Using Satellite Dish for UK Freeview

[mikeisyou]

Hi i live along the south coast and ive been experimenting with my satellite dish to pick up various terrestrial channels, I have only had luck picking up some channels i can already get plus not all frequencies work.

on UHF CH24

46% Signal Quality from Terrestrial Antenna
58% Signal Quality from Satellite Dish

UHF CH26+ do not seem to work

I wonder changing the lnb to ka-band or c-band would help

 

[PaulR]

I'll be honest, I don't really understand what you mean. You can't use a satellite dish and Ku LNB to pick up terrestrial frequencies on UHF Channel 24, 26 or any other. Changing the LNB will make no difference - it still won't work.

You'll have to explain exactly what you mean and why you think you're getting terrestrial TV through your satellite dish. My first thought is that you're picking up the FTA satellite transmissions from Astra 28 which mirror the terrestrial transmissions - perhaps you can confirm?

 

[timo_w2s]

Or the shielding of the satellite cable it being used as an aerial? But I can't imagine that would outperform even the worst proper UHF TV aerial...

 

[mikeisyou]

I'll be honest, I don't really understand what you mean. You can't use a satellite dish and Ku LNB to pick up terrestrial frequencies on UHF Channel 24, 26 or any other. Changing the LNB will make no difference - it still won't work.

You'll have to explain exactly what you mean and why you think you're getting terrestrial TV through your satellite dish. My first thought is that you're picking up the FTA satellite transmissions from Astra 28 which mirror the terrestrial transmissions - perhaps you can confirm?

Dish is pointing at 39e HellasSat i took the coaxial cable out of my satellite receiver and put a aerial connector on the end of it then plugged it into my LG Smart TV and scanned. Astra 28 is Freesat not Freeview although a lot of people do get the 2 mixed up. I did try scanning with my Fibo 1.28m dish which is pointing at nilesat but nothing scanned in. I think my tv aerial is inside (I have 2 aerials but i don't know which is which) which might explain why the dish has outperformed it.

 

[Analoguesat]

!

Interesting experiment, you must be picking up the local uhf signals somewhere. Are the signals strong enough to scan in with no aerial cable attached?

When digital started here in Galashiels I just about managed to get pictures off the Langlee transmitter using 1m of scaffy single core wired poked into the aerial input of the digibox! The transmitter was line of sight half a mile away but I was the wrong side of a steel framed building

The TV & digibox "just happened" to be in my office that morning having been appropriated the previous day!

Ahem

 

[PaulR]

Is it possible that yor satellite feed has a diplexer fitted in the loft to combine a TV aerial with the satellite feed?

Another way would be to have a a box called a multiswitch, which is designed to combine satellite signals with TV signals and then provide outputs to multiple devices such as TVs and satellite boxes. I have such as system installed to pipe the signals around the house. The big giveaway is that you need an LNB with four outputs so you probably don't have that.

Or it could be just as Timo said, you have a leaky cable from the satellite dish.

 

[Hixxy1]

You're probably close enough to a transmitter to pick up a sufficient terrestrial signal radiating into your coax. I've seen it before in new build house that are 30 miles from the transmitter and still receive the stronger multiplexes. The customer couldn't believe it when I explained that he didn't have an aerial connected.

 

[mikeisyou]

You're probably close enough to a transmitter to pick up a sufficient terrestrial signal radiating into your coax. I've seen it before in new build house that are 30 miles from the transmitter and still receive the stronger multiplexes. The customer couldn't believe it when I explained that he didn't have an aerial connected.

I think your right, iam 20.509 away from the Transmitter which is on the Isle of Wight

 

[Hixxy1]

Rowridge is a powerhouse and part of the signal will be travelling across the water without any obstructions.

 

[mikeisyou]

!

Interesting experiment, you must be picking up the local uhf signals somewhere. Are the signals strong enough to scan in with no aerial cable attached?

