Dish line of sight

[Zed]

Hi Guys,

I realise this is a difficult question to get a answer to, but I thought I'd try and see if anyone can advise me. I've attached pictures of the back of my terraced house. You'll see a dish pointed at 28.2e, and notice the neighbour has an extension built that extends a few metres beyond my wall (where im installing the dish). I'm wondering how this might limit my reception of some satellites. I'm thinking it will prevent me from getting most of the western sats? Some of you have installed lots of setups, so maybe you have a better feel for these things than me Im installing the dish to the right of the brown framed window on the left.

The dish im installing is a Triax 110, with Dark Motor.

Thanks for any replies.

 

[Mickha]

West is to the left of the dish, as you're facing it, but there is still a way of getting all the satellites you require using some T & K brackets and a sturdy pole to mount the dish just above your gutter.
Try the sites dishpointer software:
http://www.satellites.co.uk/forums/dishpointer.php
and check out pictures of members dish installations:
Picture of Members' Setups and general satellite installations

 

[Vipersan]

The extension wont affect you at all really ...
As you still will have clear line of sight for most of the sats East of (ie to the right of )your mini dish as you face it
The sats to the west would be a problem as your own house is in the way ...ie the wall to the left of the mini dish ..
You'd have to get your TD110 ...higher up so that it cruised above the gutter line ...
But a TD110 at this height would be fairly exposed ..
rgds
VS

 

[Zed]

Thanks for the links. Very helpful. Judging from Dishpointer, the extension would only be a problem from about 120e and above, which I wouldn't and couldn't receive anyway. My problem is going to be the western satellites it seems, due to the wall. If you look at the pics attached, it will be difficult for me even to face the satellite at 5w, which is my 'true south' sat. So it looks like I need to position the sat on a pole above the guttering to get any western sats. Is that correct?

Thanks

 

[Vipersan]

Yes indeed Zed ..
you would have to position the dish/motor assembly above the gutter line ..as has already been suggested ...
The problem is that the Triax TD110 ..which is what I'm assuming you are fitting ..is a very heavy steel dish ..
Its pushing the limits of your motor as it is ..
..and to raise the whole thing above the gutter line is exposing the heavy dish to maximum wind loading ..
Make sure you have at least a one pair of secure ..good quality..T & K brackets holding your mount pole ..
If it were me ..I'd overkill and fit an extra K bracket for good measure..
Also use a quality pole ..
Nice thick steel ...not aluminium..
rgds
VS

 

[Zed]

Not sure if my last post was posted, so if this results in a double post, i apologise.

Thanks for the advice Viper. I'm a bit gutted by this lol. I really should have researched all this before ordering the setup. To be honest I don't think i'll bother going above the guttering as I really don't want to work that high, and dont want to draw attention to the dish, as Im not applying for planning permission. I'll just resell the setup (at a loss no doubt) and buy an 80cm with multi-lnb. I only really wanted 28.2, 19.2 and 13e. I just fancied the thought of having a big dish setup and a motor again. Anyway, thanks for the advice.

 

[Analoguesat]

Why sell the dish? A nice sturdy pole and some T&K brackets all set up below gutter level will give you those birds no trouble with some offset lnb brackets.

 

[Mickha]

You don't need planning permission for dishes 1 Metre, or less, and the Triax isn't that much bigger, I doubt if the council will come round to measure it. I've had a 1.2M up, for many years, without any complaints.

 

[Zed]

Thanks again for the advice. I have a couple of further questions, if you don't mind.

I've checked on eBay and I can get a 36" heavy duty steel T&K bracket. However I don't think the pole comes with it. What kind of a pole would I need and does anyone know the best place to get one?

Also, can someone tell me what an offset lnb is and how it functions? I've checked the forum and google for info and while I've seen people talking about them, I can't find info on how they work and how one would help my situation.

The help is much appreciated.

 

[PaulR]

It's not the LNB that's offset - it's the dish.

