Are you serious? What meters have you used?park_gate said:The best meter in the world won't beat this final stage as you are align the dish with the equipment and difficult reception conditions that you will be using to watch TV.
Hokksund said:OK. I tried setting the skew off and aligning the dish and that help me get 90%Signal and 90% Quality on both 12207V 27.5, 2/3 (2B south) and
12480V, 27.5, 2/3 (2A north).
BUT STILL no 2D ...aaaaggh! Also tried 10832 H , but no signal. Is this possible?
I spoke with a guy earlier today who is 1 hour west from here and he gets BBC1 on a 1.2m dish, so my 1.6m should be fine...the signal weakens here around 20:00
i think i'll call an installer with a meter to come out and check for 2D
Huevos said:Are you serious? What meters have you used?
There is no such thing as minimum pixelization. Pixelization shows you are at the signal to noise threshold imposed by Shannon's theorem. If signal to noise gets worse there will be no picture at all. If it gets better the picture will be perfect, but you have no way of knowing how far above the threshold the signal to noise ratio is. With a professional meter you can see how far above the threshold you are even when there is a perfect picture and this allows you to get the alignment nailed. It also lets you predict how the dish will perform at different times of day as the satellite power goes up and down, and lets you predict if, for example, there is any rain fade margin.park_gate said:Yes I’ve very serious.
My reasoning is based on the theory that you can’t beat adjusting for minimum pixilation on the very equipment you are going to use to view with and at the worst time of the day for reception.
That's not true. If he is receiving channels from 2A then he is receiving signal from 2D, it's just that those signals are below the signal to noise threshold imposed by Shannon's theorem. If you plug in a decent meter with spectrum display the signal from 2D would be clearly visible. For example one of my dishes is 90cm. From this location that is far to small for 2D reception but on the spectrum display the signal is clearly visible and the signature looks the same as for a larger dish. To the receiver though this signal is invisible/non-existent. What this means is you can get almost perfect alignment of a dish on to a satellite the receiver can't even see. And if you know you have perfect alignment but no lock the dish is obviously too small.park_gate said:The OP is getting absolutely no 2D signal could you explain how a meter is going to improve things.
Huevos said:There is no such thing as minimum pixelization. Pixelization shows you are at the signal to noise threshold imposed by Shannon's theorem. If signal to noise gets worse there will be no picture at all. If it gets better the picture will be perfect, but you have no way of knowing how far above the threshold the signal to noise ratio is.
Huevos said:If he is receiving channels from 2A then he is receiving signal from 2D, it's just that those signals are below the signal to noise threshold imposed by Shannon's theorem. If you plug in a decent meter with spectrum display the signal from 2D would be clearly visible.
Right, so next time a client rings and asks for an alignment I'll tell them they will have to wait until the next torrential rain storm at 11ºclock at night.park_gate said:The important thing is do the adjustment under worst case conditions.
Huevos said:Right, so next time a client rings and asks for an alignment I'll tell them they will have to wait until the next torrential rain storm at 11ºclock at night.
I'm joking of course but I'm sure you can see why it is practical to have a device which shows how a system is going to perform under the worst conditions even though the worst conditions aren't the current ones.
Hokksund said:OK. I tried setting the skew off and aligning the dish and that help me get 90%Signal and 90% Quality on both 12207V 27.5, 2/3 (2B south) and
12480V, 27.5, 2/3 (2A north).
BUT STILL no 2D ...aaaaggh! Also tried 10832 H , but no signal. Is this possible?
I spoke with a guy earlier today who is 1 hour west from here and he gets BBC1 on a 1.2m dish, so my 1.6m should be fine...the signal weakens here around 20:00
i think i'll call an installer with a meter to come out and check for 2D
Vipersan said:I personally like the Digisat Pro ..
LCD display ..
2v LNB inputs ...
Diseqc control ..
an adequate range of menu functions..
and around £50
damned good value..
rgds
VS
Ebay item
270484505462
if you want to check it out
It's just a field strength meter, no demodulation. This bit of the description is laughable: "PLEASE TRUST THAT YOU ARE BUYING QUALITY EQUIPMENT USED BY PROFESSIONAL INSTALLERS THEMSELVES".park_gate said:I don't believe this will work for fringe 2D reception as you can't select a single transponder.
Hokksund said:well it looks like a pure alignment or feed horn problem , yesterday i got hold of a couple of old single no name LNBs. I connected one and just hung it in the hole where the feed horn should go and voila up comes a 2d signal , 10818. I then move it around and eventually got a 50/50 signal.
Then i cut the feedhorn off of the no name lnb and held it in front of the c120 Invacom and again up came the 2d signal on 10818. Not very accurate , but it tells me the Invacom is working correctly at least.
I then tried aligning with the feed horn and invacom for couple of hours , but no luck.
any ideas anyone? It is the original feedhorn , so should work, although i am tempted to try an adjustable feed horn , or just rig up a holder for a standard LNB.
Hokksund said:Hi Terry, Really appreciate all your posts.
It is the original feedhorn, as the dish has a round plastic holder it fits into. i held the std lnb and tried moving in and out, the best result was flush where the original feedhorn should be, so the focal point must be correct. I have tried adjusting the arms and i am pretty sure i have it at the optimum point.
Today i drilled three holes through the plastic feedhorn holder at 120 degree spacing and used three screws and bolts to hold the Invacom Quad lnb in place, it work quite well. I have 50% signal & 50% quality in the fog on 10818.
Also I borrowed a great Canal Plus receiver from a friend CDC-7000. Which allows you to easily select which satellite TP you are looking at, check out:
_http://www.canaldigital.no/TV/Parabol/Temasider/Landingssider/Mottakere/Canal-Digital-CDC-7000/
This really helped, because unlike my Pace , this gives you the reading even if not locked and you can see it fluctuating up and down in 1% variations. Blinding!
I am now going to get hold of a C120 MTI AP8 and try that with the feedhorn again, I am also considering buying a IDLB-SINL40-ULTRA-OPP or the twin.