Reducing/Stabalising Signal on DM800 clone

[ruddyrum]

OK, so after a long time trying to sort out glitches on HD channels I got them all working by installing some additional cooling to the tuner! (also did the cap fixes but that didn't seem to work... but a few extra fans work a treat)

I still have the odd glitch on Discovery HD which i want to work perfectly! After reading that many people have solved problems with inline amps, i decided to also buy one. It arrived yesterday (20 db inline amp from ebay) and finally got round to installing it today. After fitting it, literally all channels stopped working (tune failed) and the ones that did work, were unwatchable.

I recall someone on here saying that glitches may be caused by having too much signal! so how does one go about reducing it? I dont know if that will solve the problem though. Here are my signal percentages for my setup:

All HD channels show the following, snr varies between channels, but is ultimately stable - SNR: 61-69% AGC: 99% BER: 0%

The Discovery HD SNR seems to fluctuate a fair bit between 55 and 63 % AGC: 99% BER: 0%

How can i stabilise my SNR? Will reducing my sat signal be of any benifit? if so, how do i go about it?

Cheers

 

[Liam1611]

If you have a motorised dish you can always reduce your signal by moving it East or West slightly by adjusting your USALS/DiSEqC settings in the receiver, and the same applies to a fixed dish.

Regards

Liam

 

[digidude]

if the tuner becomes saturated (too much signal) itll fail, but, if you use an inline amp, and slightly offset your dish, youll also then amplify unwanted noise thats introduced

you could try the amp, then a few attenuators to knock the signal back down, but you may then find that strong signals are still too much

 

[Liam1611]

The two things that matter the most with a Digital signal is Signal Quality and Bit Error Rate, the higher the Signal Quality and the lower the Bit Error Rate you will have less/no glitches. What size dish are you using to pick up 28 East?

Regards

Liam

 

[ruddyrum]

Using a 90cm dish... Its odd that Disc. HD is the only channel that fluctuates. I have tried tweaking the LNB a degree or two which solves the issue, only problem is that when the motor moves across the arch, it wont pick up channels on other sats until i move the LNB back.

 

[JohnO1234]

hi m8,

I have a brand new clone. BL75 Sim 2.01 and L3 tuner.

I have a motorised setup with an 80cm dish. I get glitches STILL on the following channels.

Sky Sports 1 HD
Channel 4 HD

and maybe one more I can't think of lol

I know for a fact my Discovery HD is perfect haven't had a glitch on it. It is nothing to do with signal strength. I reckon it's to do with the build quality of the tuner. For instance I have 89-90% signal on discovery and 76% on Sly HD which is the worst for glitching.

JohnO

 

[Liam1611]

Do any of the other channels that broadcast on this transponder glitch in the same way. Please check these channels out and let me know, Sci-Fi HD, Disney Cinemagic HD UK and ESPN HD. If you have problems with the rest of them glitching then its a problem with frequencies around this range, a dead spot in the tuner. Turning the LNB adjusts the polarity and you are skewing the LNB to bring the channels in. Try channels on different satellites that broadcast around the same frequency, such as here, here and here. It sounds to me as though some of the components are failing at certain frequencies which need replacing or it could be something as simple as tweaking a pot.

Regards

Liam

 

[ruddyrum]

Well, Disney HD is also glitchy... Never realised, as i never watch it... Weird thing was that i had many more HD channels glitching before i applied some fixes, now its just these two channels

 

[JohnO1234]

Lets face it the tuners are crap!! lol

Has anyone actually bought an original tuner and put it in a clone. Are all the problems instantly fixed with glitching on HD channels?


JohnO

 

[ChrisUK]

I dont have any glitches at all now on any channels since I performed the Cap mod, rotated the internal fan (stops the noise), and added a dual external fan (Rev J tuner).

The inline amp is still on, but it does reduce your signal by about 20-30% - but all HD channels are working fine with it, so I've left it on