Worklog - Air-Stream Wireless 13m Mast

Discussion in 'Modding Worklogs' started by Laggy7, Dec 18, 2013.

  1. repsa

    repsa Member

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    Nice build laggy!!!

    What Throughput you get over the links ?
     
  2. LostBenji

    LostBenji Member

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    Up a tower somewhere....
    Hopefully done better and legally...

    • Illegal mains wiring (both boxes, clear as day)
    • Indoor grade cables, should be Outdoor STP
    • No bonding
    • No lightning protection
    • No RF shields on the dishes to stop cross-talk (those feeders leak strong lobes)
    • Guy wires not terminated properly (saddle clamps wrong way around and needs two at minimum)
    • No sealing done on N-type fittings
    • LMR400 should be LL400 and the radios should be A LOT closer to the antenna
    • You don't stick multiple radios in same metal can
    • Would be interested to see what EIRP is being pushed???
    • Whole lot could have put on a single 30' telo-mast on the house or better still, shed roof without the mess
    So I am guessing you're an F-call and haven't read the Regs?
    http://www.vkradio.org/licence_and_regs.php
     
    Last edited: Jan 30, 2014
  3. nightsky_au

    nightsky_au Member

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    Hopefully You dont end up installing a mast anytime soon too.

    I agree with the mains wiring, That is VERY unsafe, There is no terminal shields on the Live wiring on switchmode and Using a terminal block, Where is the earth wire? It seems RF Earth is the Mains Earth, Very bad.

    Indoor cabling isnt so much of an issue, However with that big building nearby I wouldn't risk it.

    No Bonding, Entirely agree, The Electrical potential could be fatal.

    Lightning protection is useless, If the mast gets hit, You have much more to worry about than the Radios.

    Guy wires are fine.

    RF Armor shields would be pointless seeing how close each dish is to one another.

    N-Types look fine, Only thing i would recommend is some Dual wall heat shrink on the connector where its crimped. There is no point wrappign the whole connector, its a Pain in the ar*e in the future and tends to lead to failure when water gets trapped from not doing it right.

    You wouldn't use LL400, This is a moot point, There is no benefit., LL is lossier at 5.8Ghz

    Radios in same Metal box is perfectly fine, The radios are shielded on board and put out a meer 500mW -+ 200, Same box is not an issue as long as the boards shields are in place. (You will find alot of commercial gear, Motorolla, Airmux etc has the radios in the same box)

    EIRP, 4W, Just because hes done a poor job on the mast doesn't mean hes done a poor job on the RF side. (tho i wouldn't trust)

    You have got to be an absolute idiot to reccomend this gear goes on a telomast, You have to be an even bigger idiot to mount it to a shed roof. The Rocketdish30's weigh about 10kg each, Telomasts are designed for a single antenna, not 4-5 radios weighing 10kg each, the tower would snap in half in the wind.

    Im guessing you are a Standard call and hate F-Calls :)

     
  4. nightsky_au

    nightsky_au Member

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    This is incorrect.

    Into the antenna and out of the antenna (PEP/EIRP) are Different.

    If I put 32W into a 25dbi Gain antenna, It would result in 10kW coming out the antenna.

    You CANNOT Ignore the ERP, Please read the LCD.

     
  5. Blinky

    Blinky Member

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    It's funny that this came up on the front page today, as I was pricing steel for a monopole build for a little wireless relay I need to build.

    I've never done one un-guyed past 4 meters before. Anyone done an unsupported mast @ 10 meters?
     
  6. NymPhD

    NymPhD Member

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    Really? I would lose my job in a heartbeat... No shackle deserves to be treated like that. And the clips are backwards. And the thimble... :thumbdn:

    [​IMG]
     
    Last edited: Jan 30, 2014
  7. Aetherone

    Aetherone Member

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    I've just encountered this exact problem with a Jaycar 12v switchmode PSU - no useful shielding whatsoever around the mains terminals. 240v of tingly goodness is just a firm fingerpress away. :confused:

    I'm hoping a good potting of all three terminals with neutral cure silicone will suffice.
     
  8. nightsky_au

    nightsky_au Member

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    And what do you find wrong with it. Hes used 2 D clamps, Thimble looks fine. The Shackle doesnt look to be in use but thats perfectly acceptable.

