marine wifi??

[captfolly]

I have been disappointed using my laptop internal card for wifi access in marinas and at anchor...is there a ubiquiti product that could I could hoist up the mast and use poe and run it direct to my laptop or to an ap down below in the boat...is configuration fairly simple??...thanks for any input...

George
catamaran "Grace"
charleston, sc

[WHT]

Using directional antennas on a shall boat is problematic as the antennas vertical beamwidth shoots way under and way over the horizon as the boat rocks. This is further made worse when the higher up on the mast you place the antenna. This also holds true for high gain omni antennas.

For this reason, mobile data antennas are usually simple unity gain. The higher the gain of the antenna, the more narrow the vertical beamwidth.

Go with the Bullet and an external omni unity or low gain antenna. Better yet, the Wfi Plus discussed here http://forum.ubnt.com/forum/viewtopic.php?t=7022&highlight= Edited: This is a link to the old forum and not working. Use http://www.ubnt.com/forum/showthread.php?t=14959

Now you could run the network cable down to the PoE side of the power injector and connect the LAN side to a Linksys WRT54G wireless router on a different channel for wireless access on your boat.

[IslandTime]

Using directional antennas on a shall boat is problematic as the antennas vertical beamwidth shoots way under and way over the horizon as the boat rocks. This is further made worse when the higher up on the mast you place the antenna. This also holds true for high gain omni antennas.

The deviation of the beamwidth center line from horizontal will not increase with height.

For this reason, mobile data antennas are usually simple unity gain. The higher the gain of the antenna, the more narrow the vertical beamwidth.

I like to use an 8dbi omni. With the normal 15 degree vertical beam width you get the benefits of the extra gain on receive and have enough beam width to allow for some roll. Since "captfolly" has a cat he won't have to worry about rolling.

Go with the Bullet and an external omni unity or low gain antenna. Better yet, the Wfi Plus discussed here http://forum.ubnt.com/forum/viewtopic.php?t=7022&highlight=

The Bullet appears to be a good solution for boaters if the cable gland will remain watertight even with spray from the underside. I would prefer to see the HP version on a boat to take advantage of the higher power. A cruiser doesn't have any control over the AP so he may need a little extra power so that the WRT54G or similar router in the captains lounge at the marina can hear him. I use the LS2 and if they ever come out with the MiniStation I'll switch to that unless the cost of the Bullet2HP is too good to pass up.

Now you could run the network cable down to the PoE side of the power injector and connect the LAN side to a Linksys WRT54G wireless router on a different channel for wireless access on your boat.

I would set the CPE as a NAT router and feed the cable into the WAN port of the wireless router. Set the CPE and router to different IP segments. You'll end up with a lot fewer IP problems as you move from AP to AP.

Bob Stewart
IslandTime PC (www.islandtimepc.com)

[WHT]

Using directional antennas on a shall boat is problematic as the antennas vertical beamwidth shoots way under and way over the horizon as the boat rocks. This is further made worse when the higher up on the mast you place the antenna. This also holds true for high gain omni antennas.
The deviation of the beamwidth center line from horizontal will not increase with height.
You are correct

I got ahead of myself was thinking back to a discussion in a NG about the period of realignment of a dynamic compensated antenna mount on a sailboat mast which would not apply to what I said before. Sorry about that...

[captfolly]

thanks for the replies WHT and Bob...looks like there are no bullet 2's to be had anywhere at present....I'll continue to read the forum to learn more about all this and try a bullet 2 when they become available...

George

[WHT]

That was my mistake...for some reason I had a flash back to when we were testing ways to keep an omni antenna vertical on a sailboat. Short of several tens of thousand dollars for a gyroscopic controlled mount the ENG antenna use on helicopters.

We made a test jig from a twenty foot long PVC pipe and had two six ione eye bolts as "yardarms" sticking out to the side. We susppend a foot long piece of one inch PVC and swung the pole back and forth to simulate wave action.

The highest antenna had a lot more violent sway, almost going 45º from the vertical and the lowest antenna only about 10º.

[jeroenimo]

May I show you my setup ?

Actually I have a Ns2 but it gives you an idea on how a "marine" setup works flawless on my ship:

this is my NanoStation on my ship with connected cat5e cable in the rigging:
http://dl.getdropbox.com/u/26528/photo-3.jpg
this is my wrt54g with 3rd party firmware inside my ship which runs at 20mW to provide wireless internet inside, you see the PoE injector there too.
(soory for the blurry pic)
http://dl.getdropbox.com/u/26528/photo-2.jpg

The best part is, both the NanoStation and wrt54g run on 12V straight from the ships battery, so no conversion necessary..

Hope this gives you an idea...

Jeroenimo

[captfolly]

thank you jeroenimo....what you have is pretty much what I want to do...I am hoping that a bullet2 with a homebrew omni antenna and connected via ethernet to a netgear wg102 will work. Figuring out all the networking settings for the units is where I am pretty weak and still learning...

fair winds,

George

[jeroenimo]

Figuring out all the networking settings for the units is where I am pretty weak and still learning...

fair winds,

George
That one is quite easy, the way I did it was like this:

The Ns2 is doing the routing for my ships LAN, so I set it to station router mode and let it log in to the wireless network you intend to use , made sure its being a dhcp server on a non usual subnet e.g. 10.11.12.1 set your dhcp server this way it sends leases from 10.11.12.10 till 10.11.12.20 with netmask 255.255.255.0,

Now on my wrt54g I made sure its not acting as a dhcp server and manually set the ip to 10.11.12.2 I set it up as an AP and made the connection secure with wpa2, then I connected the wrt54g(on one of its LAN ports not the "internet" port) with the Ns2 with my cat5e cable and offcourse made sure the Ns2 has the PoE injector working

This way the wrt54g is transparant and acting as a bridge.
and you can connect 10 laptops/clients to you boatnetwork
, without having to worry that your WISP going to know you are actually connecting more clients to the connection you are using.

