More help on setting up my mobile sat dish

[jules456]

Me again. I’ve been getting pretty good results with my mobile dish over the last few months. Hoping to minimise my tuning time further and I’ve ordered a digital angle finder. Where abouts do I put it on the LNB arm to measure the right angle?

Hope I’ve put enough info here. Thanks.



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[gordon_s1942]

Being Mobile, I am guessing your using a Ku Band dish?
On a Ku band dish, you normally set the angle using those marking where it attaches to the mast.
I have go a 1.8M solid fiberglass C/Ku band dish and it has a ledge on the underside to attach an angle finder.
I will defer to the others on this but not all Ku band dishes use the same angle, length type of LNB arm so all I can suggest is to make a mark on the arm (permanent marker) and put the angle finder there and record the details to use them the next time your there.

When I was fiddling around with the solid dish, I used a protractor with a hole drilled where the lines all met, a piece of string with a small lead fishing weight and using paper clamps, attached it to the place provided.
To make it more interesting, the dish was OffSet too, not a centre feed as most that size tend to be.
Rough as guts but it worked.

[mtv]

Angle finders are only really useful when used on prime focus dishes, where the LNB points directly at the centre of the dish from 90 degrees in front of it.

An angle finder normally is attached to a surface that indicates zero when the dish is pointed at the horizon, but that only applies to prime focus dishes.

As mentioned, the dish mounting bracket on an offset dish should have elevation degrees markings on it.

Those markings indicate the true angle the dish is 'seeing' taking into account the offset amount.

I have seen some horrible-quality portable dishes that have an integrated triangular base that have a sliding telescopic section to adjust elevation with no markings.

The problem using an angle finder with offset dishes is exactly that... it's offset.

The amount of offset varies on the design of each model of dish.

The dish surface is at a different angle to the LNB, which is typically mounted lower than the dish centre and 'looks' slightly upward at the dish surface, hence the name 'offset'.

The dish physically aims at a lower angle that what the beam angle is.

There is nowhere on an offset dish to place an angle finder that will give you a direct adjustment angle reading.

Unless you know the dish offset angle, you will be pointing the dish incorrectly, usually way too high.

I've seen offset figures of between 18 - 25 degrees, but as I said, each model of offset dish varies.

If you have a dish with no elevation markings, I highly recommend you get one that does.... it will make alignment so much easier and quicker.

[gordon_s1942]

As your traveling around, have a look at the dishes installed by both Foxtel and Austar and and I have seen totally different types used both in towns and rural areas.
Round, rectangular, egg shape, some with pipe type LNB support arms , some with curved arms, others with L shaped ones.
Its my understanding that all of these dishes are supplied to the installer and they are prohibited from using any other which means the Service provider buys whatever is available at the time.

[lineland]

You will probably find a digital angle finder will slow you down.
What is your issue getting the dish aligned?
I use the WikiCamps App Satellite Finder and generally two minutes will pull me up, and usually faster than two minutes.
I know from experience the satellite will be about 4 degrees to the west of what my phone compass says.
What I do have on my satellite dish is wing nuts with fibre washers backed by flat washers so you have a smooth movement with a bit of friction so the dish can be easily locked in position when the satellite is found.
The type of dish mounting bracket makes a significant difference to ease of movement and operation to locate the satellite. Personally I would never have any other dish than with four locking screws with centre pivot. Lousy dishes are a problem, and those mongrel units that sit on the ground on a triangular frame are a disaster. I either use an arm on the back of my caravan, or a small quality tripod on my 4WD camper.

[gordon_s1942]

What I did to stop the dish (Ku Band) sliding down the mast while I was setting it was to use a large U clamp onto the mast and sat the bracket on it.
This way I could keep the bracket firm against the mast yet it let me turn it as I needed to.
At the time I was looking at other Satellites so this enabled be to do so on my own.

[lineland]

What I did to stop the dish (Ku Band) sliding down the mast while I was setting it was to use a large U clamp onto the mast and sat the bracket on it

Never seen a dish that didn't have a bit of metal protruding out on the top of the bracket to prevent the dish sliding down the pole.

[mtv]

Never seen a dish that didn't have a bit of metal protruding out on the top of the bracket to prevent the dish sliding down the pole.

We're getting a bit OT, but yes, they do exist.

A lot of earlier Hills Foxtel/Austar dishes used plastic U-bolt retaining clips for that purpose.

As you say, most these days have a small metal tab on the mounting bracket that sits over the lip of the pole.

[jules456]

Thanks all for the suggestions and comments. I’ve been out of phone Reception for a few days.

The dish is from access antennas and there is markings on the underneath of the dish. To be honest they are really vague and I’ve found them quite useless. My hit and miss scanning the horizon in the approx direction has seen better results.

