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| Thread ID: 50069 | 2004-10-09 11:24:00 | Antennas and Leakage | Growly (6) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 279591 | 2004-10-13 11:01:00 | Get a couple of quotes one from a builder and one from a TV areial person, go with the most expensive. As you dont own the house just pass the bill on to the owner. |
Rob99 (151) | ||
| 279592 | 2004-10-13 11:36:00 | Hi Growly Get yourself a heavy duty hocky stick mast from somewhere like Matchmaster (Strongline) 31 Bridge St, Lower Hutt 569 4916 or there's one in Motuhara Rd in Plimmerton 233 8194 (can you pinch the redundant TV one), they'll have all the correct fittings and bits and bobs. Hang it off the house (make sure you have found a stud or dwang to attach it to) and brace with tubular metal stays off the fascia or if thats not high enough, mount it on the gable end fascia (the pointy one) and brace off the roof with stays. If you need to put the sealant on from inside the roof cavity your holes are way too deep or you've missed the solid stuff. Try not to use silicon or RTV where it is exposed to sunlight and the weather, use neoprene washers instead but do squirt some goo into the fixing holes and under brackets/mounts. The drip loop is just a few 100mm of extra cable that sags below the entry point of the cable into the house. If you pop it up through the soffit lining (the eaves ceiling, if you like) and on into the roof cavity that will suffice as a loop, gives you less to flap around in the breeze as well. Um! and Growly be carefull, got a scaffold or a harness? ;) Cheers Murray P |
Murray P (44) | ||
| 279593 | 2004-10-13 20:21:00 | > My dad himself must be credited at this point, as he > believes that in no way should I put it in the roof . > This is probably because, although he hasn't told me, > there is a large amount of reflective metal in that > attic - none of which he will be willing for me to > cut - so although feasible, as these are powerful > antennae and it's only wood . . . the man will > have none of it :'( LOL :^O Must be where he hides his stash, no wonder he doesn't want you in there . The "reflective metal" won't matter squat because it will be outside the bore-sight of the dish . > I take the cable and do some sort of loop (not quite > sure where or how) so that the water drips off before > going into the house . In doing so, I increase the > signal loss (great . ) . No, it will have no effect on signal strength unles you kink or crush the cable . > I keep the cables dry, presumable with alot of electrical tape, or self- something tape . No, you don't need to tape the cable . Only joints or connections need taping to exclude water, but this install should have only one exterior connection and that should be inside an enclosure at the dish end anyway . > I align it using diagrams, compass bearings and depression angles, > which I figure out using some sort of tool (maybe one of those you > point up at the sun and click, and then it tell you the angle? Again no, you only need to do that sort of thing (minus the sun-gazing) if you are working blind inside the attic . Otherwise provided you can see the other dish you use your eyes and a bit of trial & error . I'd go back to the attic idea, there is less chance of you stuffing up the roof or the exterior of the house . Cheers Billy 8-{) You can always drill a 3mm hole to the outside and look through that to help with dish alignment, a squirt of silicon sealant closes it off afterwards and it would be invisible from the ground . :D When putting TV aerials inside lofts or attics (pottery tiles only) I used to pop-up a tile and check direction visually . |
Billy T (70) | ||
| 279594 | 2004-10-13 21:00:00 | Growly, how much coax cable do you intend to use? Anything more than a metre and you going to experience serious signal loss. You may need to consider mounting your AP close to the antenna to minimize the amount of cable required. The AP could them be connected to the rest of the network via cat5e and you could use PoE to power the AP. | Pete O'Neil (250) | ||
| 279595 | 2004-10-14 04:28:00 | That's a nice antenna Growly, I took a look at your link and found this quote: Computech South Ltd has two of these products running as a network bridge from South Invercargill out to Lornevale which is 8 . 6KM . You will have no trouble establishing a link over the short distance shown in your photos, even from inside the attic . Re coax though, you haven't said what you will be using but unless it is absolute rubbish I can't agree with Pete's view that more than a metre will cause serious signal loss . If you have the right type for the job then 5-10 metres won't cause much grief at all . Just make sure you buy good low loss cable rated for 2 . 4 gHz use . Cheers Billy 8-{) |
Billy T (70) | ||