Hope you can figure it out...

Jeroen

[Matt Holmes]

I believe this old thread is the best place to pose my question:

I am trying to decide whether to go with the nanostation2 or the bullet atop my mast, and whether to add an external omni antenna (~8dbi?) to the nanostation.

Assuming that I won't be able to point the device, and leaving cost difference between the NS2 and bullet aside, will I see better performance from the NS2 by itself, the NS2 + external omni antenna, or the bullet w/omni antenna?

I read a little bit that the NS2 would switch polarizations by itself automatically, so I'm wondering whether the external antenna would do anything for me. And I'm wondering whether the increased sophistication of the NS2 over the bullet will gain me any range.

much thanks,
matt
s/v Syzygy (valiant 40 #201)
www.syzygysailing.com

[Dave-D]

You can use the NS2 with its two
internal cross-polarized antennas
or an external antenna of your
choice--but not both.

I see no advantage to the NS at
all; as you point out, you can't
aim it. Use a Bullet 2 with an omni.

If you want to match the NS rf
output, you'll need a Bullet 2HP.
If you can wait till spring, you
could use the Bullet M2 for 'n'
(and b/g) compatibility.

It's always fun to find a mount point.
If you can put it on the peak, the
only issue might be if you're very
near the AP: your signal might be
far above the shore-side radio. And
the peak plate might shield it.

Consider mounting another Bullet
on a plastic pole on the poop--like
it was a GPS stick. (That might not
'see' an AP if you are tied up below
the edge of the dock.)

Finally, avoid using a really high gain
omni. They have more narrow beams
and with any pitch will produce
erratic signals. Dave

PS: update on Bullet M2--Ubiquiti
says today that they're shipping and
should be available in a few weeks.

[Matt Holmes]

what you say makes sense so I googled for the BulletHP and a) it doesn't come with the PoE injector b) it's just as expensive as the NS2 c) it's not in stock anywhere

is the BulletHP *better* than the NS2? I thought that the NS2 was larger and more powerful, with more features, so why is the BulletHP just as expensive?

Clearly I'm missing something, apologies for my ignorance on these matters, and much thanks for all the advice!

regards,
matt

[Dave-D]

Matt, the basic features are identical. The
NS2 has dual auto-negotation antennas,
but they're useless in an omni environment.

Such as yours.

Are you worried about a $20 PoE injector?
Remember: the PoE unit operates from ac
mains (inverter if you have one). Others
have run directly from ship's battery (but
I'd be sure to add noise suppression).

I would wait a few weeks for the Bullet
M2. High power, 'n' compatible. Will also
be b/g compatible with the 5.1 firmware. Dave

[Matt Holmes]

say I want to power it with the boat's 12V battery bank--can you recommend a PoE device and source for it? Or is it as simple as identifying which two strands of the ethernet cord get the dc power, and splice it into my 12V DC system?

thanks,
matt

[WHT]

you'll loose 2 dB when you connect the Nano to an external antenna, so you would need a higher gain omni, which would have a narrow vertical bandwidth. Your best bet would be a moderate gain omni with the Bullet.

[WHT]

dual auto-negotation antennas, but they're useless in an omni environment.Then why do many people find there is an advantage for some of their customers with the Nano in auto-polarity mode??

[Dave-D]

Matt, a PoE device has four functions:
> it passes the data leads from your
network to the radio, using pins
1,2,3 and 6
> it has a power supply that produces
dc voltage from ac mains and adds
('injects') it on pins 4,5 (+) and 7,8 (-)
also, a Ubiquiti PoE:
> grounds the shielded CAT5 cable
(required for all installations) via
the shield plug/jack to mains ground
> provides basic surge protection for
data and power leads

Some Ubiquiti PoEs also have a reset
button/circuit to remotely reset the radio.

It's easy enough to put cables and
jacks together in a box to act as a
PoE. But you should always have a
proper fuse and provide isolation
from the large noise signals that
generators put on the power lines.

As you know, a mast makes a
wonderful lightning rod. You need
to provide transient protection
for the radio and data signals.

You can buy plain PoE injectors
with transient protection that accept
external dc input.

If you can put this kit together,
you'll have a good PoE system. Dave

[Dave-D]

WHT, I didn't see your post before.
Now I do, I don't understand it.

NS has auto-polarity mode--but
obviously only for its internal
(directional) antenna array.

Matt can't use a directional
antenna because he's on a boat.
The boat moves around in the
water.

The omni I was describing is
the boat's radio--not the AP.
(But of course the AP is omni too.) Dave

[WHT]

say I want to power it with the boat's 12V battery bank--can you recommend a PoE device and source for it? Or is it as simple as identifying which two strands of the ethernet cord get the dc power, and splice it into my 12V DC system?Its not too hard to imagine the voltage spikes on a marine 12 volt system would be too different than an automotive system. I'd have to look up the specs again, but it quite high. over 36 volts I seem to recall and any device into the 12 volts bus is supposed to tolerate this.

You'll need some 24 volt clamping.

[Dave-D]

WHT that seems something like what
I posted earlier:
<you should always have a
proper fuse and provide isolation
from the large noise signals that
generators put on the power lines>

And you're right on: a marine power
system is much like a car's. Spikes on
starter can go above 100v. Dave

[WHT]

See my original answer two weeks ago

[Dave-D]

Now I am confused, WHT.

Your posts before were about not
using directional antennas and not
using an NS2. So why bring up the
Nano and its (auto-polarity) antennas
again?

Your points about low-gain omnis
were right-on of course. I made
the same points again to Matt.

You didn't post anything before
about generator noise and spikes. Dave

PS: some sailor was using a NS2 tied
onto some shrouds. There was no omni
or external antenna in sight. Nobody
responded then, but I have to assume
he had to re-orient the NS every time
he tied up; useless on a mooring.

