LNB's - Is there any difference

Posted by: Yantoe on 09 September 2005

We've always had a disappointing Plasma picture from satellite and having just broken our LNB (whilst building a new listening (watching??) room) we wondered if there's any outstanding LNB or perhaps Sky box we should seek out.
Sound all goes through a 252/SC,CDS3/XPS2, 135's, Isobariks but next upgrade is probably AV2.
Guidance welcome!

Cheers
Yantoe
Posted on: 11 September 2005 by SimonJ
Hi Yantoe, welcome to the forum,

Disappointing picture from satellite, surely not!! Smile

I don't think an LNB will make that much difference as it's more to do with the lack of bandwidth used in the transmitting of the satellite picture. You'll probably notice that BBC News 24 has a better picture than most and this is due to them using a higher bandwidth than some other channels. Problem, is some HiDef plasmas, particularly I've notice Pioneer, are a bit too ruthless in their detail presentation and a bad source shows up too easily. Your best option for a better picture is either wait for HiDef Sky (This is likely to cost £500 for the box + higher monthly subscription) if your TV can accept it, get a sclaer to improve what you have (I've done this and the improvments are amazing) or maybe try a freeview/top-up-tv box if it has the right channels as from what I have seen the freeview picture is not as bad as satellite.
Posted on: 11 September 2005 by Yantoe
Thanks Simon,
I guess a "sclaer" is a scaler ??????
We've done lots with the internal wires etc which has had a significant effect and we did originally change the LNB from Thompson to Skyware (Phillips). However we still get patches of "soft" focus particularly on faces in e.g. crowd scenes.
The signal strength seems around 60 - 70 % of Max on the diagnostic on the Plasma so we wondered about a different LNB or maybe a proper (bigger) dish.

Any thoughts welcome!

Cheers

Yanntoe
Posted on: 12 September 2005 by SimonJ
Yes sorry, scaler not sclaer.

I think on Sky digital, as long as your picture is not breaking up then the signal strength is not the be all and end all. If it's locked onto a signal then a better LNB and/or bigger dish to increase signal strength is unlikly to improve things much if at all. If your LNB was functioning fine before then I think your problem maybe that your plasma is just showing up how rubbish some Sky channels can be, source first rule etc... If you have to buy a new LNB anyway, then I think you need to make sure the LNB is designed to work with your dish as not all dishes are the same. If the LNB is not dsigned to work with your dish, then the focus is not always correct. You should not for instance, use and LNB desinged for a mini dish with a 90cm dish etc.. I heard somewhere that Grundig LNB's are good.
Posted on: 12 September 2005 by Yantoe
Thanks Simon - we'll check out the Grundig but I suspect you are right - ah well life's never simple!
Cheers
Yanntoe
Posted on: 12 September 2005 by Edo Engel
Yan(n)toe,

The quality of your LNB will contribute to the functioning of your entire sat system (which is a bit of a binary matter), not to picture quality. If you find that picture quality is disappointing, there are the following options:
  • The DACs in your SkyBox are cheap.
  • The cable from your SkyBox to your plasma needs improvement (use a good RGB cable).
  • Your plasma will work best when calibrated (e.g. ISF).
  • The channels you watch have bad picture quality to start with or are transmitted with very limited bandwidth (see earlier posts).

I really think the fourth option is most likely. I recently compared satellite to cable (which I've never been really happy with) on my calibrated display (good 100 Hz telly) and concluded picture qualities were on par. Satellite picture was a tad cleaner, but also had quite a bit of digital noise accountable to bandwidth limitations.

Cheers,

Edo
Posted on: 12 September 2005 by Steve2701
You may also like to check that your sky box is actually outputting an RGB signal. Most dont as standard & need to be changed in the setup menu.
Doing just this first made a definite improvement on my panel, followed by high quality connectors.

PS.. If you do use a scart lead that is wired purely RGB you wont get any sound........ fully wired scarts can give both sound & RGB capability.
Posted on: 12 September 2005 by Edo Engel
quote:
PS.. If you do use a scart lead that is wired purely RGB you wont get any sound........ fully wired scarts can give both sound & RGB capability.

...which might be detrimental for your picture quality. I would really make sure my scart lead was purely RGB and get a separate sound lead from the DVB box to the Hi-Fi.

Cheers,

Edo
Posted on: 12 September 2005 by Yantoe
Thanks all,
The Thompson Skybox is attached via QED Scart to a QED QSYNC with its own power supply which converts the signal to RGB which then enters the Plasma via the PC input. We tried all sorts ad this gave the best picture.
????
Yanntoe
Posted on: 13 September 2005 by Edo Engel
quote:
????
I'm starting to think you're not going to get where you want to be. Satellite boxes happen to have mediocre output quality as opposed to, say, DVD players. Calibrating your screen will defintitely help but not really compensate for a bid signal. The one thing people really seem to be agreed about is that satellite providers spend too little on bandwidth to deliver a proper signal.

Cheers,

Edo
Posted on: 13 September 2005 by SimonJ
quote:
Originally posted by Yantoe:
Thanks all,
The Thompson Skybox is attached via QED Scart to a QED QSYNC with its own power supply which converts the signal to RGB which then enters the Plasma via the PC input. We tried all sorts ad this gave the best picture.
????
Yanntoe

If it's chanel quality, ie BBC News is much better than UKGold etc, then replace the QSYNC with a scaler and output from the scaler into the PC input on your plasma, you'll see huge improvements, I promise! Winker
Posted on: 13 September 2005 by Yantoe
Thanks - any suggestions as to a scaler and the likely costs? I thought they were in the "arm and leg" territory pricewise.
Cheers
Yanntoe
Posted on: 13 September 2005 by John Sheridan
quote:
Originally posted by Yantoe:
Thanks - any suggestions as to a scaler and the likely costs?

you could try one of these it works quite nicely on my digi tuner.
Posted on: 13 September 2005 by SimonJ
quote:
Originally posted by John Sheridan:
quote:
Originally posted by Yantoe:
Thanks - any suggestions as to a scaler and the likely costs?

you could try one of these it works quite nicely on my digi tuner.

That's the kind of item he already has. Simple scalers start at £500-600 for base Lumagen or DVDO-iScan.
Posted on: 14 September 2005 by domfjbrown
What box are you using? If it's not a Panasonic, give up on the picture quality Winker

If it's Amstrad or Pace, you might as well through it in the bin...