Freeview, picture quality, sat dishes and OFCOM

[RogerS]

There is a very interesting thread going on here that is putting forward a very well argued case that Ofcom aka the Govt are going to screw up digital television for all of us who watch it via a terrestrial transmitter. Picture quality on both SD and HD is going to nosedive because the Govt wants to try and sell off the analogue bandwidth post-switchover. ofcom want to stuff the existing bandwidth with more rubbish home-shopping channels and that means that the bandwidth available for the the channels will go down. Result - rubbish picture quality.

So - as I'm going through a complete revamp/forward planning exercise for the home AV systems - I'm reluctantly thinking that we'll need to get a satellite dish to pick up FreeSat.

I have a question. Are there any regulations (EEC/Health and safety/Building Regs/Human Rights/whatever other cockamamy daft regulations are out there) that say I can't fix the dish to my chimney?

 

[chris_d]

Hi Roger,

This link may be useful http://www.planning-applications.co.uk/Satelite Dish Info.htm.

Extract:

...if you do not live in a conservation area, a National park, an Area of Outstanding Natural Beauty or the Norfolk Boards...then you do not need to apply for planning permission to install a dish ... provided that:

- there will not be more than one dish on the building or in the garden;
- the dish does not exceed 90cm in size;
- if the dish is installed on the roof, it does not protrude above the highest part of the roof;
- in the case of an installation on a chimney stack, the dish does not exceed 45cm in size and is not higher than the highest part of the stack.

 

[RogerS]

Thanks Chris.

South Herefordshire? Is that a new name for Monmouthshire :wink:

Roger

 

[chris_d]

Ross-on-wye...

 

[yo_chuci]

most satellite engineers will put a dish on a chimney as a last resort.
not sure any will worry about laws but that law will never be breached anyway...

a minidish (sky type oval) is 43cm across. if a dish is on a stack it shouldn't be higher than it any way due to leverage forces from wind pos pulling stack down and it will get more affected by whatever is coming out of the chimney.

if at all pos do not put it on the chimney.
installers like an easy life and if it every goes wrong (which it will up there) then it'll be harder to fix and they might charge you more for the privilege.

remember a dish can be an inch off the ground as long as it has a clear line of site in the direction it is pointing (28.2deg east of south for freesat).
the angle of the signal to the dish comes in at about 24degs from horizontal.
i have put many a dish at ground level with a pot sheilding it from view and they work fine. generally dont get affected by wind etc.

also remember if you are gonna get the freesat box that can record you will need 2 feeds from the dish so get a quad lnb (bit on the end with 4 outputs) gives 2 spare for other rooms or encase 1 packs up.

any questions just ask.

 

[RogerS]

Thanks for the advice, yo-chuci.

The chimneys come out in the valley of the double-gable roof and so the fitter will be standing on a flat surface and fixing the aerial at chest height! We need to get it up higher than ground level because of the topology/trees. The preferred chimney stack puts the dish out of visibility and also not used for fires.

Good advice re the LNB. What sort of cable runs are recommended from the dish to the LNB and then from the LNB to a FreeSat box (most likely will be the Humax Freesat PVR jobbie). Is the LNB powered via the cables? Can it go in a loft?

 

[chris_d]

What sort of cable runs are recommended from the dish to the LNB... Is the LNB powered via the cables? Can it go in a loft?

An LNB is the receiver element at the focal point of the dish, hence the cable run starts at the LNB, so obviously the LNB can't go in the loft since it is fixed to the dish. And yes, the cable does power (and indeed tune) the LNB but that is done by your set-top box.

 

[RogerS]

What sort of cable runs are recommended from the dish to the LNB... Is the LNB powered via the cables? Can it go in a loft?

The LNB is actually the receiver element at the focal point of the dish, hence the cable run starts at the LNB and obviously can't go in the loft since it is fixed to the dish. And yes, the cables do power (and indeed tune) the LNB but this is done by your set-top box.

Set-top box? Is that the same as, for example, the Humax FoxSat-HDR?

 

[flying haggis]

Good advice re the LNB. What sort of cable runs are recommended from the dish to the LNB and then from the LNB to a FreeSat box (most likely will be the Humax Freesat PVR jobbie). Is the LNB powered via the cables? Can it go in a loft?