[WHT]

So why bring up the Nano and its (auto-polarity) antennas
again?Because many users report they have better success with a Nano, and a few have even provided installation pictures.

Nano on a moving truck - bad idea.
Nano on a parked truck - good idea
Nano on a moving boat - bad idea
Nano on a moored or at anchor boat - good idea

Omni on a parked or moving truck - good idea
Omni on a moored or sailing boat - good idea

Nano with external directional antenna - not as good as a Bullet with directional antenna
Nano with external omni antenna - not as good as a Bullet with external omni antenna
Nano with internal antenna operating in auto -polarity - likely better than fixed

[Dave-D]

All so true and obvious. Except for
the 'boat' part--moored or at anchor.
Boats swing on their anchors
or moorings 180deg with tides.

So in the single case of a boat against
the dock and not bobbing, the NS
might do a bit better. But that's not
what we're talking about, and that's
not what you said in post #2:

'using directional antennas on a [small]
boat is problematic.... ...go with a Bullet'

Dave

[Matt Holmes]

dave,
perhaps I can bridge the gap in understanding: a boat at anchor (or on a mooring) is generally pretty stable and pointed in the same direction--at least for the duration of an internet session. So it is possible to aim a directional antenna while one is at anchor.

Some cruisers do this by hoisting the device with one line and using another control line to spin it properly. Other cruisers mount it low enough that they can reach and turn their directional antenna.

That said, I'm looking to put an omni antenna on top of the mast so that I don't have to aim the antenna every time, and still get great reception.

However, I still don't understand why the NS2 isn't better for me than the bullet, since it has a higher transmitter power, is easier to obtain, and has the option of both internal or external antenna.

thanks to all,
matt

[Matt Holmes]

Also, although it may be easy for you guys to identify poe injectors that will take 12v input and give the right output, I'm having a hard time figuring out if they will work.

for example:
http://www.witelcom.com/index.php?page=shop.product_details&flypage=&product_id=123&category_id=10&option=com_virtuemart&Itemid=32&vmcchk=1&Itemid=32

this says 12v input but only .83A output at 48V, which isn't enough amperage right? And does it need to be a DC-DC converter to push it up to 48V or can it be something that just passes through the 12V?

(oh, and regarding the voltage spikes, I have a voltmeter easily visible in the boat and we don't experience voltage spikes like you mentioned)

thanks again,
matt

[Dave-D]

If you want the hassle of pointing your
radio (and likely re-pointing it with
changing tides), an NS2 would be OK, Chris.

But read WHT's post #2 here, where he
makes the argument for a Bullet.

If you're going to put the antenna at the
peak, I've already described some potential
problems. One I didn't describe is the
antenna cable. The NS is a bit bulky to put
up there, and I'm guessing you want it down
on the deck so you can play with aiming it
as well. But that long cable up the mast will
lose most of the signal. Not a good idea.

A Bullet is small, mounts directly to an N
connector omni antenna a the peak. You would
run CAT5 up the mast, resulting in no rf losses.
Also its rf connector is far more rugged; an
N connector is beefy compared to an SMA.

This isn't about high transmit power; you're
looking at distances under 200m.

But it seems you're determined to buy an NS2.
Why not buy both--they're cheap. Dave

[Dave-D]

That PoE injector you discovered is
neat, Chris! It has some great applications--
but probably not for you.

The input is right, but the 48V output will
fry any Ubiquiti radio instantly. You could
use it by adding yet another Ubiquiti item:
'instant 802.3af adapter', which converts
the 48V to 18V at and for the radio.

Yes, you can use 12V directly from ship's
battery. That requires the pass-through
PoE I already described, with a proper
fuse and transient protection.

Sorry, if you have engine starter motors
and generators, you have transients. A
voltmeter will never show these; they
last milliseconds--much too fast to register. Dave

[panamasteve]

No wifi on the boat in the early 90's, but do have some comments:
1. You won't see the spikes on a regular volt meter, they are too quick. A peak-hold meter will show any problems. If your house bank is isolated from your alternator when starting the engine or generator, you generally will not have spikes. To be save, use a CAT5 surge device that will clamp at 24v on the output of the POE injector. We always disconnected the house bank when cranking the engine (Perkins 4-107) and didn't reconnect to the alternator until the engine had warmed up.
2. Looks like you have nice radar arch on the stern. Couple of things. You have plenty of room at the stern on the arch to mount a BulletHP and omni antenna. 6dB gain max. You want a lower gain antenna to provide increased beamwidth to compensate for the roll of the boat. Omni, because your gonna swing while on the hook. Try watching TV with a directional antenna mounted on the stern...you are constantly adjusting the antenna to maintain a picture. One caveat, if the radar is on, it is pumping out a tremendous amount of RF in the vicinity of the AP. Not sure of the effects on the radio in the AP, but at least don't run the radar while you're surfing the internet.
3. You can attach to your house bank for the 12v to run the AP. As long as your CAT5 run isn't too long. Make sure your POE is fused and surge protected.
4. Take all corrosion protection steps possible. Your putting electronics in absolutely the worst possible situation for corrosion. If you want it to last, it has to be sealed airtight, and I don't think any Ubiquity product(as shipped) is air tight.

(formerly) S/V Miss Kate

'36 Morgan Out-Island
Also, although it may be easy for you guys to identify poe injectors that will take 12v input and give the right output, I'm having a hard time figuring out if they will work.

for example:
http://www.witelcom.com/index.php?page=shop.product_details&flypage=&product_id=123&category_id=10&option=com_virtuemart&Itemid=32&vmcchk=1&Itemid=32

this says 12v input but only .83A output at 48V, which isn't enough amperage right? And does it need to be a DC-DC converter to push it up to 48V or can it be something that just passes through the 12V?