| 279596 | 2004-10-14 06:37:00 | Excellent! Thanks so much everyone, hehehehe . . . . Right so now that my views are corrected - my options are a) mount on existing but slightly out of line of site TV antenna mast b) mount in secret attic c) get some chunky masts and secure tightly to roof, with aid of trampoline on ground and facia mounts . Oh, and d) read a book on aerial theory . As far as cable goes, I have some really expensive, ~$12 a metre type stuff lined up . Unfortunately, it may take a few metres before it gets to the er access point (which is infact a computer) . Hmmmmmmm . . . . . Oh and one last (well it's the last one untill I realise I have no idea what I'm doing and come crawling back for guidance) point . . . Will a 13dBm transmitter in a Wireless NIC be powerful enough? Or do I need a booster? |
Growly (6) | ||
| 279597 | 2004-10-14 07:06:00 | Have a read of this ( . nzwireless . org/posts59-highlightlmr400 . html" target="_blank">www . nzwireless . org) granted it might not be serious signal loss but with a 5m cable you loss around 2 . 5-3dBi, also taking into account that LMR400 is around $7-8 a meter the costs start to build up . In my opinion you'd need around 5-10m of cable depending on the location of the antenna in relation to the computer room . Now using the above figures you can expect to loss 2 . 5-5dBi and expect to pay $35-70 for the cable . Luckily Growly has one of the most powerful directional antenna readily avaliable in NZ, and is only transmitting over a relativly small distance . Now several people claiming to be antenna experts belive that the roof wont have any effect on the signal strength, im not a wifi expect but feel that the roof really should be taken into consideration . You seem to be going about this in a very expensive way, if you were able to mount the antenna outside and mounted the AP as close as possible to the antenna you could have easily gotten away with the cheaper 19dBi parabolic grid antenna . You would have also only needed a small length of LMR400 again reducing costs . Seeing as you are only tranmitting over a small distance you could have used a omni-directional antenna, it would have had the range and would allow for others to easily join your network (create a community wifi network) . Your friend could have used a cheap cantenna or home made bi-quad to keep cost down . |
Pete O'Neil (250) | ||
| 279598 | 2004-10-14 07:47:00 | Thanks very much Pete, unfortunately I can't change my aerial now... Nevertheless, the fact that it's so big just makes me feel like more of a man. Believe it or not I actually originally intended to use a Cantenna - I even found the right can, had the holes marked, scrounged up money and bough a type N connector - all to realise I had no screws and no 12 gauge unshielded copper cable. Then the antenna I got went on special (down 25%) and I just went snap and bought it (had savings). Now I'm deadset on mounting it and pointing it out there, and I will save if I must and get good cable to do so. Understandably it is a powerful antenna, and there will be a slight effect on the signal through the roof, but I'm not experienced enough to make a judgement. Anymore ideas are absolutely welcome. Infact I may start polishing shoes for all those who helped. Having said all that, a big dirty grid antenna on the side of the house is extremely manly. (Well, more nerdy...) |
Growly (6) | ||
| 279599 | 2004-10-14 07:54:00 | > Now several people claiming to be antenna experts > belive that the roof wont have any effect on the > signal strength, im not a wifi expect but feel that > the roof really should be taken into consideration . Hi Pete I would not advocate trying to establish a link through a metal roof . From the photos Growly has supplied it appears that he has a clear shot through the end gable . You had better check that Growly, as the guy on site you are the only one who really knows what lies between your antenna and its target . Cladding should be no problem so long as no metal or foil is involved, with reasonable power input and that antenna gain you should be able to establish a reliable link through trees or even an wooden building . I note from its specs that it is recommended for WiFi links inside buildings . Cheers Billy 8-{) |
Billy T (70) | ||
| 279600 | 2004-10-14 08:26:00 | Growly . . . you are getting a lot very good technical advice and I am sure that you will get the link to work . My last on this is simple . You don't have to resolve this problem before you do anything . You are the man on the ground . Have a go . You own everything so try what seems feasible - and simple . Put the dish in the attic if it seems that it may possibly work and see what happens . . All it is going cost you is a little effort and time . If it doesn't work so what the hell . You have learned something . Now move on to the next step - whatever you want it to be . As long as each attempt doesn't involve a commitment you are not willing to make, either financial or structural, try it . There is nothing like a little experimenation to broaden the mind . Once upon a time that is what ham radio was all about . When you have finallly found the spot where it will work, come back to this thread to get all the bells and whistles that will make it an A1 installation which may even earn some parental brownie points . |
Raymondo (5284) | ||
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