Triax110cm dish with 4 x LNBs, some help setting up please....

[drh]

Good evening everyone.

I live in the south of the UK and have set up a new Triax 110cm dish with a single LNB focused nicely on Hotbird 13E.
The dish is angled at the correct 31Deg on the inclination scale as shown in the Triax instructions for Hotbird 13E, and the signal is excellent as you would expect.
Having set up the dish correctly, I want to replace the single LNB with the Triax 4 x way multiple LNB bracket for this dish.
Unfortunately, the design of the plastic mount fouls the clip that holds the LNB and prevents any of the 4 x LNBs from being mounted at the prime focus of the dish as with a single LNB.
I could (just about) carve a chunk out of the clip that holds the LNB and another bit out of the plastic bracket to allow the LNB to be at the prime focus of the dish, but much of the mechanical strength would be lost.

Can anyone please suggest the preferred method of setting up this combination of dish and 4 x LNB bracket?
I would like to receive 19E, 13E, and 9E plus perhaps one other satellite.
I am using the bullet LNBs so the limitation is when adjacent clips foul each other rather than the LNBs themselves.

Any thought would be much appreciated, please.
Many thanks in advance.

Dennis.

[Capt Scarlet]

one of these will be ideal 4u m8

[gadstamut]

I've always wondered how you would go about aligning the triax dishes with one of those rigs. I'm kinda thinking you point it at a sat you dont want and use the reflection rule to setup the four you do want.

[drh]

one of these will be ideal 4u m8

That is the bracket I have.
As you can see and like I said, the mounting bracket fouls the LNB clip and you cannot put an LNB at the prime focus of the dish.

[drh]

The instructions at first seem good, but when you read them properly, they are limited.
There is only one table for the 110cm dish for the UK and this implies you want LNB1 at 13e, LNB2 at 19e, no LNB3 and LNB4 at 28e.
There is no other useful information in the instructions.

I don't need 28e and I want to be able to use a fourth LNB.
There is a 20 degree angle available, so it should work between 0-20e, but not if set up as shown in those instructions.
I would like to try LNB1 at 1w, LNB2 at 9e, LNB3 at 13e and LNB4 at 19e.

Any thoughts would be much appreciated. I already have this bracket, does anyone else have this wretched thing?

Thanks.
Dennis.

[mdt]

try fixing the dish on 9east without the multi-bar on the dish then ajust the lnb,s for the best possible signal on each lnb. i fitted one once on a TD88 and took no notice of the instructions and just altered to the best signal but i was using a horizon meter to aid me,regards mdt

[echelon]

I put the lnb as close to the centre point as possible for hotbird and it works fine , it doesnt have to be dead centre and you can actually align it anywhere on the rack you like , bearing in mind this will mean you get some sats and not others , so just use it near the centre , either on one side of the other , then try 19e on a different lnb holder, and any others you require

[Roadrunner]

Thats what I thought too.. In my setup (as per our conversation with you Echelon few months ago) I focus on 19E (the holder is on the left of the arm about 2" to the left (looking at the dish) rather than the 13E as wanted to cover some more westernly sats as well In my setup I get 28, 19, 13, 9, on the triax td78 dish + 16 E 7E, 1W on the other + 39E on the sly dish, giving me 8 sats altogether over the 3 dishes with a 8x1 switch..Not ideal I know but it works. I would strongly suggest OP plays with his setup as there is no two same setups , what works for us may not work for him , so there is some thinkering needed as to how best use the gear available. With his setup I would have thought setting the 9E lnb closest to the left hand side of the arm would be best as it would allow
to fit in the 1W to the right (which is 10 degrees off) at worst turning the holder over so the lnb is actually hanging over the end of the bracket) and 13 and 19 on the left (those 2 should be easy as they are close)

[drh]

Thanks everyone.
I will leave the dish fixed at 13e as echelon suggests, then swap the single NB for the multiarm with just one LNB in a holder for 13e.
That sounds like a good starting point.
I'm usually OK with setting things up and had a motorised NEC2022 from 1987, then a Discus Ellipse after that, then Humax and Technomate 6800HD.
I've not use one of these arms before and the options in the instructions are not clear for the UK.

I'm over fussy sometimes, but will say the Triax kit is good quality and all the bits fit together with no problems.
My only criticism is the lack of plain flat washers in the kit which I find are necessary when progressively aligning and tightening the various parts.
The extra cost would be minimal for Triax to supply some.

I've post again here once I've got my 8-way switch and bullet nosed LNBs.

Thanks again everyone.
Dennis.

[gbmitie]

what you are attempting is tricky and patience. the big snag is getting the triax lnb aligned correctly, as the sats are at different positions in the sky the lnb bracket has to be adjusted to acccount for that. 28east is the highest so bracket will be at its highest to the left as you look from the front BUT even then the bracket may be wrong so the trick is to turn bracket upside down. You dont need an lnb dead centre as the idea is to receive more than one sat so all sats will not be received at 100%.

To assist you here are 2 images of your dish been used to get 4.8e, 13e, 16e, 19.2e, 23.5e and 28.2e.