(oh, and regarding the voltage spikes, I have a voltmeter easily visible in the boat and we don't experience voltage spikes like you mentioned)

thanks again,
matt

[Dave-D]

Excellent comments, Panamasteve.

But a peak-hold voltmeter won't show
noise and voltage transients. You can
only see them on an oscilloscope.

Isolating battery banks is a fine idea,
but it requires superior discipline for
what can be ignored with good surge
suppression.

WiFi radios should never be placed in
the close beam of a radar--on or off.
You could literally pop some parts.
And you may see interference even
when radar is in the general area.

'...you're gonna swing while on the hook.'

As always, the ocean hates electronics. Dave

[Matt Holmes]

wht, you're link on post #2 didn't through for me, can you repost? thanks!


Go with the Bullet and an external omni unity or low gain antenna. Better yet, the Wfi Plus discussed here http://forum.ubnt.com/forum/viewtopic.php?t=7022&highlight=

[WHT]

An analog voltmeter, especially one with a damped movement for vibration prone use, won't show any spikes. It takes a 'scope to see a one millisecond spike.

http://www.witelcom.com/index.php?page=shop.product_details&flypage=&product_id=123&category_id=10&option=com_virtuemart&Itemid=32&vmcchk=1&Itemid=32 is a Laird Technologies PoE device.

Its an unusual variation of their regular product line. Instead of a AC power jack, it has a screw-down terminal block. Reading the PDF, it takes a DC input voltage between 9 and 36 volts and converts it to a fixed 48 volts DC output.

This is NOT what you want, its a 48 volt output.

Do they have a 12 to 24 volt output version?

[Dave-D]

Chris, that link was dumped by the forum.

Here are the antennas:
http://www.wifi-plus.com/antennas/24ghzantennasspecs.html

I believe WHT was talking about the 'mesh'
omni in the middle of the page--but he can
fill you in on that. Dave

[Dave-D]

Nice--WHT. Almost word-for-word
what I already posted. Dave

[Matt Holmes]

I think I found one:
how about this one?
http://www.wifi-stock.com/details/apoe02.html

I think the word "passive" is going to be key--assuming that means no ac-dc transforming or even dc-dc converting is going on

[Dave-D]

Sure--passive is the right word.

You could also make one very
easily with a couple of jacks in
a jack box.

But again: this kind of PoE injector
has no transient protection and
no fusing. You need to add those.

A dc-to-dc converter like the one
you found before would be better
because it accepts a wide range
of input voltage (from the battery),
and generates a regulated, stable
output. As WHT asked, if you could
find one with a 15 to 24v output--
suitable for the Bullet--it would be
a better choice. Dave

PS: this is really a very simple project.
Are we drawing this out too much for
you--or do you just like to research?

[WHT]

Nice--WHT. Almost word-for-word
what I already posted. DaveIn reference to what? The voltmeter? I started that post 2 hours ago, but got way layed and finally submitted it just now. I sense an agenda here. The few times I have commented on your posts were to make corrections in fact.

[WHT]

wht, you're link on post #2 didn't through for me, can you repost? thanks!Try this new post. http://www.ubnt.com/forum/showthread.php?t=14959

[Matt Holmes]

it may be a simple project for you--but you do have "ubiquiti specialist" listed next to your name!

Yes, it will be possible for me to make one of these myself, once I figure just a few more things out. I don't know what a "24V clamp" is, i.e. I don't know how to wire in transient protection (or how to find the correct product online). Fusing no problem. And if the bullet requires 15-24V as you mentioned (I didn't know that) then I will indeed need a dc-dc converter since I can't just patch 12V into the ethernet cord--not just a few jacks in a box in that case!

best,
matt

[Dave-D]

Sorry, didn't mean to be patronizing.
It's just that we've had a lot of posts,
and I'm not sure we've got your answer.

Bullet will work as low as 10.5v, Matt.
Sometimes a battery will fall below
that, if it's weak and you're starting.

A 24V 'clamp' is usually a Zener diode--
you can find them at Radio Shack. But
it may be more arduous than fun to
piece this together....

I'd consider finding a local friendly ham
radio guy to do this for you.

That's why a dc-to-dc converter PoE
would make sense: it should have all
this 'stuff' in its design.

I looked at WHT's re-post on those
antennas, and it's not clear to me which
antenna he's suggesting. You might
ask again about an omni antenna. Dave

[WHT]

Requires 15-24V as you mentioned (I didn't know that) then I will indeed need a dc-dc converter since I can't just patch 12V into the ethernet cord--not just a few jacks in a box in that case!

Clamping means it "clamps down" or blocks anything past a certain voltage.

All the Laird/Pacific Wireless products at http://www.witelcom.com/index.php?page=shop.browse&category_id=10&option=com_virtuemart&Itemid=32 look like 48 and 52 volts out. You might want to search the Laird website to see if they have a 15 to 24 volt version of http://www.witelcom.com/index.php?page=shop.product_details&flypage=&product_id=123&category_id=10&option=com_virtuemart&Itemid=32&vmcchk=1&Itemid=32

You can certainly build your own PoE injector (a simple injector lacks the power supply component) using home improvement store or Radio Shack parts - plastic box, faceplate, and two 8-pin ethernet jacks. But it won't have the protection on the individual ethernet pairs, which may not be necessary, nor would it have the 24 volt clamping or limiting on the power pairs lurking in your boat's 12 volt power grid.

[IslandTime]

Matt, here's a page full of POE's from Titan Wireless (http://www.titanwirelessonline.com/SearchResults.asp?Cat=5). The passive poe's are the ones you are interested in. I like the top one. These or similar ones can be found at a number of suppliers by using google.

While there is nothing wrong with clamping your input voltage and using surge protectors, I've been providing systems to boats for the past 3 years using LS2 boards and now Bullets without any failures that can be attributed to spikes or surge. All are running off of ships 12 volts without any protection other than fusing except for a couple using AC/DC and a couple with 24 volt systems that are using DC/DC converters to drop to 12 volts.