With ref to the cable runs from an LNB use the best quality CT100 coax cable that you can afford and if possible run from the LNB direct to the set top box without any joins but if you have to join the cable (say at a wall plate for neatness) use F connectors and joiners not coax plugs

cable like this http://www.screwfix.com/prods/22591/Ele ... xial-Cable

and connectors like this
http://www.screwfix.com/prods/17061/Ele ... Pack-of-10


and while you are on the roof you might as well connect all four outputs of the LNB while you are there and leave the unused cables unterminated in the loft ready for use in the future

 

[chris_d]

Set-top box? Is that the same as, for example, the Humax FoxSat-HDR?

Indeed it is.

HTH,
C

 

[dickm]

Sounds like Govt is doing/proposing all sorts of daft things with TV as well as FM radio then.
Up here in the wilds, terrestrial digital reception via amplified aerial and set top box to our old TV was just about OK, but not brilliant, so got a Humax satellite box and (after a lot of faffing) got dish lined up and pretty good reception. Then we changed the TV to a LCD one with built in digital, and the terrestrial receptionl was much better. But the satellite one was much worse.....

I'm too old for all these changes.

Oh, BTW, do any of you experts know whether a 25 m run of cable from a second terrestrial aerial to another part of the house has any chance of working? The layout is such that it looks like the only solution.

 

[RogerS]

Sounds like Govt is doing/proposing all sorts of daft things with TV as well as FM radio then.
Up here in the wilds, terrestrial digital reception via amplified aerial and set top box to our old TV was just about OK, but not brilliant, so got a Humax satellite box and (after a lot of faffing) got dish lined up and pretty good reception. Then we changed the TV to a LCD one with built in digital, and the terrestrial receptionl was much better. But the satellite one was much worse.....

I'm too old for all these changes.

Oh, BTW, do any of you experts know whether a 25 m run of cable from a second terrestrial aerial to another part of the house has any chance of working? The layout is such that it looks like the only solution.

I can understand why the new TV might be better than the old one with terrestrial since a lot of the freeview stb's are rubbish. But why it should be worse on satellite since you're using the Humax as your 'digital receiver'. How are you connecting the Humax to the TV? Can you elaborate as to why satellite is worse? Or describe the symptoms - asks one who used to be as close to the original broadcast camera signal as you can!

 

[yo_chuci]

it shouldn't be worse... it might be a connection thing...

a 25m run should be fine also.

 

[dickm]

It's connected to the TV (a 26" Panasonic) via Scart as per the instructions. The problem is that there looks to me to be colour distortion - reds much too red, and the picture doesn't look to be as sharp as the terrestrial one. Adjusting colour etc on the TV improves the colour rendering, but then has to be re-adjusted if I go back to terrestrial for any reason. And I still feel the picture isn't 100% sharp.

 

[RogerS]

Is your TV adjusted to pick up the RGB, component or the composite signal in the SCART? That will make a difference in quality - going from best to worst in my sequence.

 

[yo_chuci]

well said rog... it'll be settings or the scart lead itself...
if they aren't in true and square etc you can get alsorts of colour issues...

check on the sat box is set to the right output (rgb)
and depending on which scart socket on the tv you are plugged into check the settings for that in the menu as scart 2 can sometimes be set to receive s-video etc so colours can be off..
try a diff scart also... they can work fine in 1 tv but then not in the next. dunno why just saw it alot when swapping sat boxes.

 

[dickm]

Is your TV adjusted to pick up the RGB, component or the composite signal in the SCART? That will make a difference in quality - going from best to worst in my sequence.

er..... I think I need to go and read the instructions......

(told you I was too old for this sort of thing )

 

[TrimTheKing]

Also, if you are using the scart that came free with any device (other than super high end kit) then you might as well be using a piece of tin foil. Buy a decent scart, doesn't have to be mega expensive, a tenner will get you something 100 times better than the rubbish they provide free with TV's etc.

I experimented with all of this a long time ago, buying up to £80 scart cables, and scarts with only the video pins wired (audio going through digi coax) to stop crosstalk. I used the expensive one because I had paid the money, but in honesty there wasn't all that much difference between the £10-£15 one and the £80+ one (well, there was noticable difference when using DVD's but not to warrant the money).

On the other hand, the difference between the £10-£15 one and the free one was the difference between being blind and given back your site...I imagine

HTH