Forum > DStv Forum Archive (12 May 2014) > DStv Products > Installation > Strength of signal vs. quality of signal
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  #1  
Old 2013-01-17 , 15:52
ItsJustJack ItsJustJack is offline
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Default Strength of signal vs. quality of signal

I noticed that a few channels on my HD PVR were blank (no video or audio) for no apparent reason - MTV, the news channels to name a few. There is no message about searching for a signal, just a blank screen.

Checking the decoder, I found that For the past week or so, the signal strength has hovered around the 10-15% mark while the quality of signal is around the 90% mark. The signal strength before was close to the 100% mark.

What can cause this? Is the dish itself misaligned or is it a cabling issue?

Last edited by ItsJustJack; 2013-01-17 at 15:58. .
  #2  
Old 2013-01-17 , 16:09
Geoff D Geoff D is offline
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I think we are all trying to find out what is causing these problems, why some channels show good values and others do not.

Yes very often problems are as a result of a misaligned antenna or issues with skew angle, but lately, there are just too many anomalies to simply claim all of them are due to these issues.

I would not be too quick to start checking this aspect.

Generally speaking, if the signal level is below 50%, ther decoder should not "lock " on the signal at all and then the quality value should be 0%.

if the quality is above 90% and signal level shown is less than 50% it just makes no sense at all.

In the pre Ocrtober days, we were pretty sure that a signal level of less then 80% coupled with signal quality below 90% and/or an unstable signal quality would point to skew angle issues and or a misaligned antenna.

Now we are not so sure anymore.

The best would be to first reboot the decoder, tune to a number of channels, HD and SD channels on both VER and HOR transponders and get some sort feel for the spread of values.

Then try and do a reset to factory defaults so that the decoder can re-initialise a number of things and see. If this does not work, a Flash Reset may be the solution and then one can start scratching.

If you wish send me a PM for more info.

Typically the channels to tune to are:

101 103, 105, 108, 117, 178 at least. this should give you a better indication.

Check for stable quality values >90% with good signal strengths.
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Win 10 Pro (64-bit) version 1703, build 15063.138
1.2m antenna, 8-way universal LNB, 2x6 MS, FSM permanently connected.
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Last edited by Geoff D; 2013-01-18 at 08:30. .
  #3  
Old 2013-01-17 , 17:06
gwalker gwalker is offline
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Quote:
Originally Posted by ItsJustJack View Post
I noticed that a few channels on my HD PVR were blank (no video or audio) for no apparent reason - MTV, the news channels to name a few. There is no message about searching for a signal, just a blank screen.

Checking the decoder, I found that For the past week or so, the signal strength has hovered around the 10-15% mark while the quality of signal is around the 90% mark. The signal strength before was close to the 100% mark.

What can cause this? Is the dish itself misaligned or is it a cabling issue?
some have found a rescan to resolve and others have required a factory default or the more drastic Flash Erase.

The best bet is to have the decoder tested if near an MC branch or with a friend or neighbour to discount / rule out the installation. Things like wind and Hail can cause a dish to go out of alignment, an over grown tree or plant in the way can also be an issue.
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  #4  
Old 2013-01-21 , 14:09
AndrewD AndrewD is offline
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This is very interesting and simlilar to what I am experiencing. When we got back from leave we had been struck by lightning. By swopping cables on the multiswitch I very quickly realised that it was U/S but wasn't sure whether the LNB was also gone. The SD shoowed very low strength (30%) but 100% quality so I assumed that the LNB had "issues". I replaced it and now the situation seems even worse. I have channels (vert or horizontal - cant remeber which) which show 3% strength but 100% quality and it is locked !!! This is the same on both HD and SD decoder.

I have no signal issues - all channels are perfect. But the low strength values remain.

I'm just hoping this is not a symtom of something to come ...
  #5  
Old 2013-01-21 , 14:29
Geoff D Geoff D is offline
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Here is a situation where another decoder may help to pinpoint the issue.

It could simply be measurement is now wrong.

Access to a FSM may help to prove where the issue is.
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Easyview, UEC 4T HD PVR, SD PVR, XV
Spare decoders: SD PVR(2), PACE HD PVR 4T, DSD 660, 1110, 1131, Explora 1
2 unmentionable FTA decoders
Win 10 Pro (64-bit) version 1703, build 15063.138
1.2m antenna, 8-way universal LNB, 2x6 MS, FSM permanently connected.
MS Edge 40 with MSEdge HTML 15

Last edited by Geoff D; 2013-01-21 at 15:41. .
  #6  
Old 2013-01-21 , 15:12
ItsJustJack ItsJustJack is offline
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I haven't had a chance to check if it is the decoder itself that is the problem.

But something strange did happen to me yesterday.

Watching the soccer on channel 213 yesterday (all channels were viewable BTW), a scheduled recording started on another channel and the screen went blank with no sound. Changing to another channel, the picture came back but going back to the original channel still a blank screen with no sound.

Rebooting the decoder sorted it out until I pressed the record button on another channel...

I have the Pace HD PVR.
  #7  
Old 2013-01-21 , 15:52
Geoff D Geoff D is offline
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Quote:
Originally Posted by ItsJustJack View Post
I haven't had a chance to check if it is the decoder itself that is the problem.

But something strange did happen to me yesterday.

Watching the soccer on channel 213 yesterday (all channels were viewable BTW), a scheduled recording started on another channel and the screen went blank with no sound. Changing to another channel, the picture came back but going back to the original channel still a blank screen with no sound.

Rebooting the decoder sorted it out until I pressed the record button on another channel...

I have the Pace HD PVR.
The 4 tuner?

Assuming there is nothing wrong with the LNB and/or MS, then the only possible issue is with the decoder.

But what is causing it to cut off access to the channel beinhg viewed when a recording starts? This decoder is supposed to leave the viewed channel and buffer intact, even when previously recorded material is viewed.

If there is a problem with the install, power is being cut or at least interfered with when the recording starts.

The only way i know of diagnosing this would be to try and measure what poer is delivered by the tuners when this happens.

the power feed on tuner 1 should stay as is when the recording starts and the power delivered from tuner 2 should reflect VER 13V or HOR 18V when the recording starts.

I use a T piece inseted into the cabling between the decoder and the LNB and a high impedance probe connected to a voltmeter to check the output voltage on the tuner cables.
__________________
Easyview, UEC 4T HD PVR, SD PVR, XV
Spare decoders: SD PVR(2), PACE HD PVR 4T, DSD 660, 1110, 1131, Explora 1
2 unmentionable FTA decoders
Win 10 Pro (64-bit) version 1703, build 15063.138
1.2m antenna, 8-way universal LNB, 2x6 MS, FSM permanently connected.
MS Edge 40 with MSEdge HTML 15
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