Bob Stewart
IslandTime PC

[WHT]

A 24V 'clamp' is usually a Zener diode--
I've never seen any thing use a Zener for this type of discussed protection. They use metal oxide varistor (MOV) disk.

[rmichael]

For power supply try this:

automotive grade DC-DC power supply:
http://www.mini-box.com/DCDC-USB

passive DC injector:
http://www.streakwave.com/Itemdesc.asp?ic=POE%2DINJ%2DLED&eq=&Tp=

pigtail with screw-down terminals to connect the two:
http://www.brickhousesecurity.com/dccord.html?zmam=85491576&zmas=1&zmac=2&zmap=DCCORD

[rmichael]

I've never seen any thing use a Zener for this type of discussed protection. They use metal oxide varistor (MOV) disk.

Both of you are correct:

http://www.littelfuse.com/data/en/Application_Notes/an9768.pdf

It's an interesting topic to say the least :)

[Dave-D]

Matt, here's a passive PoE injector
with transient protection I like so
much I use it myself:
http://www.l-com.com/item.aspx?id=23379
It uses a combination of gas tubes,
zener diodes and reverse-diodes for
its protections. There may even be
a MOV in there somewhere.

Rugged, metal-cased, shielded.
Not cheap at $45, but saves building.
I would still use an automotive audio
type noise filter in series with the
12v from the ship's battery. Dave

WHT: Zeners are commonly used in
transient/overvoltage protection.
Look at Ubiquiti radio dc inputs for ex.

[Full Power]

thank you jeroenimo....what you have is pretty much what I want to do...I am hoping that a bullet2 with a homebrew omni antenna and connected via ethernet to a netgear wg102 will work. Figuring out all the networking settings for the units is where I am pretty weak and still learning...
No need for dramatic over-engineering.

A simple solution gleaned from the thread that would solve the voltage problems and also compensate for any long CAT5 runs would be to use these two devices together to power the bullet. 16 watts availabe will be sufficient even for the HP unit at full power. I would go with the HP unit set for 25 dBm output, connected to an 8 dB omni for a real nice station that will have more than adequate power to communicate with any legal powered host access point you encounter.

http://www.witelcom.com/index.php?page=shop.product_details&flypage=&product_id=123&category_id=10&option=com_virtuemart&Itemid=32&vmcchk=1&Itemid=32

http://ubnt.com/downloads/instant8023af.pdf

[Dave-D]

Full power, see my post #28, where
I explained this exact scenario.

Not dramatic over-engineering,
but probably over-engineering, because
he only needs 12V, and these items
together add $60 or more.

And neither adds transient protection
for the CAT5 run. Dave

[rmichael]

Matt, here's a passive PoE injector
with transient protection I like so
much I use it myself:
http://www.l-com.com/item.aspx?id=23379
It uses a combination of gas tubes,
zener diodes and reverse-diodes for
its protections. There may even be
a MOV in there somewhere.

Rugged, metal-cased, shielded.
Not cheap at $45, but saves building.
I would still use an automotive audio
type noise filter in series with the
12v from the ship's battery. Dave

WHT: Zeners are commonly used in
transient/overvoltage protection.
Look at Ubiquiti radio dc inputs for ex.

>60V clamping voltage... nice for lightning protection but does not protect against load-dump voltage.

[Full Power]

And neither adds transient protection
for the CAT5 run. Dave
Do you refer to this ?.....

Device #1 Load regular percentage: 5%
Line regular percentage: 1%
Ripple percentage: 1.5%
Noise percentage: 3%
Total power: 16.8W
Ripple and noise bandwidth: from DC to 20MHz
Terminated with 47uF capacitor and 0.1uf MPE capacitor of proper polarity
Efficiency: 85% min at 12V/24V DC, input at F.L
Short-circuit protected output
Short GND terminal to prevent damage to power supply

Device #2 Ethernet ESD/Surge Protection +/-15kV

$60 bux for a plug and go solution is a problem, compared to hours of cobbling $150 worth of parts together ? :ihih:

Exactly how much more money do you figure this rich old man cruising around on his 3/4 million dollar boat should spend to further protect a $79 radio ?

[Full Power]

Full power, see my post #28, where
I explained this exact scenario.


A simple solution gleaned from the thread...
Not specific enough ? C'mon dude.

[WHT]

WHT: Zeners are commonly used in transient/overvoltage protection.
Look at Ubiquiti radio dc inputs for ex.But outside the scope of my comment as I clearly specified.

I've never seen any thing use a Zener for this type of discussed protection.,where I was discussing external protection for power supply.

[WHT]

Matt, here's a passive PoE injector with transient protection I like so
much I use it myself: http://www.l-com.com/item.aspx?id=23379
Clamps at 60 volts. Not good 'nuff for UNBT gear.

[Dave-D]

WHT, you're the guy who says 'don't
bother' with transient protection
in most cases--not worth it.

And you're wrong: this unit clamps
data at 15v [wire-to-wire] and 80v
for power. Max. power voltage is 60--
which is exactly right for use
with 48V PoE sources. Dave

[Dave-D]

'Discussed protection' was transient
and over-voltage (such as you
typically see during starting).

As you quoted me, WHT, '24v
clamp' is exactly what the Zener
is used for in the power input
circuit for Ubiquiti radios. It
protects against PoE overvoltage. Dave

[Dave-D]

Hey 'full power'--it's great when
you 'glean' from the thread--
infer/put together/imagine.

You repeated exactly what
I said. That ain't gleaning, dude!

And yes: I referred to those
exact same devices. I think it's
a decent solution, so we agree.

I don't know if he's rich, but Matt
is not an old man by any count. Dave

PS: That's also why I suggested
to Matt that a 'dc-to-dc converter
PoE would make sense....'

