Problems with new digital decoder

[rochelle1972]

Hi all,
Ok I know absolutely nothing about satellite tv etc and I am starting to get a bit desperate so I am hoping someone will have a suggestion for me.

We have had our dish for about 5 years and had the old analog decoder. One of them died (we have 2 set up) a few months ago so the tv place suggested we buy the new digital ones.....so we spent $600 on 2 digital decoders. they are the proper ones altech whatever. When we had the old decoders the picture would go all pixelly only when it was pouring with rain. From the moment we put the new digital decoders on they went pixelly and constantly lose signal even in perfectly clear weather. I have called the tv place where we bought them from numerous times and they have no suggestions for us and want to come and have a look but will charge us $200 for the priveledge. So not totally happy about that one. They say it wouldn't be the decoders as they have had no other complaints except for ours. Go figure! We have no trees or high buildings around. When it stuffs up on most occassions ABC1 and SBS1 still work well. Which is weird to me. If it was a problem with the dish or the LNB then wouldn't they be the same stuffing up as the commercial channels do? I have been up on the roof and had a look at the LNB and it looks pretty much in perfect condition. The sticker has peeled away from it but other than that it looks fine. Is there a different signal strength with the ABC and SBS channels compared to the commercial channels. I have checked the signal strength when the commercial channel is working and it says 21. Not sure if that is normal or not. I guess if it is a signal problem I am wondering if there is a way to work out if it is the dish that is slightly out of alignment......maybe in a storm it has gone off line or something or do we need a new LNB. I've noticed they are priced around the $40 to $50 mark and certainly don't mind buying a new one of those. Can a normal person put a new one on??? Or do you have to know what you are doing with satellites to be able to put it on? Any ideas would be sooooo helpful. Thanks so much for reading my post!
Rochelle

[mtv]

Dish and LNB alignment is more critical than for most other signals.

Size of the dish is also important, and although a 65cm Foxtel/Austar dish works, I've found 85cm dishes to provide far greater reliability with VAST signals.

LNB's can deteriorate internally, not just visibly externally.

Water/moisture ingress into connectors/cables will certainly cause signal deterioration, so if your connections to the LNB were not sealed with self-amalgamating tape, this may also be an issue and if it is, the connectors and possble some cable may need replacing.

From your description, the likely issue is dish/LNB alignment.

Yes, it's possible to do the alignment yourself, by watching the signal scales on your screen whilst making very small adjustments.

To begin with, don't loosen anything, but flex the dish, left/right/up/down and observe any signal improvement.

This will indicate which direction the dish needs adjusting.

The same with the LNB... very small turning adjustments.

When making any adjustments, you need to wait a few seconds for the decoder display to catch up.

The LNB may also be able to be moved forward/back in the holder, so this position needs to be checked as well.

These adjustments are not as accurate as professional instrumentation can provide, but they can help.

You haven't mentioned your location, which may indicate the best dish size required.

[OSIRUS]

Hi rochelle1972,

It Sounds like you have a Altech DSD4121 Vast STB

Signal Quality needs to be in the high 30's (about 36 to 39 or more) to get a good reception on a Vast STB

What size Satellite Dish do you have?

some installers are recommending an 85cm dish's for adequate reception of Vast, depending on your location.....

I think The Dish needs to be Fine tuned to increase your Signal Quality, (including LNB skew) to the Maximum Signal Quality you can get, (basically fine tuned for the Vast STB & services)

Vast needs a better dish signal than does the old Aurora service, to get Pictures,

I would get a professional installer to fine tune your dish, for you (& take metered measurements to ensure the Signal Quality is maximized for vast)

An installer could also make recommendations on your Dish size, & condition of your LNB etc... or if there is a problem with your Vast STB

cheers

[rochelle1972]

I'm not sure what size it is. It is whatever they installed about 5 years ago with the analog decoder. Is the size just the measurement from one side to the other side? I will have to get back up there and measure it. Ok so the strength obviously isn't good enough for it. But why would SBS and ABC be ok? It just is weird!

[rochelle1972]

O and my location is post code 6275

[rochelle1972]

Dish measures 85cm across. Assuming this is how you take the measurement!!!! So I guess we have the correct size. I'm not keen to try to muck around the direction etc. The local electrician installs dishes (he didn't do ours) so I am going to assume he would have the right equipment. Weird thing is that the picture is perfect this evening! Even after having a wiggle earlier this afternoon the picture was still being stupid but now its perfect. The signal strength is still 21.

