SNR on boxes - is it worth going by it?

dankargo

Specialist Contributor
Joined
May 11, 2014
Messages
727
Reaction score
453
Points
63
Age
33
Location
Brentwood, UK
My Satellite Setup
90cm Motorised
My Location
Brentwood
Hi all,

So, for the past year I've been using an Openbox V8S with my 80cm motorised system. Since it was in use every day, I got used to its signal readings on channels - for example the SVT HD channels on 1w would peak at a solid 70% and the TRT HD channels at 42E would peak at 78%.

The box started crashing a lot since last week, even after rebooting and changing power supply so I'm now using my back up Vu+ Zero receiver as the main one. For the part, its been working fine so far - motor moves to where it should but I've noticed the signal quality readings are quite different compared to the Openbox. The SVT HD channels at 1w are now fluctuating between 63-67% for example yet the TRT HD channels at 42E are moving between 91-94%.

This is using the exact same latitude/longitude settings on both boxes. I also did a 'Go to 0' when I swapped over boxes, just to ensure accuracy.

So my question is really, is the SNR recorded an accurate reading? I'd ideally like to get SVT back to a peak of 70% which it was on the Openbox but at the same time wondering if its really worth attempting if there's not much in it.
 

Lazarus

Retired Moderator
Joined
May 29, 2009
Messages
27,078
Reaction score
8,664
Points
113
My Satellite Setup
80cm Motorised.
Several small Dishes.
Much else.
My Location
North York Moors
No, you can really only use these readings as a crude guide.

You cannot compare the readings from one box type with another, owing to the metering being differently constituted and also affected in unpredictable ways by the AGC.

At the end of the day, if you have full lock in all but the most severe conditions, that's all you need.
 

Mickha

Super Moderator
Staff member
Joined
Dec 10, 2004
Messages
5,974
Reaction score
884
Points
113
My Satellite Setup
1.2M Channel Master, 1224 motor, VU+ Duo 2
My Location
North West
You can get different readings using the same receiver, I have the VU+ Duo2, and I've noticed different SNR readings, from when I had Blackhole loaded, to now that I have Open Blackhole loaded.
It just shows how useless the quality readings can be, except for peaking your dish.
What image do you have loaded, on your VU+ receiver, dankargo?
I'm not sure how good the VU+ Zero is, as I think it was built as a second receiver option, to a more expensive VU+ receiver, similar to a sky second receiver option, but check out the Plugins options, if available, the IPTV Player is a simple plugin, that provides quite a bit of internet viewing, as is kodi 17.3 krypton, once set up.
 

dankargo

Specialist Contributor
Joined
May 11, 2014
Messages
727
Reaction score
453
Points
63
Age
33
Location
Brentwood, UK
My Satellite Setup
90cm Motorised
My Location
Brentwood
Thank you both for the fast responses :)

You can get different readings using the same receiver, I have the VU+ Duo2, and I've noticed different SNR readings, from when I had Blackhole loaded, to now that I have Open Blackhole loaded.
It just shows how useless the quality readings can be, except for peaking your dish.
What image do you have loaded, on your VU+ receiver, dankargo?
I'm not sure how good the VU+ Zero is, as I think it was built as a second receiver option, to a more expensive VU+ receiver, similar to a sky second receiver option, but check out the Plugins options, if available, the IPTV Player is a simple plugin, that provides quite a bit of internet viewing, as is kodi 17.3 krypton, once set up.

That's interesting to hear. I have Blackhole installed on my Vu+ Zero. Yep i've been told by a few that its not the best receiver, though I actually quite like it I have to say, as a single tuner and the ability to record to external drive is all I require. Not heard of Open Blackhole, is that any better than the default Blackhole image?
 

Mickha

Super Moderator
Staff member
Joined
Dec 10, 2004
Messages
5,974
Reaction score
884
Points
113
My Satellite Setup
1.2M Channel Master, 1224 motor, VU+ Duo 2
My Location
North West
I liked Blackhole, but it only has kodi 16.1, so I switched to Open Blackhole, which has kodi 17.3.
In Blackhole I used the IPTV player, vumoo being one of my favourites.
Blackhole is based on the official VU+ image, whereas Open Blackhole has more freedom, for other developers to add to it.
If/when Blackhole gets the latest kodi version installed I might change back, but at the moment Open Blackhole is working fine.
 

Terryl

Specialist Contributor
Joined
Apr 14, 2011
Messages
3,246
Reaction score
1,932
Points
113
Age
82
My Satellite Setup
OpenBox X5 on a 1 meter motorized dish.
And now a 10 foot "C" band dish.

Custom built PC
My Location
Deep in the Boonies in the central Sierra Nevada mountains of California.
The only way to get an accurate SNR measurement is in a Lab with known good test equipment.
 

MCelliotG

Specialist Contributor
Joined
May 10, 2015
Messages
1,012
Reaction score
1,199
Points
113
My Satellite Setup
TBS 5925, Mut@nt HD51, EDISION OSMINI, MABO 130X144, DRAGONSAT DS3000 LED MOTOR, INVERTO BLACK ULTRA TWIN LNB
My Location
Thessaloniki, Greece
The rule is simple: stay away from percentages. They can never be accurate and comparable, in fact they are meaningless, the snr is a value that shows C/N (carrier to noise) which is a boundless (limitless) value which is measured in db. So what a percentage measures? Of what?
Only some PC cards can display a quite accurate db value and a few selected E2/non E2 receivers (it all depends on the tuner hardware and drivers).
And for God's love never trust VU+ boxes, they don't care about db readings and the driver always returns a limited digital value which is then converted to db and it's always wrong even when a part of it gets close.
Anyway in conclusion receivers are not pedometers, and a user will never need 1000% accurate professional readings. If the receiver can measure SNR quite closely to a professional value and the SNR is boundless then it's more than enough in all cases.
 

Channel Hopper

Suffering fools, so you don't have to.
Staff member
Joined
Jan 1, 2000
Messages
35,533
Reaction score
8,554
Points
113
Age
59
Website
www.sat-elite.uk
My Satellite Setup
A little less analogue, and a lot more crap.
My Location
UK
Anyway in conclusion receivers are not pedometers, and a user will never need 1000% accurate professional readings.

Must.....resist.....
 
Top