[Dave-D]

Rmichael, I don't know what you
mean by 'load dump voltage', but
if you're saying this PoE injector
doesn't protect well enough
against power surges in the
ship's dc system, you're right.

It was intended for a nice,
quiet PoE wall power supply.
That's why I said at least a
noise filter should be added
between it and the dc source. Dave

PS: That's also why I suggested
to Matt that a 'dc-to-dc converter
PoE would make sense....'

BTW: that's a great app on transient
protection from Littlefuse! I may add
that to my permanent collection.
Points out that the Zener is best
for clamping because it's so fast, but
is limited by its dissipation. So for high-
energy or long-term clamping, use a
(high-dissipation, slower) MOV (too).

[WHT]

UBNT...is...not...48...volt...PoE.

I have always maintained surge protection is not cost effective for fixed installations. I have always maintained that extra steps are necessary for mobile applications.

[Dave-D]

WHT, of course Ubiquiti radios don't
use 48V power. We can agree.

The solution first proposed by Matt
in post 26 and discussed in posts
28, 36, 47 and 50 was to use a
12v to 48v PoE supply, and a
Ubiquiti 'instant 802.af adapter'
at the radio.

That would put 48v on the CAT5
cable, which (if you choose to
use one) requires a transient
protector designed for 48v.

The protector I pointed out has
good data lead protection (15v
clamping) and good power lead
protection (80v clamping). It's
ideal for this application.

Do you agree? Dave

[Dave-D]

-WHT, this got shuffled away in
the posts:

Please take a look at Matt's post
#31 where he asks about those
omni antennas you linked to,
and my post #33 where I gave
him the link (and called him 'Chris'
by misteak).

I wasn't able to point out the
exact antenna you proposed,
because your original link was
lost. Thanks, Dave

[Full Power]

Hey 'full power'--it's great when
you 'glean' from the thread--
infer/put together/imagine.

You repeated exactly what
I said. That ain't gleaning, dude!


Device #1 was first posted by Matt Holmes in #26, page 3. for example:
http://www.witelcom.com/index.php?page=shop.product_details&flypage=&product_id=123&category_id=10&option=com_virtuemart&Itemid=32&vmcchk=1&Itemid=32

Which was followed by your reference to device #2 in post #28. This alone should qualify my "gleaning" comment to be accurate, true and valid. Furthermore, it was myself in post #47 ( page #5 ) that specifically identified product #2, thanks to your prior reference in post #28, page #3.

And "Chris" seems to be a mis-post by you as you have subsequently corrected ( therefore my lack of specific post # reference ). For further thread posting ID and clarification I have compiled a player's list as follows... ( My apologies again for not making a more formal introduction sooner )

George ( Capt. Folly, the OP ) Introduced to the thread at Post #1
WHT ( WHT ) Introduced to the thread at Post #2
Bob ( IslandTime ) Introduced to the thread at Post # 3
Jeroenimo ( Jeroenimo )Introduced to the thread at post # 8
Matt ( Matt Holmes ) Introduced in the thead at post # 10
Dave ( You, Dave.D ) Introduced in the thead at post # 11
Steve ( PanamaSteve ) Introduced in the thead at post # 29
rmichael Introduced in the thead at post # 44
Jim ( Full Power ) Introduced in the thead at post # 47

I've mentioned before, I'm new here, but doing my best to climitize and fit in as best I can. I really appreciate your insight and contributions. I have a lot to learn about Ubiquity and I for one really appreciate the information found here in the forum, and in particular your insight !
:ubnt_banana: :ubnt_banana: :ubnt_banana: :ubnt_banana:

[Dave-D]

Sorry you felt you had to document
this so completely, Jim. I should
have ignored the whole incident
and focused on the technology. Dave

[Full Power]

Sorry you felt you had to document
this so completely, Jim.
Quite alright Dave. I can tell that you and I possess and value the same objective ( helping our fellow nerdz with the finer details ). FYI I have a rather extensive background in electronics, computer systems and implementation, and radio electronics in particular. Be that as it may, we seem to consistently arrive at very similar conclusions for any given project, and deliver approximately identical advice for configuration scenarios. Consequently I can only deduce that you are of a similar, and at minimum, technical back ground as myself.
You do seem to have a penchant for details, and in my current and most normal state of mind ( plastered to the gills ), I was only trying to be as acceptable and helpful as my advice can pertinently be. I harbor no malice towards anyone, nor participate in any pissing contests.

So, when are you gonna fly down here to my neighborhood so I can treat you to a cross-border party of yer life ? The least I can do is ( and happily will ) buy a round of shots for the whole house, as soon as the next boat load of gear arrives from China !!!! :icon_twisted:

[rmichael]

Just wanted to say-thanks eveyone for posting. Everyday I learn something new here.

[Matt Holmes]

bob and dave, much thanks for the specific links, I feel like I'm about ready to buy my equipment. Current plan is to search a bit more for a reasonably priced PoE with transient protection, and if I can't find one then I'll put it together with one from the Titan website that bob provided and take my chances with voltage spikes.

dave, I noted in the specs for your most recent PoE link that the powerclamping is at 85V (as mentioned by one of you other overly excited folks).

The BT-CAT5-P1J is a lower voltage version of the device you posted (also cheaper at $35) and as an added bonus provides some noise suppression:
http://www.l-com.com/item.aspx?ID=23845

In the datasheet for this one it talks about clamping at +/- 58V, so the question for the experts: is +/-58V enough transient protection for the Bullet (or NS2, whatever)? Or is it insufficient (and thus pointless)?

thanks,
matt
ps I'm 31 and not remotely rich
www.syzygysailing.com

[Matt Holmes]

'Discussed protection' was transient
and over-voltage (such as you
typically see during starting).