[beer4life]

O and my location is post code 6275

Let me guess, that's around " Nannup " WA.
Why the secrecy?

[toyboy11]

As mtv and osirus said it sound like your dish is out of alignment a wisker you should be getting around 65% signal and because you are getting a stronger signal on ABC etc that's because they transmit at a higher frequency which with a vast box is hard to determine individual transponder strengths.

Check your dish alignment.

[rochelle1972]

There was no secrecy about where I live at all. Not many people would know where Nannup was so thought it would be better to put the post code. I've seen other threads here where people put the post code.

[beer4life]

As mtv and osirus said it sound like your dish is out of alignment a wisker you should be getting around 65% signal and because you are getting a stronger signal on ABC etc that's because they transmit at a higher frequency which with a vast box is hard to determine individual transponder strengths.

Check your dish alignment.

Just to clarify your misconceptions

The STB responds to the Band of frequencies, either H or V and although it may appear so, is not selective of individual transponders, unless selected for a specific scan, Manual, Blind or Network.
Using a Spectrum Analyser is a different kettle of fish.

[joezep]

The easiest thing you can do is mark a line on your lnb and loosen it to finger tight. Turn your lnb by millimeter/s each way and watch the signal and peak it. If all fails line it back to the line you marked. The skew is very critical for Vast more so than Aurora

[mtv]

VAST uses several different transponders, so theye may be a slight variation of signal readings between them.

This is not usually noticeable when there is sufficient signal strength and quality, however, when signal levels are very low, as in your case, even the slightest variation, such as weather changes, even between day and night, can cause the slightly weaker signals to drop below the minimum threshold, pixellating or not being decoded at all.

Hopefully your local electrician/dish installer has the correct equipment to measure satellite signals accurately.

I'm also a little puzzled by your reference to your previous 'analogue' decoder.

If you are referring to Optus Aurora, that system is digital, not analogue.

If it isn't Aurora, I'd be interested to know what it was you were receiving in analogue.

[rochelle1972]

It was aurora which I assumed was analog or whatever the old system is. We couldn't get the new channels Gem etc on the old box but had abc 1 and sbs 1 from all states. If it was already a digital box then why did we have to get the new altech one? Why didn't the aurora box receive the new channels. Hence my assumption that it wasn't digital. As I said in my first post I really have no idea with this satellite stuff. I found this forum in my search for answers and was hoping to get some ideas as to what the problem could be. The tv place isn't very helpful. We weren't allowed to talk to a technician about the problem, even though they know we live about an hour away. I understand they need to charge the large amount if they come to look which she couldn't even tell me exactly how much. A $99 call out fee, plus travel which she couldn't tell me how much that would be, and I am assuming the time the technician spends here at some amount which I would assume would be around the $100/hr mark. So not having any idea of what it was going to cost us I really didn't want to go down that track. I think we would have been up for a minimum of $200 but more likely $300. As I said before we have already spent $600 on a product that isn't working properly and they won't even give us any ideas over the phone. and of course we are the only customers that have had this problem! Either they don't have a lot of customers that have installed these decoders on an older dish or they are fibbing to me! The electrician who has the gear for the satellite can't come for about 2 weeks! and then he will probably forget anyway so I will have to hassle him every 4 or 5 days, hence taking more time. I am on leave for 2 weeks - thank god there is nothing decent on tv anyway tho I enjoy watching the cricket! I guess it is possible that the dish was never installed properly by the original installer - which is a branch of the store that I have been calling about the problem! As you have said that the old system didn't seem to need to have as strong a signal. I might get up on the weekend and fiddle with the LNB and put the line on it etc. Which bit unscrews? The white cap??? I didn't fiddle with it yesterday due to the fact I didn't want to completely lose everything......tho in saying that I can only put the tv on the ABC or SBS this morning.......won't pick any of the commercial stations up at all......keeps searching for signal. Last night was perfect reception.
Thanks very much to all who have made a contribution. I really do appreciate your suggestions.

