How to check an LNB

Seamie_irl

Hi all,

Newbie here but not quite newbie to installing a satellite dish!

I'm installing a satellite dish for the fourth time. The joys of moving house! Anyhow, I purchased a 90cm offset dish (80cm wide, parabolic), quad LNB (local supplier) and set it up. Used compass, the guage on the dish mount, dishpointer.com but all I'm getting is a signal strength and zero quality. I've adjusted the four main settings (azimuth, elevation, LNB skew & LNB distance (from dish)) incrementally keeping three settings fixed and changing one. There isn't the slightest change in signal quality.

My dish is at first-floor level. It's about 2 metres from a shed which it is facing but the line of sight between the bottom of the dish and the neighbours roof is above the highest point of the shed. My dish is about 1 metre higher than my neighbours and pointed in at least a similar direction. His dish is the standard sized smaller dish.

I've used a Revez SP50 Satellite 'finder' which I'm not impressed with.

I've been at this for 10 days (when I can find the time in the evening weather permitting etc.)

Having failed with all the above my next port-of-call was that the LNB was faulty. The receiver I have is a Combobox (Edision) and it's working fine for Terrestrial (aerial is mounted directly above the satellite dish and pointing in almost the same direction). I purchased a second LNB from an online retailer (my experience buying this stuff locally was less than positive) with the same results.

I have a second receiver which is satellite only but haven't used in 5+ years and getting the same result.

So, I'm back to thinking the LNB is faulty. The first LNB was Visiblewave VK4L. The second LNB is RT. What are the chances of buying two new LNBs from different suppliers and both being faulty?

Is there anything I've omitted or overlooked? Is there any way of checking if an LNB is working?

I'd contact a local installer but that he'd probably be p***ed cleaning up my mess.

Thanks for reading this far. All help welcome.

swoofer

You need to say what the dish is mounted on, is it a pole etc. And to work properly it has to be 100% vertical and the dish has to be square to the mount.

What skew did you use? ie the number of degrees and either left or right from front, sky is you turn lnb to left as you look from front.

Elevation on dish, sky for ireland is almost vertical, aout 21/22?

Have you a satellite listing in the edison combo, say the model, ? If you have select BBC1 have dish elevation and skew as per dishpointer, don't worry too much about focal length yet. then have dish pointing same as neighbour, move slowly as digital signal is slow to reach box, have volume loud and listen.

a few pics would be useful and 10 days is dedication, where are you roughly?

Both those lnb's look okay and the RT one if its a black ultra is one of the best. The only snag could be if the word quattro appears on both lnb packaging.

You will only have the azimuth set correct when you get a picture

I'll do you a pick of an RT octo and show you skew and how far from dish in a little while. do pics if you can, you dont need an installer.

Id say something in way in line of sight or dish mount is crooked.

Seamie_irl

Thanks SWoofer for the quick reply.

I'm in Galway City.

The dish is on a pole which is true (spirit level checked).

The LNBs are Quad (not Quattro). The current one is RT Inverto Black Ultra 40mm Quad LNB.

The elevation is set at just over 20deg (as in 20-21 deg). However, I've checked it from about 10 deg to 30.

It looks like, as a newbie here, I can't post pics. At least I can't see the 'attach' icon.

I've tried the skew at 0 deg to start with. However, it's currently set at about 22 degrees negative (clockwise rotation - about 1-2 O'Clock facing the dish)

The focal length is set as 'centre'.

Receiver: Edision Piccollino 3-in-one (in use) / Xoro as a backup

I'll not get out on the step-ladder in the next 36 hours at least what with the storm warning.

Ger Roe

Keep at it. Getting correct dish setup is like water divining - a black art. You don't believe it can be done, until you get it working. I was faffing about for months before I got the knack. There were often times when I thought that something was faulty, but now I can do it quite easily.

Everything has to be spot on. Be sure you have line of sight - no obstruction. Tune to a known strong signal on the box - eg BBC1. Get the LNB skew right for a start then look at dish elevation and then sloooowly swing about at that point.

You are dealing with millimeter accuracy on each of the dish parameters so you need to be very close to where you should be, before you try adjusting any one of them.

Patience and good luck.

ChuckieEgg

Just a thought but is there power going to the LNB from the receiver?

swoofer

Tthis is your fourth time so you know the bits required. Why did you go for such a big dish? I'm in clare and use a triax 68cm.