As you quoted me, WHT, '24v
clamp' is exactly what the Zener
is used for in the power input
circuit for Ubiquiti radios. It
protects against PoE overvoltage. Dave

wait a minute, just saw this, are you saying that the NS2 already has built in overvoltage protection of the type being recommended here?
thanks,
matt

[Dave-D]

Matt, Ubiquiti radios have absolute-limit
over-voltage protection. I wouldn't rely
on it for the main protection. Dave

[Dave-D]

C'mon Matt, I know you're on a budget.
But this unit is $10 less than the good
one. It has 58V protection on the data
leads instead of 15v. IMHO not nearly
good enough.

This is the kind WHT thought he was
panning.

There is no 'added bonus' noise
protection. It's identical to the one I
recommended; has shielded jacks. Dave

[Matt Holmes]

dave, unless I'm missing something, the link you provided and the link I provided point to the same unit only in different voltage versions. Let me know what I'm missing:

your link:
http://www.l-com.com/item.aspx?id=23379
my link:
http://www.l-com.com/item.aspx?ID=23845

the cost was not the reason I pointed to the other device, rather the fact that it appears to have a lower voltage cap for transients

[Dave-D]

No, Matt--very different design. Use 23379. Dave

[Mad Dog Voyager]

Hello all,

This has been a very interesting thread. We've just gotton our Bullet M2HP and are planning the install. I was going to ask about PoE's but... rather than flame the fire I read the entire thread instead. :icon_smile:

A question came up though about the antenna. Maybe this isn't the best thread, but it's about WiFi on a boat so here goes. Rather than a 6 or 8.5 dBi antenna, what if you were to use 3 120 deg Directional Sector Antennas (9 or 12 dBi) connected through a 3 way splitter box (similar to http://www.l-com.com/item.aspx?id=20861&cmp=ALSOS).

There may be a great technical reason this wouldn't work, but I'd be interested to hear your opinions.

Regards,
Dean
s/y Mad Dog Voyager
www.TheMadDogs.com

[Dave-D]

Hey, Dean!

What, no flame? How boring; you didn't try
very hard!

Your scheme would work as you describe it,
but you will easily see that it logically has
no benefit--and three huge deficits.

First, if you split a signal into three parts,
each part provides no more than a third
the available power to each. One sector
gets only its third.

Second, all that extra 'stuff'--including the
splitter, the connectors and the cables--
takes an extra toll on signal, due to all
kinds of internal losses.

Finally, this will cost a bundle.

If your object is to increase the omni's gain,
you could easily install a 12dBi omni. But
that gain comes at the expense of vertical
beamwidth. At anchor, the beam could easily
overshoot most shore-based APs. And as the
vessel tosses, the narrow beam will often
miss the AP--at any elevation. That's why
only a moderate-gain omni is specified
for most mobile applications. Dave

[WHT]

Lets say you had a 21 dBm transmitter power output (TPO) connected to a 15 dBi omni antenna. You'll have 36 dBm EIRP. (EIRP is legally limited to 36 dBm for omni PtM use, so you need to back down your TPO to 21 dBm)

Now lets take an antenna splitter ($50) with three 14 dBi sector antennas ($150 each). Set your transmitter for 24 dBm TPO and divide it by three ways. So each antenna is getting only 8 dBm. Add that 8 dBm to the antenna gain of 14 dBi, and you get 32 dBm EIRP (actually a little less as you have the splitters internal loss).

So now you have spent $500 and have an array that's 4 dB less EIRP, compared to a $115 omni http://www.l-com.com/productfamily.aspx?id=6414 solution.

[Ron]

Dean, the clever solution is to get 3 sectors and connect each sector to it's own bullet. Connect the 3 bullets to one router and have the router dynamically pick whichever sector has the best signal strength.

Of course, this is the sort of thing we charge a few thousand to setup.

[WHT]

But wait...there's MORE!!

If you order NOW!, we'll program in NAT tables for an IP coffee make...

[rmichael]

Or, just get an AP with beamforming antenna.

[Mad Dog Voyager]

Hmmmmm, and while we're at it, let's set up a KVH Broadband Satellite system on the boat.... then we won't have to worry about WiFi anything.....

At least it's confirmed that there was a reason to ask the question.

And now returning back to earth for a moment, what about the omni antenna then? I currently have a MaxRad 6dBi antenna that I was looking to connect to the Bullet. I know it won't be as strong as a 9 dBi omni, but how much more range (read satisfaction) could we expect from something like a Pacific Wireless OD24-9 (this one has a 14 deg beamwidth).

How would it compare to a 7.7 dBi such as http://www.wifiandmore.com/antennas/2-4ghz/comet-antenna-sf-245w/prod_76.html (this one has a 20 deg beamwidth)

Thanks,
Dean
s/y Mad Dog Voyager
www.TheMadDogs.com
Exploring to inspire...

[WHT]

For every 6 dB of gain, you double your distance.

6 dBi omni compared to 7.7 dBi sector would have very little advantage.

[Dave-D]

Dean, I hope you're having fun already!

You know the omnis' vertical beamwidth,
so you can easily see the effect of motion.
A 14dBi beam will allow you +/- 7deg of
motion and the 20deg will give you +/- 10deg.

If you're lashed to the dock in a quiet pond,
it won't matter. If you're on a mooring in an
exposed bay, it will make a big difference.

Or, if your mast-head antenna is high above
the AP, you could overshoot it if you use a
narrow-beam antenna--even with no motion.

That's why only a moderate-gain omni is
specified for most mobile applications. Dave

[Ron]

Or, just get an AP with beamforming antenna.

Know one that actually works well?
Do share.

[Ron]

Hmmmmm, and while we're at it, let's set up a KVH Broadband Satellite system on the boat.... then we won't have to worry about WiFi anything.....

KVH Broadband Satellite is only 2 Mbps at the very maximum.
WiFi is far faster (also cheaper, obviously).

[WHT]

Not for under $5,000.

[Mad Dog Voyager]

Dave, you gave me some things to think about and how to reconsider the appraoch.

