Digital television
Apr. 22nd, 2017 04:58 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
mtbcMostly in the US we had cable television except for a period in rural Ohio when we had satellite television through DirecTV. By the time we were in Rhode Island and Massachusetts we had high-definition cable. On moving to Scotland our house had satellite television from two dishes so I learned about DVB-S2 and figured out from our channel selection at which satellites they pointed. The satellite dish at our present property gets poor reception; there is a shiny antenna in the attic so we instead use the terrestrial television.
I initially bought a cheap Chinese decoder box off eBay to discover if we have usable broadcast signal at all. It turns out that we do; we still use that box to watch live television. Still, its configuration's set of countries does not include the UK and it receives rather few of the official Freeview channel list so I guessed that it is just a bit rubbish. Today I tried plugging an Afatech AF9015 decoder into my laptop's USB and, after providing the required firmware, checked what w_scan could find: it turns out to be even fewer channels though at least those are perfectly watchable through mplayer.
It thus seemed time to learn more about DVB-T2 and Freeview. I learned that there are
A small puzzle is that our box does receive channels from the COM 7 multiplex, also missed by the AF9015. I have no reason to expect those to be relayed from Perth yet we get them somehow.
I initially bought a cheap Chinese decoder box off eBay to discover if we have usable broadcast signal at all. It turns out that we do; we still use that box to watch live television. Still, its configuration's set of countries does not include the UK and it receives rather few of the official Freeview channel list so I guessed that it is just a bit rubbish. Today I tried plugging an Afatech AF9015 decoder into my laptop's USB and, after providing the required firmware, checked what w_scan could find: it turns out to be even fewer channels though at least those are perfectly watchable through mplayer.
It thus seemed time to learn more about DVB-T2 and Freeview. I learned that there are
multiplexesof channels provided by various transmitters. Angus' transmitter provides a rather full service but coverage here is marginal so I expect that our antenna is instead directed toward Perth. The Perth relay, like the Tay Bridge one serving the area near my workplace in Dundee, is listed as providing a limited set of channels from the Angus transmitter: only those from the BBC A, BBC B, D3&4 multiplexes. The AF9015-based decoder misses the high-definition channels provided by BBC B but our cheap decoder box receives them, it is just that some parts of the UK, even cities, are served with but a considerably partial set of the free terrestrial broadcast channels.
A small puzzle is that our box does receive channels from the COM 7 multiplex, also missed by the AF9015. I have no reason to expect those to be relayed from Perth yet we get them somehow.