There are two basic types of dish: the first is circular with the LNB in the centre pointing towards the focal point - this is called a prime focus dish. The second is an off-set dish and on this type the LNB position has slid downwards and then the LNB points upwards towards the centre of the dish. These dishes are usually oval and longest vertically, if you squint up at the dish as if you were the LNB the dish then contracts visually and looks like a circle. The $ly minidish is a special case with its horizontal oval shape; it's still an off-set dish but has a special LNB to go with the shape.

There's no theoretical reason that an off-set dish and prime focus dish should have different LNBs but they have developed differently and have different focal lengths (how deep the dish depression is essentially) and so the horn part of the LNB is shaped differently for the different focal length.

You CAN use use one type of LNB on the other type of dish (if you can get it to fit!) but the wrong shaped horn means that you'll either get not enough signal collected or some noise from the outside of the dish area to degrade your signal. Only in an absolute emergency!

Most off-set LNBs come with the horn built on as the focal length is pretty much the same for all but prime focus dishes have various focal lengths and as a result the horn is purchased separately from the LNB and then adjusted to suit.

 

[Zed]

Thanks for that Paul

I have another question (surprise, surprise!). I thought I'd ask it here instead of making a new thread. It's not terribly urgent, just a curiousity.

I've been looking at Disqec switches on eBay. I'm going to go with a multi-lnb (3) setup. I've noticed some switches have weather-proof housing, and some dont. Do I really need the weather-proof housing? It would be handier to buy a basic metal switch and cable tie it to the dish arm rather than have to drill more holes in the wall to secure a housing.

Thanks again for all the help and sorry for bombarding you guys with questions!

 

[Analoguesat]

If a switch is supplied with a cover use it. It keeps the rain out of the ends of the cables and saves you having to get amalgamating tape in the fiddly spaces between the ports.

Theres no reason you cant just zip tie it to the vertical part of the lnb arm or the mounting pole as long as its secure.

 

[rolfw]

Most if not all of the housings can be cable tied to the pole, so there isn't any dilemma.

 

[Magnu420]

mount the dish to the extension (ask permission of the owner) and use a length a scaffold pole,ask a engineering firm,or scaffolders,scrapyards etc

 

[Chris76]

Hi Zed

I am willing to offer you a hand with the install mate if you need a hand no problem..If not good luck and keep us posted

Chris

Thanks for that Paul

I have another question (surprise, surprise!). I thought I'd ask it here instead of making a new thread. It's not terribly urgent, just a curiousity.

I've been looking at Disqec switches on eBay. I'm going to go with a multi-lnb (3) setup. I've noticed some switches have weather-proof housing, and some dont. Do I really need the weather-proof housing? It would be handier to buy a basic metal switch and cable tie it to the dish arm rather than have to drill more holes in the wall to secure a housing.

Thanks again for all the help and sorry for bombarding you guys with questions!

 

[Zed]

Thanks a lot Chris, I managed to get it setup ok. Do you happen to know anywhere in Belfast that sell Triax dishes? Particularly the TD88. Cheers

 

[Chris76]

Vanjak rigging Zed. We don't really have a great choice of suppliers over here.

 

[Terryl]

I'm a bit late to comment on the pole, but I use 2" ridged electrical conduit and have the custom braces made at a local welding shop.

The 2" rigid conduit needs a hydraulic bender to even put a dent in it, at the top I use a 2" to 1 1/2" bell reducer (plumbing part) for about a 5 foot mast for the motor and antenna to mount to, a standard pipe cap will keep the weather and birds/bugs out.

At the base a pipe flange is used to connect to the concrete using red heads or if your pouring the mud your self 4 "L" bolts about 8" long work nice to secure it.

In your instal two wall mounts would be enough to secure the mast, raising it in one piece would be a team effort.

I have attached a photo of one of these setups, it has stood up to 60 MPH winds and some heavy snow, the dish is a 1 meter with a SG2100 motor, a Invacom LNB is at the end.

The second photo shows the wall bracket and bell reducer.