    A better closeup is:
    https://imageshack.com/i/1al8kxj

    This looks perfectly acceptable. You will find many towers using Shackles on the guy points, It is common practise in the industry.

    I have put up hundreds of towers, I am also a licensed rigger that climbs many commercial broadcast towers.

     
    Last edited: Jan 30, 2014
  9. Aetherone

    Aetherone Member

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    I thought that was the whole point of the Nanobridges and Rocketdish'es - the radios couldn't get any closer to the antenna :confused:
     
  10. NymPhD

    NymPhD Member

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    OK i'll bite :)

    1) the saddle of the D clips should be over the live side of the termination, U part over the dead end. The ones in your pic are wrong too (although the shackles are right). Ever heard the phrase "don't saddle a dead horse"?

    2)Thimble is in such a position that the load is trying to bend it.

    3) both the welded eye on the pole and the fswr are held on by the shackle pin. this'll put side loading on the shackle. As far as i can tell there's no good reason for it. maybe the wire was cut too long? Would've been better off cutting it a bit short, putting the load in line with the shackle, then using a turnbuckle to take up slack and tension the wire (properly moused of course).

    Not like that ya won't.

    I don't do the telecoms work often, mainly entertainment. But this is like rigging 101 dude...
     
    Last edited: Jan 30, 2014
  11. LeafKickeR

    LeafKickeR Member

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    Uleybury is back up and running, I came over from London to get it back up with GF3 and SquiD
     
  12. LostBenji

    LostBenji Member

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    Up a tower somewhere....
    Look at yourself before you make that comment...

    Building has nothing to do with it, you use STP on any tower or mast to bleed off static and reduce EMI.

    The lightning protection is NOT for the radios knucklehead, its to make sure the tower can take a hit and survive without blowing apart and/or falling on the houses. A strike hits the pole, the cables will carry strike straight inside the house (mains wiring and data).

    I think you need to learn rigging. Others have already pointed out your shortcomings.

    Ubiquiti made them for a reason, they work too. I am not trying to block electrostatic RF, I am talking about the EMR coming off the side lobes.

    Glue-heatshrink does NOT seal to cables or fittings, water will and does get under it. Tape the fuckers like everyone else who wants them to last.

    Again, another silly statement. The OP should be trying to stay in his power limits. Why stick another RF noise source of two inside same can trapping the RF noise while desensing the each other?
    Motorlla is far from an ideal example (Over-priced, under-performing). Plenty of multimillion dollar companies who bring out gear that just doesent work. Airspan comes to mind quickly..

    See below...

    This is an absolute winner comment. I would sack you if you worked for me and made these statements.
    I to work in the industry as a Telecoms rigger and Tech and have done so for over 15 years. I have no less than 350 Tellos up in the wild and haven't lost a single one. Stop showing your ignorance and realize there are more than one way to skin a cat.
    The OP had a cherry-picker so access to pole was easy and no different to how he needs to now anyway. A smart man would have put a LARM on the roof of the shed (I can see the shed wasn't there at initial mess-up time) over a joist and then use the bottom three sections of a 50-footer. This would see a large OD pipe more than capable of holding the gear and more. When a 50 is guyed properly, the force on the base of the pole is in excess of 500+KG's (depending an guy-wire angles).
    As for the F-call swipe, I actually was an F-call myself but as I was also a Radio tech, it would piss-off the Standard and Advanced calls so much that I got sick of the BS on the air and dropped my call. Not my fault if I could stay under my 10W and punch more than 500KM on 2-70...

    If you are going to quote me, please quote the whole sentence and make sure you read it carefully. Go back to the OP and look at the pictures, the poster has put up pictures from several different stages and random order, the comment was aiming at the early setup with the use of passive antennas (Grid-packs) and remote radios. Several meters of coax that didn't need to be there.
     
  13. Blinky

    Blinky Member

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    ... in short, it should look like this:

    http://i.imgur.com/FFSeYc7.png

    :)

    This isn't correct.

    http://i.imgur.com/vRx9pPx.jpg

    NB's have very little rear bleed, apart from that you just split your channels.

    --------------------

    A little less nastiness would go a long way in this thread. Yes there are things wrong with the OP's install, but there are ways of expressing yourself that don't have venom dripping from every word.

