Signal quality on UEC DSD4121 VAST

[ajt]

Hi All,
My name is Andrew and I am new to this forum.

I am interested to know what peoples experiences are with the Altech UEC DSD4121 decoder which is being used for VAST, more specifically what sort of signal quality your decoder is telling you it is recieving.

Currently I have tried two different dishes, a 75cm and a 90cm and the best signal quality I can get is 42 (% I think as there is no unit of measurement displayed), across all VAST transponders.

The change from the 75cm to the 90cm only improved the signal by 1 (%)

While I don't have any drop out issues, I find it interesting that the figure is so low.

The Satellite finder / spectrum analyser I have is a Satlink WS-6912, while I realise that this is no top quality unit, I have found it to be very reliable, and its only down fall is that it does read a little on the high side with signal quality. In general from previous experiences with my motorised 2.3m C-band dish a reading of 99% signal on the satlink will transpond to a reading of approx 80% on either my topfield decoder or ST-gold decoders.

I'm wondering if this may be a firmware issue? (I have updated to the current version)

Any feedback would be greatly appreciated

Regards,

Andrew

[mtv]

I currently have 81% for Signal Level and 75% for Signal Power with a 65cm dish with dual output Sharp LNB.

Every decoder is likely to show different readings, due to the inaccuracy of signal measurements.

As you are aware, there is no benchmark for the measurement in the decoder, eg: dBuV and true BER.

If you have the dish aligned correctly, you need to ensure you have the LNB skew and focal point optimised, which is usually the reason for lower level readings from the VAST transponders.

If you have reliable reception, it really doesn't matter what the numbers say.

[Tiny]

The best I can register is 41 on signal quality with a 90cm dish with dual output Sharp LNB.

Have read in this forum of others still only getting signal quality in the 50's with a 1.2 m dish. So what your getting sounds OK.

Have been experiencing heavy rainfall for the last 2 days & checked out of curiosity since it wasn't dropping out; signal quality is down to 36 without dropout. Picture quality is still excellent via HDMI to Plasma on HD channels.

Can't tell you what signal strength now since they removed the percentage indication, leaving only the signal level bar, in the last firmware update. Looks like its around 80%
Can tell you that when I first set up the box it was 85%.

Hope that helps

[mtv]

Apologies for any confusion over my VAST box signal readings, as I've been advised by UEC that the trial fimware in my decoder measures/displays siignificantly differently to the current public firmware release and that a typical UEC VAST decoder displaying a signal quality of 41 (or above) is very good, so it looks like you have a very good signal, ajt.

Naturally, I would prefer actual measurements displayed in dBuV and BER/MER not simply as a number or (%) percentage as it doesn't really tell you much and for '41' to be considered very good just doesn't seem right to me.

Obviously, others also interpret seeing a signal quality 'figure' in the low 40's to be very low.

It looks like UEC are addressing this with the trial version of the firmware.

Edit: It appears Tiny may also be using a trial firmware version?

[toyboy11]

Well from my point of view(2cents worth) the signal bar does not refer to % and if you see how high it is on the bar then forget the number, different to other boxes, but a high level on the bar should indicate a good reading.
Mine varies if you watch it and that's normal. I get a fantastic picture best of all from my other boxes.

[mtv]

Mine varies if you watch it and that's normal. I get a fantastic picture best of all from my other boxes.

Yes, signal variations are normal.

As I said, providing you have reliable reception, the numbers (or length of the scale on a bar graph) don't matter.

[Tiny]

Well from my point of view(2cents worth) the signal bar does not refer to % and if you see how high it is on the bar then forget the number, different to other boxes, but a high level on the bar should indicate a good reading.
Mine varies if you watch it and that's normal. I get a fantastic picture best of all from my other boxes.

Actually the signal level bar on the current firmware gives signal level (signal strength) with no numbers. (It used to have numbers on the original picture freezing firmware just near it & they were %).
The signal quality number is separate & if you change your LNB skew the signal quality will drop significantly before any signal level is lost on the bar.