On another topic - and totally off of this one - you were discussing with Matt Holmes about a clean power supply. In addition to clean power for the Bullet M2HP, I also want to have clean power for a couple of external hard drives (to save all the good stuff downloaded via the Bullet). In order to be power conscious in our plan to sail around the world, we need to convert as many 12v appliances & devices to run off 12v direct.

It sounds like we could build one of these, but I want to be able to step-up or -down the voltage as required to deliver "pure & clean" 12v.

Any suggestions on either the "buy or build" trains of thought?

Thanks again,
Dean
s/y Mad Dog Voyager
www.TheMadDogs.com
Exploring to inspire...




Sorry, didn't mean to be patronizing.
It's just that we've had a lot of posts,
and I'm not sure we've got your answer.

Bullet will work as low as 10.5v, Matt.
Sometimes a battery will fall below
that, if it's weak and you're starting.

A 24V 'clamp' is usually a Zener diode--
you can find them at Radio Shack. But
it may be more arduous than fun to
piece this together....

I'd consider finding a local friendly ham
radio guy to do this for you.

That's why a dc-to-dc converter PoE
would make sense: it should have all
this 'stuff' in its design.

I looked at WHT's re-post on those
antennas, and it's not clear to me which
antenna he's suggesting. You might
ask again about an omni antenna. Dave

[WHT]

http://powerstream.com/ may have some ideas for 12 volts.

The higher the gain the antenna, the flatter the pattern The flatter the pattern, the more sensitive the antenna is to tilting. For that reason, you'll find public safety data antennas are a small three or so inch radome stub, usually 3 dBi gain at most..

The Pico 2 with its 6 dBi attached antenna or a Bullet 2 with 2.4 GHz 7 dBi Rubber Duck Antenna http://www.l-com.com/item.aspx?id=22064&cmp=ALSOS or 2.4 GHz 2 dBi Rubber Duck Antenna http://www.l-com.com/item.aspx?id=22051&cmp=ALSOS Hang the PCV sleeve with a nylon cord from the top to keep it level.

This would be a good solution for salt water marine use. Stick the whole thing in a length of PVC pipe and seal it with a polyurethane glue, not silicone glue which will delaminate from plastic. I use a concrete/masonry glue from Lowes. http://www.stickwithpl.com/Products.aspx?ID=Polyurethane-Concrete-Masonry-Sealant

[Mad Dog Voyager]

Thanks,

Back to the PoE discussion...

Another thought came up after browsing another thread. As this thing will be in a sal****er marine environment, I want to seal up the Bullet, connections, etc. If I do this and need to "Reset" the thing, I don't want to go through the process of "unsealing and ungooping" the whole thing. Is there a PoE that I can use that will allow the Bullet to be Reset from the PoE?

Dean

[Dave-D]

Dean, if I were fitting out a boat for cruising
and wanted to be absolutely sure I had clean
12Vdc, I would probably build up a unit from
dc-to-dc block power supplies. And WHT has
listed one of several sources, but they tend
to be very pricey when ready-made.

Not all devices are fussy of course, and if you
want to provide clean power to high-energy
equipment, it will cost a lot more. Be selective!

For the remote reset, the new 'M' series radios
have a remote reset circuit which can be triggered
by the newer PoE supplies, which have a reset
button built-in. This is a recent change-over, so
you may have to shop for the right PoE device.

For the 'un-gooping' part, I would use threaded
PVC tubing hardware instead. It's water-tight and
you can easily disassemble it. Dave

[WHT]

Just float charge a 12 volt battery directly off your 12 volt buss. They make great filters.

[Dave-D]

Twelve-volt batteries make great filters--
for low-frequency noise. They're not great
for rf noise at all. They need bypass... Dave

PS: rf noise comes from motors, brushes,
switching contacts. Starter motors, winch
motors and wiper motors are excellent.

[LeoL]

We have used both the Bullet2 and Nanostation2 on our sailing yacht for over a year, testing them in many anchorages and ports. The Bullet had an 8db omni, and the same omni was also tested with the NS2 as an external antenna. The best results were always with the NS2 internal antenna (adaptive mode) but with the caveat of sometimes having to reorient it quite often when swinging at anchor (mounted on an telescopic pole on the transom). In many cases we could not at all connect with the omni, so it was a case of either nothing or putting up with the rotating agravation. The issue of directional versus omni does not only depend on signal strength (and distances) but on interference from the multitude of access points found in some harbours (I have seen up to 40 access points listed at once in the NS2 site survey). Remember that there are only 3 non interfering channels available (1-6-11 in USA or 1-7-13 in Europe) so the directional NS2 antenna is very usefull for eliminating strong interfering signals coming from the back or sides. Often the non-encrypted signals are the weaker ones. In remote places with fewer and weak signals, the NS2 would often connect when the Bullet could not. If the signal is very strong, the NS2 will often connect even if not pointed the best direction, perhaps because signals reflect off metal structures and bulidings. If you plan to use paying access, the signals of which tend to be strongest in many ports, then the Bullet/omni might work well enough. For 'free access', we usually need the NS2.
I would personally not choose to mount either at the masthead, because of the vulnerability to lightning and hard access; but perhaps on a spreader half way up. The height is somewhat beneficial for long distances (to get the fresnel zone off the water surface) or to 'see above' neighbouring motoryachts in a marina. Our transom pole can extend from 12ft to 18ft above the water. Adding the extra 6ft sometimes helps with distant signals. A Bullet/omni at the masthead might be worth it in remote places where the signals are few and weak, but then perhaps the extra range of the NS2 (internal) at a lower mounting would do just as well. An NS2 with a rotator at the masthead would do even better, but might prove technically unreliable.
Some boaters use a higher gain omni on the Bullet (up to 20db; but beware of the vertical angle). This helps alot, except where there is interference which then also gets stronger.
LeoL