[OSIRUS]

Vast is different from aurora in that it delivers some High Definition Channels & 16:9 picture ratio,

it also uses different Video compression system, (DVBS2 & H.264) giving better picture quality at smaller file size (which I think they can then fit more channels into the bandwidth)

Vast also uses a new Encryption System & various security measures, dictated by the Broadcasters & the Government,

which meant that they had to have new hardware (set top boxes) to deliver the new broadcast requirements,

which also means you can only use the Vast card in the vast supplied STB,

Vast mirrors the Terrestrial Digital Freeview Channels that People get from Terrestrial FTA, in number of channels & content & broadcast Quality

Aurora was a digital satellite broadcast signal but used a slightly different encryption, etc.... & roughly (not exactly) mirrored the Terrestrial Analog channels

[OSIRUS]

As I said before we have already spent $600 on a product that isn't working properly and they won't even give us any ideas over the phone.

$600 is a lot of money to spend.....

was that just for the Vast DSD4121 Set Top Box ?

or did that include installing the dish etc..... as well ?

and of course we are the only customers that have had this problem! Either they don't have a lot of customers that have installed these decoders on an older dish or they are fibbing to me!

I have got a Foxtel installed dish here on the East Coast & the Vast STB works Fine with it,

also an installer will often optimize the signal Quality of the Dish for the Service it was installed for

(i.e. fine tuned for Foxtel Services, or Fine tuned for Aurora Services)

Other people find that their dish is not aligned good enough for vast reception,

even though it was working OK with another Set Top Box on another service

It may not be a dish alignment problem, it may be an LNB problem or a cabling problem, or something else,

but you have got to start somewhere, & then it is a process of elimination as to what the problem is

I hope you get it sorted out

Cheers

[Tiny]

$600 is a lot of money to spend.....

was that just for the Vast DSD4121 Set Top Box ?

or did that include installing the dish etc..... as well ?

OP said
2 decoders for $600.

[Tiny]

I might get up on the weekend and fiddle with the LNB and put the line on it etc. Which bit unscrews? The white cap???

Not the white cap.

The clamp holding the LNB is just behind the white cap, just loosen the screw/s a bit then adjust one way or the other in very small increments.
Your current picture quality of 21 is borderline dropout quality, this is definately your problem.
As stated by OSIRUS in post #3 , you need to get the Picture quality reading up to 36 or 39 would be even better. Best I can get is 41.

[rochelle1972]

The $600 for 2 decoders.......I've rounded it up as it was $290 ea. But then we had to travel the 50km to go and get them as well!! So I guess it was probably over that really! I was going to buy them online as they were cheaper but I thought just in case there is a problem better to get them from a local supplier - well that wasn't such a good plan as they don't want to know us anyway! My friend has to get one for her system in Augusta so I won't be recommending that mob to her. She is better off getting on online!

[Guiseppe]

Dish and LNB alignment is more critical than for most other signals.

From your description, the likely issue is dish/LNB alignment.

Yes, it's possible to do the alignment yourself, by watching the signal scales on your screen whilst making very small adjustments.

1. To begin with, don't loosen anything, but flex the dish, left/right/up/down and observe any signal improvement.

This will indicate which direction the dish needs adjusting.

2. The same with the LNB... very small turning adjustments.

When making any adjustments, you need to wait a few seconds for the decoder display to catch up.

The LNB is held in place by a split collar that has two small bolts and nuts holding it together.

If 1# indicates that the signal cannot be improved then:

- mark the collar and LNB somehow so that you know the current position
- loosen the LNB bolts only sufficiently that the LNB can be turned by hand i.e.still plenty of friction and then rotate the LNB one way by a millimetre or two. Wait for the box to respond. The change in signal strength will indicate if the rotation was correct or not. If it goes down then rotate the LNB the other way a millimetre or two beyond the original position.

Conversely if the signal strength goes up then repeat another millimetre or two in the same direction.

[admin]

rochelle1972, as mentioned it is likely to be your dish alignment and LNB skew.

The reason you have some channels fine and problems with others is that it basically needs "fine tuning".

The LNB (which is on the end of the dishes "arm" and has the cable connected to it) more than likely need fine tuning, so the dish may also need a slight realign as well. This mainly involves turning the LNB to give the best readings for all channels.

Any half decent satellite installer should be able to rectify your problem at a reasonable price. I would recommend getting someone out if you have not done it before.