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[Ham-80211] Fw: Providing Long-range Wifi

Chriswlan2 chriswlan2 at linnixislands.com
Tue Aug 28 21:16:22 UTC 2012


Chriswlan2 wrote:
> Hi Bob, sorry for the delay: not quite retired and 10 hours west of
> GMT... 
> 
> I spent lots of time learning the ubnt world by myself last year, and
> it is a steep learning curve, when from scratch. Countless hours
> digging around the web. Love/hate relation with ubnt: they constantly
> come up with new wonderful features, patches for weird bugs, and the
> docs are far from all inclusive. Lots n lots of great features for a
> cheap price. The mechanical plastic housing of the Bullet etc is
> flimsy etc... as everything nowadays. Depending on how you price your
> time you may wish a Bullet cost $500 and more!
> 
> By the way, there is a thread going on somewhere at the moment re
> using "sort of wifi" commercial gear on 70cm: better in trees, but
> less bps... 
> 
> Concerning being outside the std wifi edges, while ubnt is quite wide
> band many gain antennas are not, some have confusing specs, but some
> bbq grid and some panels are rated 2300-2500.
> 
> ubnt's, at least bullet etc use nice plain POE, and I run mine on
> plain unregulated 12V. In my case I made a 3-way custom harness, long
> enough to use with the painter's pole, to test new sites. Same
> harness is dandy at the test bench. PowerPoles I find a bit flimsy
> but adequate. I make little portable batteries out of 2 Panasonic
> 6V-12A, taped together, with at least TWO PowerPoles on each, so that
> I can swap in fresh batts without disrupting the radio; or daisy
> chain more of them etc. The 6V-12A are the most Whr for the buck.
> Have a fleet of these to get running ASAP, while solar PV n gennies
> can be sorted out. 
> 
> ubnt's have a very good built-in web access: have your portable
> cabling ready for plugging a netbook ( with expensive satin screen to
> reduce glare) to use the scanning functions, etc, when setting up.
> Reported signal strength seems to be rather accurate, even when
> testing different antennas. In my case I find a 10 dB margin a bit
> iffy, but am usually happy with 15+. I run the links at 5Mbps only.,
> for better DX! I'd guess you'll loose lots of signal strength when
> you do video etc. Could even have a cheap Voip phone part of the
> permanent portable set up, as a private intercom, to help
> coordinating the setting up... If 2 meter is busy with emerg stuff...
> Thinking of it!...  Anybody in the emerg industry is including "wifi
> voip  
>> telephone patch< "   in their modern versions? I'd think your
>> Officialdom 
> customers in the bush site would love to call their office on their
> "real" POTS number? Or call FEMA in DC?     :-)
> 
> Re: the annoying 5VDC well regulated wall warts: I've begun throwing
> them all in the garbage. And popping all those fancy gadgets open to
> solder in one of them tiny inexpensive DC/DC converters, so that said
> gadget will now have a PowerPole pigtail that accept unregulated
> plain 12V! Darn it! How dumb are designers nowadays....  Thinking of
> a cheap LAN switch for the VoIP above...
> 
> Oh and yes, no PC or anything else required for the system in running
> mode. You can also completely set all parameters remotely,  on any
> node at any time, over the air, without any shut down, (except when
> that one unit is rebooting) from the comfort of your office: careful,
> think THRICE before clicking "Apply", as it is easy to lock yourself
> out of that remote unit! Requiring a hike up that mountain...
> 
> 
> Robert Dixon wrote:
>> Christian - Thanks for the good comments.  Having the capability for
>> an intermediate relay point is a good technique to have in our bag of
>> tricks.
>> 
> 
> To make the expense easier, not having 2 full-fledged portables, may
> be have a Mr Heavy portable designed to also carry a lightweight Mr
> Satellite, in a big box,  if it is on a trailer? Satellite would be
> quite light weight (water pipe, surveyor tripod), ready for use, just
> in case. And as well, depending on the circumstances, (ie trees) the
