What's going on with my new house's satellite dish/connection?
July 25, 2020 9:26 AM   Subscribe

We're in the UK and we've recently moved to a new house. There's a satellite dish, which leads to twin satellite cables coming out of the skirting board in the living room. When I connect either one to my TV, I don't get the channels I expect to. Why not?

After a bit of googling, it's my understanding that the reason there's twin cables coming out is for a set-top box to be able to show a broadcast and record a different broadcast at the same time. We don't have a set-top box and we don't need that functionality. I tried connecting each directly to the TV individually before I'd googled that, though, and the TV picked up a different (but overlapping) selection of channels on each. What's going on there? There's only one dish - surely they should be carrying the same signal?

Additionally, neither of them picked up the Freesat channels, which is what I really want. They both mainly picked up scrambled premium Sky channels, and even then not as many as I would expect for a satellite connection (only about 80 each time, where I would have expected maybe twice as many). Again, after some googling it looks like Sky uses the same satellite that the Freesat channels are on, so I don't understand why those aren't being picked up. The dish doesn't have any branding on it, but by my non-expert reckoning it's pointing in about the right direction for Astra 2E. We did previously have the same TV directly hooked up to a satellite connection in our old flat, and it picked up all the channels we expected it to, so it doesn't seem like the TV itself is the problem.

Have I understood the elements of this setup correctly? Why am I getting some channels, but not the Freesat channels? Can I fix that, and if so, how?
posted by spielzebub to Technology (6 answers total) 1 user marked this as a favorite
My first thought was "old dish?", and forum posts suggest something along those lines: it may be dedicated to Sky Q which has an LNB -- the thingy that the dish reflects signals on to -- that won't get Freesat channels. You can swap out the LNB -- look for a Quad LNB or Hybrid LNB, ideally one that comes with an adapter kit.
posted by holgate at 9:53 AM on July 25, 2020 [1 favorite]

Or: you may already have some kind of hybrid LNB with different outputs for different signals. This may require using binoculars or getting up on a ladder to see how many coax connectors are on the LNB.
posted by holgate at 9:58 AM on July 25, 2020

I think as this is a UK-centric question you're more likely to find the answer on AV Forum, which is a specialist UK forum for all things TV, Satellite, Cable, Video, Hifi, etc.
posted by essexjan at 11:49 AM on July 25, 2020 [2 favorites]

I'm not sure if British sat-tv is anything like American systems, but I also moved into a house with a dish (probably 1990s vintage), and it led to two runs of coax as well. I don't believe it's necessarily to play/record at the same time; this dish was old enough that I think it predates DVRs as a common thing. I have two theories as to why it has two runs of coax.

Theory 1: the number of channels coming down off the dish is such that it takes two runs of coax to transmit them all, each run of coax only having so much bandwidth. The dish has two Low Noise Block amplifiers (just called "LNBs") and each one feeds a separate run of coax, meaning some signals are on one, some are on the other, and the intent was they'd run into a set-top box that would let you flip through all of them and only send a single (baseband) video signal to the connected TV, hiding the complexity. Apparently this is a common setup in Europe, where one LNB receives from 19.2°E and the other from 13°E.

Theory 2: some small-dish systems had integrated antennas to receive local broadcast channels, in addition to satellite broadcasts. So one run of coax is coming from the dish's LNB, and the other is probably coming from an amplifier that's connected to an integrated antenna in the edge of the dish. I have seen free-to-air satellite TV STBs that have inputs on the rear for both LNB and "Ant" so this is not totally conjecture (here is a US one on Amazon). This could be the case if the dish only has a single LNB.

My guess in your case is for Theory 1; you have a dual-LNB setup (either aimed at two different satellites or at the same position with different polarizations or something). When you plug either of them into your TV, you are seeing a different range of "free to air" broadcasts, which explains why you see some of the same channels, but probably not exactly the same. (If you saw exactly the same output on both runs of coax, then you could have a single LNB with dual outputs, so that you could have two receivers in your house in two different places.)

If you want to use the dish, you probably should acquire a cheap satellite TV STB. You can get one in the US for under $50 with HDMI out, but I have seen older ones at flea markets and yard sales for a few dollars, as people have switched from satellite to terrestrial/cable /IPTV systems. I'd have to imagine the situation in the UK is similar.

Free-to-air satellite TV watching is sort of a niche hobby, there are people who get very into it, trying to find satellites with interesting unencrypted feeds (particularly the uplink/remote feeds). There are sites with channel guides around; you might be able to compare the channels you're receiving and determine which "bird" and transponder your dish is pointing at.
posted by Kadin2048 at 11:58 AM on July 25, 2020

It looks like holgate guessed it in one - the LNB had Sky branding on it, and I'm guessing that since it only had 2 outputs it was for Sky Q.

I replaced it with this one, for £13.99, which was a bit fiddly - the bracket for the old one didn't really want to come off and required some levering of the clippy bits with a flathead screwdriver - and immediately the TV picked up 400+ channels instead of the paltry 85ish it was getting before. Both the new and old brackets allowed for some skew offset adjustment, but the previous one seemed to be set at 0° so I left the new one there as well, which seems to have worked fine.

I also picked up some F type satellite couplers from Wickes to extend the reach of the cables to the TV. Now everything works, in the right place, and I only had to spend £17.50. Thanks to everyone for their help!
posted by spielzebub at 7:44 AM on August 1, 2020 [1 favorite]

Fantastic. Cheap fixes are the best fixes.
posted by holgate at 11:00 PM on August 1, 2020 [1 favorite]

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