Fitting aerial socket

simonpearce said:
yeah - that wouldn't work. I can't explain why though!!!

On a normal TV signal, all frequencies (474-858 MHz) are received by your antenna, sent down your wire (unamplified) and then the filters in the front-end of the TV select your correct channel (BBC1, BBC2, etc.)

With satellite, the signal is much too high in frequency (14-14.5 GHz) to pump round your house on a wire, so it is converted down to something much more cable-friendly, amplified and then sent down the wire by the LNB. To make the electronics cheaper, it uses a control signal from your decoder to select just the narrow band of frequencies that your required channel occupies, rather than sending all channels down the wire (broadband microwave amplifiers are expensive, or at least expensive in terms of free stuff that Sky gives you when you sign up).

So each channel needs its own LNB. Though the frequencies are very different, think of each LNB as being like a separate Freeview box - different one required for every channel you want to watch.....
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OK - now it all make sense, thanks for that.

Sky is still a bagoshite though....
ban-all-sheds said:
Sky is still a bagoshite though....

absolutely . . . and don't get me started on their pricing!

problem is, I really don't think I could live without sky+ now though :( Being able to pause and rewind is great and it's so damn easy to record stuff.

"So each channel needs its own LNB. Though the frequencies are very different, think of each LNB as being like a separate Freeview box - different one required for every channel you want to watch....."

Not quite - and one of these days i'm going to learn how to use the Quote feature on thus forum ---

You don't have an LNB for each channel. That would be rather a lot. You have two pairs, one for each end of the satellite broadcast band. Each of these pairs has one for horizontally polarized channels and one for vertical. That's four altogether.

On a simple satellite system you can switch a single LNB between horizontal and vertical so you only need two of them. You can also switch a single cable between the two LNBs so now you're down to one cable. This works if you only want to watch one channel.

If you want to watch two at once you have a problem. Your first choice determines which LNB is on the end of the cable and also which way it's polarized. This restricts your choice of second channels to those that use the same combination - about a quarter of the total available. Not even Sky could hope to get away with a stunt like that!

On a different note to Simonpearce. Have you considered DVDRAM? You can start playing back while it's still recording and this would appear to give you the features you want - at least until the disk is full. I read somewhere that the disks can be recorded 10,000 times (or was it 100,000). I definitely saw a Pnansonic DVDRAM recorder in the shops for £199 before Christmas. It does regular dvd- too.
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Is it just me, or is wiring an aerial plate a real pain? You need a good length of cable sticking out so you can fiddle and get it connected to the front plate properly, yet its really stiff and therefore you cant push much of it back into the box on the wall. Mine comes a strange, convoluted route to the back of the box so pulling it back from the outside when screwed down is not an option.
It's not just you. It is a pain. Somehow the coax always wants to come off the edge of the plate so that it'll need a sharp bend to avoid hitting the side of the back box - and coax doesn't take kindly to sharp bends. In a hollow wall you can have the cable coming in through the side of the back box directly in line with the connector but this isn't so easy in a solid wall - and that's a gross understatement!

The best you can do is to have the right length of cable looping round inside the box so that nothing gets kinked when you screw the plate on.
But if you fit either a twin box with a blanking plate along side, or just bring the coax into the top side of the box, rather than the back, this helps enormously. Another advert for oval conduit, and using deeper boxes than the absolute minimum.
regards M.
soo glad the cheap SDS drill does masonary chiseling...

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