One of the images, ie no 3 is when you get expert.:applause-003:

[drh]

@gbmitie,
Thanks for those pictures, but how did you manage to mount the (centre) bullet-node LNB at the focal pont of the dish with the plastic mount for the bracket in the way? If I can do this, then I can set up all the LNBs without moving the dish.
Could you please post another picture (or rough sketch) of how you did that?

The alloy bracket has two channels cut in the casting.
The central mounting hole is drilled though one of these channels and is therefore not along the centre line of the bracket.
The instructions shows the hole to be in the uppermost channel when attached to the plastic mount.
It can be mounted upside down which will raise the bracket (and LNBs) by about 1cm from the centre line of the dish.
Your bracket appears to be mounted upside down when compared to the instruction leaflet.
Your bracket has much more rotational swing than mine for this reason.
(These are just my observations, and not intended as criticism of course).

I'd really like to mount the central LNB as you have.... it would be great if you could show this so I can copy it (assuming you don't mind).


Many thanks.
Dennis.

[gbmitie]

yes bracket has to be upside down, the way to mount the middle lnb is quite hard to do.... not really its just wedged in place no drilling etc. This is not my work but I remembered when it was being done as I had the triax bracket at the same time. Because of work I gave up. I got a motorised set up. And I have 3 dishes. I was really keen to do it as I had a dual set up from years ago. I even got the bullet nosed lnb's. I will search back for the thread and give you a link, its a massive thread as quite a few were attempting the same idea. I think the one I posted is on a Triax 88cm dish! And if you look very closely you may even have to re-drill the bracket. I'll get the thread as the evening wears on and post the link.

[drh]

@gbmitie. Thanks again for your help. I've got a couple of those brackets as I thought I might need some spares anyway; a tenner a kit on the usual ******* site.
I was going to cut and mount one of the LNB holders on top of the bracket, but at the last minute, realised the new hole for that would go through where the clamping screw passes so I looked at the clamps that use a nut and bolt arrangement that is opposite the bit where it is fixed to the dish, but these are either cheap and nasty with no 'meat' to them or too big if they are better quality.

I think I may start with a wide jubilee clip and make one myself from this.
After all, isn't this is half the fun of playing about with this stuff?

Thanks for helping. I'm not in any rush; I just want to get it right.

[drh]

Ok, I've spent longer than I expected on this as there were a few problems.
I hope the following may be useful to others.

The Triax dish and 4 x LNB bracket arrangement is not a particularly good design.
The hollow arm that carries the LNB is supposed to carry the cable inside it. Don't bother as there are lots of sharp edges to cut the insulation and I couldn't pass two lengths of twin cable through it as there wasn't enough room.
I fastened my cables to the underside of the arm using cable ties.
The arm itself is too low and I had to adjust it (bend it carefully) to make the focus of the dish at the point where the LNB lies (one LNB in the normal place). Raising the LNB by about 2cm made the focus at the correct position.

Now on to the 4 x LNB bracket.
There is not enough adjustment vertical adjustment without fouling the plastic mounting bracket and this was probably the reason for gbmitie mounting his bracket upside down.
I drilled a second hole in the aluminium channel below the manufacturer's hole and then either hole could be used without having to remove the LNBs and turn the bracket upside down.
It is not possible to mount a LNB in the centre of the bracket due to fouling of the bracket by the LNB clamp.
A cheap solution was to purchase a pack of 25mm conduit saddles (B & Q plastic) and mount one of these in the centre on top of the aluminium bracket.
Extra conduit saddle bases were use to raise the LNB to the same height as those using a clamp for mounting.
A piece of 2mm silicone rubber sheet was wrapped around the 23mm LNB shank to fit the 25mm conduit saddle.
So stage 1 was to mount a LNB in the centre of the 4 x LNB bracket and align the dish to Hotbird at 13e; this was easily achieved.

Stage 2 was to fit a second LNB to the left (west of) the prime focus LNB and move the second LNB around for best signal on Astra 19e.
The 23mm to 40mm adaptor was a poor fit inside the LNB clamp due to cast ridges in the latter that are supposed to stop the LNB turning.
Once the plastic ridges were cut off with a sharp knife, the LNB could be securely clamped with no daylight visible around it.
Fine tuning was achieved by raising the westerly end of the LNB bracket and rotating both LNBs for the storngest signal on the meter.

I've attached some pictures of the setup with just hotbord 13e and Astra 19e LNBs fitted.

The original dish + LNB bracket design is flawed and needed several modifications to make it acceptble for me (but perhaps that's just me).
I know there's no absolute necessity to fit one LNB at the centre point of the dish, but I wanted a proper reference point set up correctly i.e. 13e.

Do NOT try to pass the cables through the Triax LNB arm; there are lots of sharp edges and the outer sheath odf the cable will be ripped as you pull it through.
It's a shame really as the dish itself is nicely made, but the arm is crudely made and of poor finish.

Hope that helps someone; it took me a couple of afternoons to get it right whereas I had expected to spend just a couple of hours. P1020382.JPGP1020383.jpgP1020384.JPG