The dish came with an angle finder which you put on the back of the dish but I left it at home! I was thinking that getting a small angle finder would help in the tricky set ups to try and eliminate one part of the set up to find. I’ve been using wiki camps which is good most of the time, but as said, it’s the 5-10% of the time when I might have a little bit of interference that I was trying to work around. I might just have to try the permanent marker trick and remember the difference in any offset.


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[lineland]

The dish is from access antennas and there is markings on the underneath of the dish. To be honest they are really vague and I’ve found them quite useless. My hit and miss scanning the horizon in the approx direction has seen better results.

Jules you will have substantially better success just scanning around. Those angle finders are useless as are the graduations on the bracket close to useless. The angle finder and the graduations on the bracket are only some good, provided your dish set-up is 100% level to a micro tenth of a degree. Forget all the gadgets - leave them at home. You will stuff around more with gadgets than just swinging the dish.
One of the most important things is to have an engraved LNB see they are sold out, but no doubt will be back shortly. Another issue if your LNB is a cheap and nasty unit, they don't have the sensitivity of quality LNB's. Another issue if the LNB has a serious knock can impair their sensitivity as an LNB is a precision device. In your case this won't be an issue, but travellers should change their LNB's every five years purely from being knocked around. I have helped hundreds travelling around Australia to set-up their satellite TV dishes..
On the WikiCamps App it gives you the LNB angle at the bottom of the screen. Make sure before you do anything else is to set the LNB angle.

What sort of dish do you have?
What sort of stand do you have for the dish?

[jules456]

Jules you will have substantially better success just scanning around. Those angle finders are useless as are the graduations on the bracket close to useless. The angle finder and the graduations on the bracket are only some good, provided your dish set-up is 100% level to a micro tenth of a degree. Forget all the gadgets - leave them at home. You will stuff around more with gadgets than just swinging the dish.
One of the most important things is to have an engraved LNB see they are sold out, but no doubt will be back shortly. Another issue if your LNB is a cheap and nasty unit, they don't have the sensitivity of quality LNB's. Another issue if the LNB has a serious knock can impair their sensitivity as an LNB is a precision device. In your case this won't be an issue, but travellers should change their LNB's every five years purely from being knocked around. I have helped hundreds travelling around Australia to set-up their satellite TV dishes..
On the WikiCamps App it gives you the LNB angle at the bottom of the screen. Make sure before you do anything else is to set the LNB angle.

What sort of dish do you have?
What sort of stand do you have for the dish?

The dish is from Access Antennas. It’s their “brand”. It’s 85cm. Not folding.

The stand is a folding tripod. It’s heavy duty and has the bubble on top to make sure it’s level.

The LNB I’m using is a Stong dual. I change it a few months back when I was considering running two cords.




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[gordon_s1942]

That Bubble on top isnt to get it 'Level' but to get the mast VERTICAL as thats THE most important first step in setting up the dish.
What you have looks to be the best and it sounds like your well versed in setting it up quickly.
To be honest with you, to have and do any better, you need to lay out a couple of $$GRAND$$ and go for one of those self tuning dishes........

Some time back we had friends who lived in Townsville and traveled between there and Melbourne exhibiting at Shows and he said he could have his dish unpacked and tuned in within 10 minutes of arriving at the Caravan parks he regularly used.
He started out using a signal meter but didnt bother after awhile.

[lineland]

The dish is from Access Antennas. It’s their “brand”. It’s 85cm. Not folding.

Hmmm people don't realise 85cm dishes are harder to to align than a 65cm. With VAST a 65cm dish is preferable anywhere in Australia. With Aurora you needed an 85cm dish in some locations, but not so with VAST.
Users think a larger dish is easier to use, but the opposite is true. You will meet travelers that will bet money larger dishes are better and easier to focus - sadly very wrong. Often in country areas you can find non-rusted good 65cm dishes at the rubbish tip shops for $5.00. These are ex pay TV and are good dishes.
If I can locate them, will post a picture on your FB of a dish bracket and how to set-up to make life easy.

The stand is a folding tripod. It’s heavy duty and has the bubble on top to make sure it’s level.

Well if you don't bother about angle finders etc. the tripod not been level is not at all important. The bubble on top of those tripods is not accurate enough to let you use your digital angle finder. However it will give you a starting point.

[jules456]

Hmmm people don't realise 85cm dishes are harder to to align than a 65cm. With VAST a 65cm dish is preferable anywhere in Australia. With Aurora you needed an 85cm dish in some locations, but not so with VAST.
Users think a larger dish is easier to use, but the opposite is true. You will meet travelers that will bet money larger dishes are better and easier to focus - sadly very wrong. Often in country areas you can find non-rusted good 65cm dishes at the rubbish tip shops for $5.00. These are ex pay TV and are good dishes..

Didn’t realise that at all! Thought we had to have the larger dish for WA. I’ve learnt a lot about all this over the last 6 months. It was so much easier at home when the dish was permanently set up by a professional!

