I am about to raise the new mizzen mast on my old Van de Stadt ketch
and I have been thinking about some other possible uses for the mast
head. Would it make sense to place a wi-fi antenna up there to make
better use of the hot spots that may be available in some communities?
Any suggestions for other hardware on the mizzen would be appreciated.
I am already putting a spare anchor light and VHF antenna, but I know
I will think of something else, when it is too late.
Tom

On Tue, 1 Apr 2008 18:16:23 -0700 (PDT), "
wrote:

I am about to raise the new mizzen mast on my old Van de Stadt ketch
and I have been thinking about some other possible uses for the mast
head. Would it make sense to place a wi-fi antenna up there to make
better use of the hot spots that may be available in some communities?

It makes a lot of sense if you do it right. The potential problem is
the long run of cable up the mast which will create a lot of signal
loss even with the very best LMR400 cable. The soulution is to use a
weatherproof wifi bridge at the masthead which supports Power Over
Ethernet (POE) technology. POE allows you to run ethernet cable up
the mast instead of coax cable. Two units that I have been successful
with on my boat are the Senao 3220-EXT and also the Senao/Engenius
EOC-3610S-EXT.

http://tinyurl.com/2efrmf

and

http://tinyurl.com/28qx4n

You will also need a high gain, omni-directional antenna and a "Type N
to RP-SMA" cable adapter:

http://tinyurl.com/38mwak

and

http://tinyurl.com/2j6p29

Of the two bridges, I prefer the EOC-3610S-EXT because of its somewhat
greater power and receive sensitivity. The 3220 is slightly easier to
configure however. You will need a source of 110 volt power for the
POE adapter, best bet is a small sine wave inverter which can also
power your laptop.

"Wayne.B" wrote in message
...


The potential problem is
the long run of cable up the mast which will create a lot of signal
loss even with the very best LMR400 cable.

That cable has a loss of about 6 dB/100 ft at WiFi frequencies. A colinear
antenna can have gain way in excess of the loss and maintain an isotropic
pattern in the horizontal plane. Figure 50' of cable with 3 dB of loss added
to a 9 dB gain antenna is a net gain of 6 dB. It could work out quite well.
One has to consider the entire system, not just isolated elements. This is a
much cheaper and more reliable solution than an active bridge up on the mast
head.

Glory!

Antenna:

http://www.nodomainname.co.uk/Omnico...4collinear.htm

On Wed, 2 Apr 2008 09:32:14 -0600, "Bob Crantz"
wrote:

This is a
much cheaper and more reliable solution than an active bridge up on the mast
head.

Believe it or not my bridges have been very reliable. I know others
who are using similar configurations without any issues. Of course in
the event of a nearby lightning strike, all bets are off regardless of
bridge location. I already have a 9 db antenna and would not want an
extra 3 db of loss in my system if I could avoid it. It can make all
the difference on a distant access point.

"Bob Crantz" wrote in message
...

"Wayne.B" wrote in message
...


The potential problem is
the long run of cable up the mast which will create a lot of signal
loss even with the very best LMR400 cable.

That cable has a loss of about 6 dB/100 ft at WiFi frequencies. A colinear
antenna can have gain way in excess of the loss and maintain an isotropic
pattern in the horizontal plane. Figure 50' of cable with 3 dB of loss
added to a 9 dB gain antenna is a net gain of 6 dB. It could work out
quite well. One has to consider the entire system, not just isolated
elements. This is a much cheaper and more reliable solution than an active
bridge up on the mast head.

Glory!


I have personal experience with respect to this topic. Putting a wi-fi
antenna at the masthead is the WRONG thing to do. You don't want it high up.
You want it low down. It gets better reception low. The signals seem to be
stronger low. Mount a good amplified antenna at deck level for the best
reception. No need to worry about long lengths of co-ax at all.

Here's a good antenna that works well and is priced reasonably.
http://www.radiolabs.com/products/wi...ne-antenna.php

Wilbur Hubbard

"Wilbur Hubbard" wrote in message
anews.com...
I have personal experience with respect to this topic. Putting a wi-fi
antenna at the masthead is the WRONG thing to do. You don't want it high
up. You want it low down. It gets better reception low. The signals seem
to be stronger low. Mount a good amplified antenna at deck level for the
best reception. No need to worry about long lengths of co-ax at all.