The skew for galway is -16.8, -17.1 in Clare!!

After listening to the storm I would check the connections, could be a bit of braid touching the inner core at both ends!! The only way to test lnb is with a signal. And check line of sight again!!

Seamie_irl

Thanks ChuckieEgg,

There is power going to the LNB because I can power the (useless) Revez Satellite Finder from the receiver side

Seamie_irl

Thanks SWoofer,
I went for a big dish because I'm hoping to add offset LNB's at a later stage to increase the channels (adding a DiSEQ). However, my experiences to date have paled that somewhat.
The skew value seems to vary from 16-24 degrees depending on the site you visit. I'm just thinking again .... 16 degrees would be half-way between 12 and 1... but either way, even if the LNB was at 12, I should still get a signal however crappy. It's just giving me zero and that's the disconcerting bit. Having done it previously with smaller dishes I found the azimuth was fairly tolerant.

I'll check the coax to the LNB again. The only SNAFU I made was under-estimating the length of coax required. It's about a meter short so I've a length spliced and joined with F-connectors and a male-male join. The SNAFU had an upside initially in that I could switch in the Satellite Finder.

I'll have another go though it may be tomorrow before I can try.

Thank you all for your input. It's incredibly frustrating but great to have the support.

Seamie_irl

Ignore the slung wires. I tidy all when everything is where it should be! :-)

swoofer

aha what do they say, every picture tells a story!! Remove aerial move dish up and bingo you get a signal. Then when OK you can fix aerial to pole using a special bracket that allows you to add a pole.

Look here, I got the clamp but if you look to the side you will see other bits as well, like pole coupler.

https://www.freetv.ie/shelley-8-nut-pole-clamp/

Simples

Elvis Hammond

swoofer wrote: »

aha what do they say, every picture tells a story!! Remove aerial move dish up and bingo you get a signal.

That shed isn't in the dish LOS, if that's what you're suggesting.

Seamie_irl

Hi Elvis,

No it isn't as I've checked that. There's another house at the back of us and the LOS between the dish and the roof top is above the shed.

In all my too'ing and fro'ing with the dish, I think I've also knocked the aerial out of line as TG4 and VM1 are unwatchable. Anyhow, that's another day's work. LOL. FML!!

S

swoofer

Well the logic in raising the dish is to definitely discount LOS problems, you have done that, at the moment there is either no signal or something blocking it. Any overhead wires? Can you move receiver to continuous lead? Did you have a close look at connections?

And can the dish move left and right to definitely get 28east, have you that smartphone app?

I'm in clare so if you pass through ennis I'll check that LNB and box!!

It has me intrigued.

Ger Roe

Certainly move the aerial from overhead. The angle of incidence (degree at which the signal hits the dish) is much higher than most people imagine - coming in more vertically than you would think. There is certainly a possibility that the antenna is being hit, before the signal reaches the focal point of the dish.

Usually the antenna is mounted lower than the dish so as to not obstruct the focusing process. Or else mount it separately to the dish altogether.

Elvis Hammond

I'd doubt the aerial is doing any noticeable harm, but I'd be happy to be proved wrong.

It probably needs to be mounted somewhere else higher up to get a decent signal anyway.

Seamie_irl

Hi all,

I got it sorted!!

Rather than picking at it I decided to re-do from start. I re-made all the connections both inside and out. I also took a smaller TV into the kitchen and slung a long coax out the window. BINGO! What infuriates me is that so called Satellite Finder sung like a bird once I'd found the satellite using the signal meter on the Receiver. It's seriously a waste of money.

Once that was done, I was able to confirm the signal in the sitting room and finally put things back together so now the TV is on the wall with all of the necessary equipment and connections hiding neatly behind it .

What was the cause? I've no idea. My money is on the two F-sockets in the sitting room but I can't be certain. Previously when I'd installed satellite dishes I'd always been able to connect them to a TV that I could see while up on a ladder with the satellite dish.

I've the cables to tidy on the dish yet but I'll get to that once the weather improves a bit.

Lessons? Don't attempt aligning a satellite dish if you can't connect it directly to a receiver (and of course a TV) even as a temporary measure. DON'T buy the Revez SP50 Satellite Finder! It's a bloody waste of money.

Thanks to everyone who gave advice and suggestions. I really appreciate the support.

S