View Full Version : Low AGC?
Hi,
I recently installed a 65cm solid Technomate dish and Unicable II LNB, along with a VU+ Uno 4K SE and GiGaBlue 4K Trio. I fiddled around for ages with the dish alignment, using various apps, a compass, an inclinometer and adjustable set square. SNR (for Channel 4) is 100% but, AGC is only 11. Should it be higher? And if so, how can I get it higher?
I've read that checking alignment against the '4 quadrants' is advisable bit, what are the 4 quadrants? A service/ channel to represent each would be useful information.
I have no issues with drop outs, I'd just like to get the dish 'perfectly' aligned.
Cheers,
Paul
Stop worrying about AGC - totally immaterial - just use the SNR to tune - and don‘t try comparing SNR to another box -not valid
Hi,
I recently installed a 65cm solid Technomate dish and Unicable II LNB, along with a VU+ Uno 4K SE and GiGaBlue 4K Trio. I fiddled around for ages with the dish alignment, using various apps, a compass, an inclinometer and adjustable set square. SNR (for Channel 4) is 100% but, AGC is only 11. Should it be higher? And if so, how can I get it higher?
I've read that checking alignment against the '4 quadrants' is advisable bit, what are the 4 quadrants? A service/ channel to represent each would be useful information.
I have no issues with drop outs, I'd just like to get the dish 'perfectly' aligned.
Cheers,
Paul
AGC is Automatic Gain Control
High input signal low AGC value
Low input signal high AGC value
Having a lower AGC value probably gives more margin for a lower signal when it rains etc.
Why would you want to degrade your input signal to get a higher AGC value? :)
The 4 quadrants probably refers to high/low/horizontal/vertical. For a convetional LNB the box will send signals back up the cable to select each mode.
You can get the box to do this by tuning/selecting different channels. Some channels are on horizontal low band, some on horizontal high band, some on vertical low band and some on vertical high band.
https://www.soontai.com/da_satelliteTVrec.html
The V and H designations in the following table are the channels on Horizontal and Vertical polarisation Low/high band can be established from the column labelled "IF Universal LNB" ( the L and H at the end of the numbers indicates Low/High)
http://en.satexpat.com/tv/uk/freesat/
This is what it should look like.
60131
This is what it should look like.
60131
Possibly the more important paramenter is BER (Bit Error Rate) which ideally should be zero (zero errors)
Thanks for the responses.
I had a read around, prior to seeing this and found the Enigma2 Satfinder app. Then had a look through the channel listings for low SNR channels. First one I found was The Horror Channel at 78%. So had a tweak of the LNB skew (and LNB distance from the dish), elevation and then Azimuth and got it to 100%, without fluctuation. Took another look through the channels and found CNN at 79%, which I understand is on a 'weak' transponder. Further minor adjustment of all 3 attributes and I got it to 81%. So I think the alignment is nailed now.
In my set up, AGC seems to be about 10% of the SNR value and I've never seen a BER of anything other than 0.
Paul
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.