> one or the other could be used at the end site.....     ? It is
> common to have at least one of the 2 sites clear enough that a tripod
> is plenty. Bungy cord- tie a pipe to a farmers fence post...  Or
> sometimes you really, really, need to pack a tripod 300ft up a steep
> embankment, from the pavement... 
> 
> Cheers
> 
> Christian
> 
> 
> 
> 
> 
> 
> 
>> The Ubiquity Bullet sounds wonderful, as it would allow operation
>> just below the wifi band, hence avoiding all the QRM mentioned by
>> others, yet still allowing use of inexpensive wifi antennas.  I see
>> they are for sale new on ebay, including both USA and export models.
>> Presumably one would buy an export model, so it would go outside the
>> wifi band?  Is the included firmware all one needs, and does it
>> operate thru the ethernet cable to the PC?  Or is separate PC
>> software needed?  I looked at the Ubiquity web site but didn't find
>> it completely clear.
>> 
>> Bob W8ERD
>> 
>> On Aug 27, 2012, at 3:20 PM, Chriswlan2 wrote:
>> 
>>> 
>>> My 2cts:
>>> 
>>> 1-Splitting off a minor fraction of the effort on a "secondary" leg
>>> option would tremendously increase the success rate, while lowering
>>> frustrations: have the 24dB portable site fitted with another
>>> antenna to "shoot back" down a great LOS second link into the
>>> target, when it is shaded out by obstructions on the 90ft tower
>>> first link. Many times whenever a direct link has any doubt with it
>>> before starting out, it will be much faster, as well as more
>>> sffective, to drive straight to an intermediary clear location, and
>>> do a 2 leg relay that have great LOSs.
>>> 
>>> 2-I did a 3 mile link with good result, with 20dB panels, although
>>> there was an obstructing hill perhaps 1/3 1/4 the way on the path.
>>> But it was a smooth hill top and "only" perhaps 15ft "too high".
>>> Obstructions that are toward the middle of the path are definately
>>> less trouble; important to keep in mind.
>>> 
>>> 3-I have several links across a flat treed atoll, around 7 miles:
>>> clean "beach to beach" LOS across the lagoon, just grazing the mid
>>> point sea level,  with panels on a single piece of pipe, is quite
>>> strong, but trying to get "inland" from there is extremely tricky.
>>> Doing a WDS relay from an existing nearby "beach" station is so much
>>> more effective. With lots of luck, hours of GPS work, and walking on
>>> roof with a test panel, I once succeeded in feeding internet
>>> directly to a "cafe", accross the lagoon and then on through the
>>> ending half a mile of intermittent coconut plantation; but in this
>>> special instance there was definately a somewhat vague but helpful
>>> notch in the tree line, as seen from the Internet cafe roof.
>>> 
>>> 4-In 3 above, getting UP into the notch, getting a taller pole was
>>> helpful; but "laterally" was quite pointy.  But usually I spend a
>>> few hours with a probing portable telescopic pole, mapping signal
>>> strength, to find the spot, usually only a few feet in diameter,
>>> with the strongest (and hopefully stable in varying wind directions)
>>> signal, and in my atoll situation, "getting higher", mostly never
>>> works. Instead if I have only a very short distance of coconut trees
>>> to go through, at the end of the path, I end up with a panel at 8 to
>>> 15ft ONLY, to go over small brush and small buildings, and UNDER the
>>> coconut crowns. Works fine if I can see through the TRUNKS. Only a
>>> few (moving) coconut fronds, close in, play hell with my links.
>>> 
>>> 5-Ubiquiti 2.4 radios have the option of setting channels 2 MHz off,
>>> "in between", but in busy area probably wouldn't help. But another
>>> very effective step in keeping non-Hams out.
>>> 
>>> 6-Ubiquity affordable radios are really flexible: with the export
>>> f/w, one can choose all kinds of freq above and below the 2.4
>>> "wifi". (don't have US ham allocations in mind...). The "Bullet High
>>> Power, screws direct on to the panel N jack.
>>> 
>>> YMMV
>>> 
>>> Cheers
>>> 
>>> Christian
>>> WO1V




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