When digital started here in Galashiels I just about managed to get pictures off the Langlee transmitter using 1m of scaffy single core wired poked into the aerial input of the digibox! The transmitter was line of sight half a mile away but I was the wrong side of a steel framed building

The TV & digibox "just happened" to be in my office that morning having been appropriated the previous day!

Ahem

Interesting stuff

 

[Hixxy1]

I've been close to big transmitters before and the signal can right over the top of you. Also seen tuners being swamped and lots of multipath interference 1/4 of a mile away from crystal palace when it was running 1 megawatt. That made a complete mess of the picture.



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[Topper]

In my previous house that was at the top of a hill some twenty six years ago , I had clear line of sight to Winter Hill and a portable colour TV without any kind of aerial and I could pick up all 5 channels no problem

 

[mickwig]

I know Winter Hill. Used to live just below it.

 

[PaulR]

I suppose that the real question is - Why does the regular aerial give a lower signal quality?

There a number of things that we don't know. What type and group aerial is fitted? Is it actually pointing at Rowridge? Is it aligned for horizontal or vertical (interesting this - see later) polarisation? Is there an amplifier involved anywhere?

The first answer might be that the signal is so strong through the aerial that it's overloading the tuner causing an actual reduction in quality. This is relatively easy to test by putting an attenuator into the lead before it goes into the TV and seeing if the quality then goes up.

Rowridge transmits on Channels 21, 22, 24, 25, 27 and 28. It is a unique main transmitter as it transmits in both horizontal and vertical polarisation - this is to help combat co-channel interference, you align the aerial to the polarity that gives the lowest interference. In V mode all channels are 200KW but in H mode only 21, 24 and 27 are 200KW the other thre are 50KW. These lower powers are so as to minimise inerference with Crystal Palace which also uses these channels. As to why channels 27 and 28 don't come in, perhaps answers to the questions above might help.

I had vaguely remembered about the dual polarity transmitting but I gained most of my information from this very helpful web site http://www.aerialsandtv.com/rowridgetx.html#RowridgeChannels for nerds like me it was a fascinating read.

A final easy test - do you get any channels by putting a short length of wire by itself into the TV aerial socket? (the proverbial bent coat hanger test).

 

[2cvbloke]

I had vaguely remembered about the dual polarity transmitting but I gained most of my information from this very helpful web site http://www.aerialsandtv.com/rowridgetx.html#RowridgeChannels for nerds like me it was a fascinating read.

Using that website, I found out what that twig over at Burnhope is:

http://www.aerialsandtv.com/pontoppiketx.html#BurnhopeTransmitter

I never knew that it was used for TV (now used solely for radio), I thought it was just some radio tower for aviation (there's no real clue as to it's function when you go past it!!), though it does explain why I had to turn my indoor aerial around for C5 when it was analogue (well, that was when they were switching off and I was scanning around for the analogue TV, the rest of the time I used Pontop's digital feeds), cos we're smack bang in the middle of Pontop Pike and Burnhope...

 

[sonnetpete]

When I was a TV engineer in and around Stockton it and Burnhope were the only transmitters we got signals from until they opened Bilsdale. Then you could get a signal on the proverbial piece of wet string....

 

[Lazarus]

Not here you can't! And we're only six miles away from Bilsdale.


Topography.

 

[sonnetpete]

I should have added....'with notable exceptions'....

 

[PaulR]

I found out what that twig over at Burnhope is...
I never knew that it was used for TV (now used solely for radio),

Same situation for us as Holme Moss used to be a Band I TV transmitter for both sides of the Pennines (when Look North on BBC really was north!). WhenBand III was introduced it was briefly considered as a suitable site but separate sites at Winter Hill and Emley Moor were considered better - no doubt due to the slightly different transmission characteristics at the higher VHF frequencies involved.

Now it's "just" a radio transmitter for Band II FM and Band III DAB.

But we're in danger of drifting off topic...

 

[smoggy07]

In my previous house that was at the top of a hill some twenty six years ago , I had clear line of sight to Winter Hill and a portable colour TV without any kind of aerial and I could pick up all 5 channels no problem

How long ago did channel 5 start lol