Thanks for the FB post.


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[mtv]

With Aurora you needed an 85cm dish in some locations, but not so with VAST.

Generally speaking, VAST is more difficult to lock, compared to Aurora, as it uses DVB-S2 MPEG 4 when Aurora was only DVB-S MPEG2.

This is true of DBV-S2, regardless of service provider.

Aiming a dish is pretty much identical, but LNB skew adjustment is far more critical for DVB-S2 signals, regardless of dish size.

Speaking of which, yes, the larger the dish, the narrower the beamwidth, but a greater signal capture.

Stronger signal levels/quality = higher reception stability/reliability.

Like anything... the more you do it, the easier it becomes and a slightly larger dish usually poses any greater difficulty to align.

The dishes that can be difficult to align, are the pressed-metal dishes, typically those with a built-in flat triangular base.

Most are poorly made and warp/distort over time, creating a surface that loses it's parabolic reflecting properties.

**Important Tip** Most instruction manuals say to aim the dish accurately first, then adjust the LNB skew for maximum signal quality.

lineland recommends getting the lnb skew set (approx) correct first, a practice I fully concur with, because if LNB skew is significantly out, a decoder or meter (other than an analogue meter with no signal quality measure on a particular frequency) will not get sufficient lock to indicate when a dish is aligned correctly. Once you have a lock, fine adjustments to all settings are made to maximise levels.

As I mentioned, DVB-S2 signals (from any source, not just VAST) are more 'fussy' in this regard.

[lineland]

Didn’t realise that at all! Thought we had to have the larger dish for WA.
Thanks for the FB post.

Really don't know why they sell 85cm dishes to travellers. I have used a 65cm dish *ALL* around Australia including Cape York which is one of the poorest reception areas, and central WA only this year. An 85cm dish will hold signal better in a torrential downpour, but you don't get them often enough to be an issue. Other thing an 85cm dish on a tripod is a substantially bigger wind sail area, and takes a lot more anchoring down. 85cm dish is also a lot more painful to find somewhere to store the dish.

[gordon_s1942]

The bigger dish is a hangover from the Aurora days when it was claimed you needed the larger dish to receive the signal.
As time has gone on, VAST has been using a smaller dish but the one installed when VAST became available here is slightly bigger than my Austar/Foxtel dish.

I fiddled with an 80 cm dish thinking it was the golden rule that 'Bigger is Better' only to find out its was more difficult to use and I wondered at times was the dish distorted or the LNB wasnt in the right spot.
After reading comments like those MTV and others have made over time has shown me that my alignment difficulties wernt all my fault.

[jules456]

Am I allowed one more annoying question?

Setting up the LNB skew. The Strong one I have came with no instructions. It has little dashes on it kind of like a clock. I’ve assumed each mark/dash is 5 degrees. It seems to be pretty close. And I fine tune it once I get true signal. Does any one have one am I doing it right?


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[gordon_s1942]

Jules, use those markings exactly like the markings on a clock.
Make the top 12 and the bottom 6.
Professional members like MTV will give more details but until then, when rotating the LNB, do so nice and slowly generally starting with the co-ax pointing straight down and then turning it either clockwise or anti clockwise.
If your advised to set the LNB at say 10 degrees RIGHT, with you facing the dish, the co-ax would now be now roughly at the 5pm mark on a clock.
From what I understand, the incoming signal tends to twist as its reflected from the dish to the LNB.
By getting those angles correct, Azimuth, Elevation and Skew, you are collecting as much as the signal as possible and while other factors can and will block the incoming signal, you know whats available at the Dish is being sent down to the decoder.

[mtv]

Skew is simply matching the polarisation of the receiving antenna (in the LNB) to the transmitting antenna on the satellite.

Skew variation occurs depending on the receiving antenna's location relative to the satellite's position, due to the curvature of the earth. (doesn't apply to flat-earth nutters I guess )

Yes, the majority of LNBF skew markings are 5 deg, with the centre being 0 deg.

Some VAST decoders have inbuilt screens that display an approx skew setting for an approx location you enter... also elevation and azimuth settings.

Wth the coax connector pointing directly down when the LNB markings show 0 deg, we refer to the coax connector to be at the 6 o'clock position. (eg: it's pointing straight down)

All LNB skew figures/positions are considered to be looking into the front of the dish (eg: standing between the dish and the satellite... remember to move out of the way to measure signals though )

For VAST on Optus C1/D3 an LNB coax connector is typically around the 7 o'clock position for the east coast and moves further back towards the 5 o'clock position as your location moves towards the west coast.

So if you're in the eastern states, starting with the coax connector on the LNB set to around the 7 o'clock position is a good approximate setting... then fine tune adjustment as required.

The skew figures on LNB markings aren't really important, if you know 'roughly' where to set the skew to begin with.

I never use them.