So for travelers & DIY home setups without a meter, point the dish at the known satellite position with what you think is a close LNB skew angle for your position, get as best you can on the level bar then adjust the LNB skew to get the highest possible signal quality number. This will give you the best picture with the least amount of drop out in heavy rain.

[mtv]

Actually the signal level bar on the current firmware gives signal level (signal strength) with no numbers.
The signal quality number is separate & if you change your LNB skew the signal quality will drop significantly before any signal level is lost on the bar.

So for travelers & DIY home setups without a meter, point the dish at the known satellite position with what you think is a close LNB skew angle for your position, get as best you can on the level bar then adjust the LNB skew to get the highest possible signal quality number. This will give you the best picture with the least amount of drop out in heavy rain.

Setting up a dish is harder with VAST, as the decoder has to go through a tuning process every time the power is disconnected from the box..... most annoying if you're a traveller, so you need to have the dish aligned and the skew sufficiently optimised before the decoder with even start the tuning process.. eg: before you can even see any signal graphs/readings.

Typical cheap sat meters won't give you any indication of signal quality when adjusting the LNB skew, so I agree it's good to learn approximate starting positions for LNB skew for the areas/s you will likely be located.

Another 'standard-non-VAST' FTA sat box is useful, as they retain the satellite memories and you can use the tuning screen to help align and optimise the dish & LNB skew.

[toyboy11]

And that's what i will be doing taking another box with me to get set up.

[mtv]

And that's what i will be doing taking another box with me to get set up.

See this thread:



A new tuning feature has been developed and will be released with the next/PVR firmware update.

It makes aligning a dish and tuning the decoder very simple.

[toyboy11]

Thanks mtv. Had an email back from them this morning answering my querie on the latest software and they told me that DSD SW:2.22.2103 is the latest and that there will be an update released within the next several weeks (hope it's not to long) and that the box will update automatically over the air. Sounds good, just have to wait.

[mtv]

Thanks mtv. Had an email back from them this morning answering my querie on the latest software and they told me that DSD SW:2.22.2103 is the latest and that there will be an update released within the next several weeks (hope it's not to long) and that the box will update automatically over the air. Sounds good, just have to wait.

At this stage, it appears the final firmware (UEC call it software) is in the process of approval by Optus and the broadcasters prior to trial and then all going well, will be released publicly.

The PVR functionality and dish alignment assistant will be part of that public release.

It's well overdue, but it's getting very close to fruition.

As most would have seen, I have bagged the UEC VAST box from the beginning. There are still some things I'd like to see improvements made on and have made those suggestions, which UEC have taken onboard, but overall, the functionality has come a long way and the new dish alignment assistant is excellent IMO.

[gordon_s1942]

There is a saying that the Camel is the result of a committee trying to reinvent the Horse.
Back in the 60's, BMAC was honored with this title when the employees took over the design of the brilliant Morris Mini and made simple maintanace like changing the Oil filter and petrol pump almost impossible and now I feel UEC is vying for this title with all these 'Fixes' that really should have been apparent from Day One if UEC is as competent a manufacturer as they would like us to believe.

I could never understand why the Info channel (800) was encrypted and not available to be used as a 'Tune'' channel the same way C1 is often located without fuss.

[mtv]

I could never understand why the Info channel (800) was encrypted and not available to be used as a 'Tune'' channel the same way C1 is often located without fuss.

The VAST info channel is not encrypted and can be tuned and displayed on any sat receiver capable of decoding DVB-S2/MPEG4 (basically, any FTA HD sat box)

[gordon_s1942]

Apologies to UEC etc as I misread that about ch 800 being part of the encryption as I couldnt find it with my old Humax, obviously because it isnt DVB capable.

[ajt]

I had a chance to put the spectrum analyser on my 90cm dish today just to see if I could improve my signal quality, I'm getting 67.2dB which is equating to 42 units on the DSD4121

Thanks for the feedback, I look forward to the new firmware being released and seeing what suprises there are in there.

Regards,
Andrew