWR here should be less than 2:1. If it's high, the antenna is toast! Go
to your favorite marine "discount" dealer and order a Metz Manta 6 VHF
antenna, not that piece of plastic crap with COAX RUNNING OUT OF THE
PLASTIC they'll invariably try to pawn off on your. The Metz is
guaranteed
for life. They'll send you a new one if you ever tear up this one. It's
the best antenna for sailboat masts....damned near indestructable. it
comes with a right-angle stainless bracket to mount it to the mast if your
current one isn't compatible.
http://www.metzcommunication.com/manta6.htm
You won't need the handrail mount. Mounted on the handrail sucks.
ALTITUDE IS OUR FRIEND ON VHF!


Does anyone have any thoughts about what range I can expect yacht to
yacht on a 32 footer sailing boat with mast head antenna with 25
Watts.

Daytime, normal weather....50' mast to 50' mast...probably 15 miles...a
little over the visual horizon from the top of the mast. VHF is line-of-
sight to the radio horizon. Mathematically it's:
http://continuouswave.com/whaler/reference/VHF.html

As you can see from that, the major concern is "path loss" and antenna
height. The 3dB Metz gives you double whatever power is at the end of the
cable atop the mast in Effective Radiated Power (ERP) The 6dB antenna is
too tall to make sense up there...easily destroyed plastic.



I am considering purchasing the ICOM M421, do you think this is the
best bet, or could the aerial be faulty. I have checked all the deck
level connections and these seem OK.

Before we spend hundreds on a new radio, let's get the antenna checked out
with the cheap meter, first. If the SWR is reasonable, under 2:1, when
you
test it at the radio, THEN we'll flip the switch to POWER mode and read
the
handy little wattmeter, which is "fairly accurate" at LOW SWR READINGS,
being most accurate at 1:1 with no reflected power. Check the 25W high
power and 1 watt low power in this meter mode. As the SWR increases, this
reading increases, so don't get way excited if it reads 30 watts at 2:1
SWR. It was calibrated into a perfect dummy load at the factory.

Now, of course, if you're reading ZERO and can't get the meter to SET in
SWR mode....then we've got a bad transmitter. Your choice to repair or
replace. If it's old, dump it.
They stopped making my beloved M-59 the jetboat jumping waves couldn't
destroy...dammit. Lionheart has an M-602 on the mainmast Metz and an M-59
on the mizzen lower down. Captain Geoffrey likes the way the M-602
matches
the M-802 HF panel...(c; There's no difference in the range of the big
expensive 602 and the old M-59 I can tell. M-59 has new clothes. They
call it the M-302, now. If you don't need the extra toys of the M-402,
like remote Commander mic, etc., it has the same radio operation.

Any Icom is fine. M-127s, the Radio Of The Year back in 2000 and before,
is a great radio. They're still available, but discontinued, now. Gotta
keep cranking up those model numbers, you know!

As the range webpage shows, 10 miles is pretty fair, boat 2 boat on VHF.
The investment in the little SWR/Power meter will help you find out the
true health of the radio/antenna/cable combo....Everyone should buy one.