Here's a good antenna that works well and is priced reasonably.
http://www.radiolabs.com/products/wi...ne-antenna.php

Wilbur Hubbard


If your antenna is vertically polarized you could see a 3 dB increase in
signal if it placed over a conducting ground plane such as salt water. This
is explained by the theory of images, which in effect doubles the antenna
gain toward the horizon. If the antenna is horizontally polarized the
radiation pattern become directed more skyward and there is an associated
decrease in gain toward the horizon. Wilbur, you have a keen sense of
observation.

"Bob Crantz" wrote in message
...

"Wilbur Hubbard" wrote in message
anews.com...
I have personal experience with respect to this topic. Putting a wi-fi
antenna at the masthead is the WRONG thing to do. You don't want it high
up. You want it low down. It gets better reception low. The signals seem
to be stronger low. Mount a good amplified antenna at deck level for the
best reception. No need to worry about long lengths of co-ax at all.

Here's a good antenna that works well and is priced reasonably.
http://www.radiolabs.com/products/wi...ne-antenna.php

Wilbur Hubbard


If your antenna is vertically polarized you could see a 3 dB increase in
signal if it placed over a conducting ground plane such as salt water.
This is explained by the theory of images, which in effect doubles the
antenna gain toward the horizon. If the antenna is horizontally polarized
the radiation pattern become directed more skyward and there is an
associated decrease in gain toward the horizon. Wilbur, you have a keen
sense of observation.


Thanks. I can't help but be brilliant.

From the spec sheet: http://www.radiolabs.com/downloads/WaveRV.pdf

vertical beamwidth - 35 degrees
horizontal beamwidth - 360 degrees.

Wilbur Hubbard

On Wed, 2 Apr 2008 13:10:05 -0600, "Bob Crantz"
wrote:


"Wilbur Hubbard" wrote in message
tanews.com...
I have personal experience with respect to this topic. Putting a wi-fi
antenna at the masthead is the WRONG thing to do. You don't want it high
up. You want it low down. It gets better reception low. The signals seem
to be stronger low. Mount a good amplified antenna at deck level for the
best reception. No need to worry about long lengths of co-ax at all.

Here's a good antenna that works well and is priced reasonably.
http://www.radiolabs.com/products/wi...ne-antenna.php

Wilbur Hubbard


If your antenna is vertically polarized you could see a 3 dB increase in
signal if it placed over a conducting ground plane such as salt water.

6dB. Principle of superposition. No power splitting required for the
image. No change in antenna radiation impedance if the distance from
antenna to ground plane is large in terms of wavelengths,
as is likely to be the case in this situation.

I think it would be wise to learn something about 2.4ghz wave propagation
and the Fresnel effect before you make that statement. If you just want a
couple of hundred yards range deck mounting is fine but for 2 miles plus you
need to be UP.

By far the best solution is a waterproof wifi bridge at the masthead
connected by Ethernet with POE to a hub. Long range because there is
minimal coax loss and a wide Fresnel zone.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Wilbur Hubbard" wrote in message
anews.com...

"Bob Crantz" wrote in message
...

"Wayne.B" wrote in message
...


The potential problem is
the long run of cable up the mast which will create a lot of signal
loss even with the very best LMR400 cable.

That cable has a loss of about 6 dB/100 ft at WiFi frequencies. A
colinear antenna can have gain way in excess of the loss and maintain an
isotropic pattern in the horizontal plane. Figure 50' of cable with 3 dB
of loss added to a 9 dB gain antenna is a net gain of 6 dB. It could work
out quite well. One has to consider the entire system, not just isolated
elements. This is a much cheaper and more reliable solution than an
active bridge up on the mast head.

Glory!


I have personal experience with respect to this topic. Putting a wi-fi
antenna at the masthead is the WRONG thing to do. You don't want it high
up. You want it low down. It gets better reception low. The signals seem
to be stronger low. Mount a good amplified antenna at deck level for the
best reception. No need to worry about long lengths of co-ax at all.

Here's a good antenna that works well and is priced reasonably.
http://www.radiolabs.com/products/wi...ne-antenna.php

Wilbur Hubbard