4.8 E from North London

smiffie said:
Can't see it being the DM800, an 80cm is on the limit of the signal threshold for 5E, a slight misalignment and you will lose it. Try peaking the dish on a FTA channel in the positioner setup menu using the "Position fine movement" East/West function. You should be able to optimise the SNR and BER, be patient, the figures don't refresh instantly. I find the DM800 very tolerant to high BERs, some of my channels from 16E are watchable with 33% SNR and 9K BER without breakup.

60% from 28E is not good even from something like NME TV, I would expect 90-100% on BBC 1/2 from an 80cm. But when you've looked at the postioner setup menu, you will start to get the "feel" for dish alignment.
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Ive tried tweaking it on three sats (13e, 28e AND 5e) and I cant get any of them above 68% at best. Does it sound like that the dish may be slightly out?
 
newcomers2 said:
Ive tried tweaking it on three sats (13e, 28e AND 5e) and I cant get any of them above 68% at best. Does it sound like that the dish may be slightly out?
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At that stage, I'd have the ladder and meter out to ensure the alignment is correct. Connect the meter then pull slightly on the dish rim left/right top/bottom whilst watching the needle. Sounds like you've had the sat before, so perhaps the elevation has been moved up slightly by the wind. Once up there check for loose fittings/connections and play in the motor mount. After that I would test by start substituting the LNB, the cable and the box as a process of elimination.
 
I wouldnt have a clue what to do, I don't suppose there are any installers in the herts area that fancy having a look?
 
@jcm193

jcm193 said:
i actually get a better signal because i changed from dm800 to a vu+ so i cobsider the tuner in the dm to be very poor
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Remember the reported SNR on the screen is calculated by the software. On older DM800 images they got the dB to % coversion wrong and it always reported much lower SNRs than other receivers. The proof of the pudding is whether a receiver can still produce a reliable picture from a weak signal with high error rates. This is a function of the error handling software and the receiver sensitivity at the analogue stage, which we used to refer to as threshold measured in dB. It doesn't seem to get quoted anymore, but a low threshold dB figure was a good indication of a receivers' ability to pick out a weak siganl from the background noise.
 
Lets get this clear. You say you have no signal - Does this mean you have zero signal quality on the channels or theres still signal but the channels arent decrypting
 
In my experince the vu+ would lock on at a much lower snr rate around 32% compared to around 40% on the dm800,Ive no idea if its correct or not,but i can say that the dreambox used to show the mbc channels on 26e at 80% snr and Vu+ show`s it at 67% snr on the same tp both with perfect pictures.But i do know that the lnb has made a massive difference and i would recommend it to anyone..

smiffie said:
@jcm193



Remember the reported SNR on the screen is calculated by the software. On older DM800 images they got the dB to % coversion wrong and it always reported much lower SNRs than other receivers. The proof of the pudding is whether a receiver can still produce a reliable picture from a weak signal with high error rates. This is a function of the error handling software and the receiver sensitivity at the analogue stage, which we used to refer to as threshold measured in dB. It doesn't seem to get quoted anymore, but a low threshold dB figure was a good indication of a receivers' ability to pick out a weak siganl from the background noise.
Click to expand...
 
im definitely getting no signal as opposed to the channels not decrypting. I know that when there is no game on there will be a black screen, but I still used to get signal.

I went to my brothers last night who has just had a brand new sat installed (same size dish as me, same receiver and lives 5 mins down the road).

He is getting 20% better snr on all sats we tested and did initially get 25% on viasat xtraPL channnels, although after switching between sats, we could no longer get a signal on those channels again. Im guessing his dish should still be pretty much spot on as its only about 2 months old.

Think I may have go down the new dish and lnb route. Any recommendations on dish, dish size and lnb?
 
Mayne not a new dish but possibly new LNB and new co-axial cable.

I've just jumped onto this thread - how old is the setup?
 
The receiver is 1 year old and the rest is 3 years old. I'm pretty sure the dish is a technomate but not sure about the lnb
 
It's possible the LNB has had it. In hot climates you have to replace them sometimes every year but it'd be unusual for the uk.

I'd be more inclined to look at the cable. Has the F connector onto the LNB been properly waterproofed? Water ingress can cause signal degradation.
 
when you say cable do you mean the connections on the cable at the lnb end?

I remember having to cut the cable in the loft but that was joined again, would it be worth checking that part?
 
How was it joined?

Joints of most types are prone to poor screening, poor connection etc. and can result in loss of quality either across the board or confined to just a few frequencies.

Even a diligently made up F Barrel Connector arrangement isn't ideal.

Looking back over the Thread, I would suggest this join is a highly probable culprit.
 
Yes I did mean at the LNB end. Although now that you have mentioned this join, as Tivù says, this is a prime suspect.

If you're not sure take a couple of photos. Remember to upload them here rather than using Photobucket or Flickr.
 
Ok ive checked those joints in the loft and theyre all ok. I took them apart and remade them all to double check but still no difference.

As my brothers brand new setup is also unable to receive these channels, could it be our dished are too small?

Also, whats the general opinion on technomate dishes, as thats what our dishes are.
 
What method did you use to make these joints in the loft?

And, yes. If he can't get them either that's a distinct possibilty.

TM dishes are generally OK.
 
Ive joined it using 2 f couplers. The fella who I used to use for all sat related stuff came round after I made the joins and actually remade them for me with a new bit of cable too, so im guessing it should be ok. Problem is I cant get hold if him anymore to get him round to have a look!!
 
Further update, I tried to get 16E and couldnt get any kind of signal on any channels.

I was also looking back at some posts I made about this time last year on another forum, and I was getting about 90%SNR on 28.2E, and im now only getting 55%-60% at best, so something has definitely changed.

I have managed to get in contact with my sat man, and he says lately hes had a few cases where the lnb arm (sure thats what he called it) had gotten water in to it and frozen, damaging the arm and causing it drop slighly, causing signal problems. Does this sound like it could be the cause? He's also going to advise me about dish size for sirus.

I will update more once hes been Thursday evening.
 
Yeah definately looks like the dish has became misaligned by the wind or something else. Easily fixed.
 
My dish was moved due to the wind, not too badly, lost about 10% signal on 4.8E.

I need to realign, not had the chance but this time I'll focus it on 4.8E when I realign it, it's an 80cm dish and it only struggles with 4.8E when it rains :(
 
Update:

My sat man arrived, straight up the ladder to the dish, drilled a hole in the metal arm that holds the lnb and a hole load of water came out!! He said the metal arm had actually changed shape due to the freezing water. He has left the hole there so any future water will just drain out.

He realigned the dish, and now I have 90%+ SNR on most sats, and most important of all, I now have 4.8E back, with 50% SNR in the rain!!

Looks like my 80CM might just be big enough

Thanks guys
 
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