    If you guys pointed out the the issues without judgement, it might give the OP a way to access some better info than he has previously had access to. Try to help not hinder. :thumbup:
     
  14. LINUX

    LINUX Member

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    Part 3 section 16 of the LCD states:

    Where does the LCD mention ERP? The LCD doesn't appear to define "transmitter output power", but the wording implies this is a measurement taken at the transmitter, not in front of the antenna. The "subject to section 15" bit is about operation on 6m and 10cm.

    What would realistically limit high power wifi is compliance with EMR regulations.
     
  15. Blinky

    Blinky Member

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    Given the spectrum... Just 4 watts max EIRP.
     
  16. LINUX

    LINUX Member

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    Except the EMR spec would depend on where the antenna is and what it's pointing at, how close someone can get to it etc. Although I'll be honest that it's a bit hard to find good information for 2.4/5.8GHz emissions.

    The WIA posted guidelines here: http://www.wia.org.au/members/technical/emr/

    They state that "Compliance Level 1" requires the ERP to be <3.2kW and the average transmitter output power to be <100W.

    They've also published a document here but it only tabulates safe working distances up to 1.2GHz. For a 20dBi antenna fed with 200W at 1240MHz the safe distance is apparently 16m in the direction of maximum gain. It would be possible to extrapolate that data, and combine it from Table 7 from the ARPANSA EMR standard (listing exposure levels in E and H field strength) to come up with a safe distance for a given wifi installation.

    The 4W ERP wifi limit is imposed both to limit interference and make sure that anybody with zero training won't hurt themselves. Licensed operators (both commercial and amateur) still need to make sure nobody's health is threatened, but when we know that health risks have been managed (eg: the antenna is up a 20m tower with restricted access) higher output power is permitted.
     
  17. Blinky

    Blinky Member

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    This is key to remember when replying, we are talking about the unlicensed spectrums here. This thread is not about 11GHz radio backhauls.
     
  18. OP
    OP
    Laggy7

    Laggy7 Member

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    even i don't un-guy anything over 3m; and use a minimum of 50mm pole with 4mm wall (the wind can do some pretty severe things)

    thanks for your comments & your PM.
    I can understand your objections from your point of view as someone whom works in the industry. I have seen alot of ridiculous dodgey stuff not just on the ubnt forums but here in Adelaide. I have tried to do things as safe as possible and with the budget we have (Lack of RF armor; only one box for 2x radios, 4mm instead of 5mm wire etc..)

    I simply cant believe you suggested a telomast; the only thing i agree with you on is the wiring but its still in a sealed box; and the switch mode doesn't come with a cover; could hot glue be used?

    Agree about lighting protection; the experience we have had with even ubnt tough-cable hasn't stopped towers from being hit

    Agree with the wires they aren't under load; which is why im not getting in a debate about grip position

    4w max only on certain channels:
    http://freenet-antennas.com/PHP-Nuke/modules.php?name=News&file=article&sid=33 you cant use the indoor channels outside (although we have seen plenty of large Wisp's and private companies completely ignoring this)

    and the fact this is a hobbie; and not some telco giant's lastest build
     
  19. Blinky

    Blinky Member

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    That sounds a bit like schedule 80 pole. I use that on wind turbines. :)

    On my monpole ATM I'm leaning towards coming out of the ground in 150mm with welded on flange plates at the mid point then switching to a smaller dia for the top section.

    I've got it a bit easier than you, as my masts can't fall on anything but the bush and maybe a wallaby, I wouldn't be so keen to be inventive in suburbia.

    Yes, I think we all must have that image in our image folders. ;)
    http://i.imgur.com/ODEYI6u.png

    Just quietly, I'd still tuck those guy tails back through for the locking like I linked to in that image :thumbup:
     
  20. Aetherone

    Aetherone Member

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    That all depends on how annoying your supercilious attitude will find it when I don't.

    That was the several meters of coax that was removed in the later iterations of the project?

    Although, the indoor cat5 versus outdoor STP is something I agree with, it all comes down to budget and user preference for how well they want their hobby kit to work.

    I presume you mean self-sealing silicone tape and not the 'leccy variety. For a guy who's so anal about everything, not specifying the precise "tape" down to the product code is a serious oversight.
     

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