All posts by Tim
Below are all of Tim's postings, with the most recent are at the bottom of the page.
Post I sent recently seems to have been lost, so here we go again.
Mike - we have a booster in the attic because there are about 5 TV sockets in the house and I thought it made sense to do the splits this way. However, as it turns out, there is usually only 1 TV turned on at any one time.
Mux2 signal strength drops below 30 and teh bit error rate climbs drastically when we lose signal - as you would expect. The other Muxs' are all sitting rock steady at between 70 and 75 signal strength with 0 BER. So there has got to be something either wrong with the transmitter or interfering with the Mux2 signal. If it was interference, I would expect another Mux nearest in frequency to Mux 2 to be affected as well (unless the interfering signal is very narrow band - which I would have expected if it was a washing machine or central heating pump - they would be fairly broadband). Mobile phone, OK, would agree, but are there mobile wavelenths operating around 650 MHz? If so, that would appear to be a "design" fault on someone's part. So, still a mystery. But thanks again for the replies.
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Ooops. Should read.... (unless the interfering signal is very narrow band - which I would NOT have expected if it was a washing machine or central heating pump - they would be fairly broadband).
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Mike, forgot to answer your question. Signals all coming from Blackhill - frequencies match. Interference seems to last between 10 to 60 minutes when it does happen.
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Hi. I'm in line of sight to the Rosneath transmitter, which is across the Clyde Estuary. Aerial on the roof. Not too sure how many splits are in the feed as we are in a block of 10 flats and there are 3 aerials on the roof. We have 4 aerial sockets in the flat, and I have been assured that there is a splitter/booster which splits our signal into these 4. On our main TV, I can receive most Freeview channels, apart from C54 and C60. These latter two have a signal strength of about 40-50% but a bit error rate of 2000+ making the picture unwatchable. Other channels have 45-75% strength and 0 bit error rate with a good picture. I've checked for interference (washing machine, fridge, central heating etc) but nothing seems to affect the results. The TV in the bedroom can pick up C60 no problem but as it isn't HD can't receive C54. Any thoughts?
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jb38:
Thanks for the response. Yes, I have already done this and the main TV, when connected to the aerial socket in the bedroom, picks up both missing multiplexes and the signal is good. However, one slight complication is that the Sony DVD/HD recorder is connected to the same aerial socket as the main TV and it can pick up channel 60 OK (is isn't HD so it can't pick up HD channels). The aerial lead used to go into the back of the DVD/HD recorder and then out to the TV. I've tried the TV connected directly to the aerial socket (disconnecting the DVD/HD recorder completely), but this doesn't make any difference. I've now got an unpowered splitter with a 1000 MHz filter in the socket feeding the DVD/HD and TV separately. I didn't use a powered one as this would probably amplify the bad signal. The DVD/HD player still picks up Channel 60, but the TV still doesn't - or at least the picture is awful. Any other thoughts?
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jb38:
Many thanks for the suggestions. The main TV is a Samsung UE40C8000 (why they can't choose easier model numbers I don't know). It doesn't say that it has an on-board booster, so I'm assuming that it doesn't. As we can see the transmitter from the window in the lounge, I had thought about buying an indoor aerial to check that the current aerial feed into the lounge socket wasn't the cause of the problem. Will probably do that now. Amazon offer one with a detachable booster at a reasonable price. I think the walls have insulation inside which has an aluminium foil backing, so this may muck up the signal through the wall - siting the indoor aerial on the window ledge won't pass internal approval! But as a temp measure, should be OK. Thanks again.
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jb38 and Mike B
Thanks for all your advice, most appreciated. I found a powered signal booster in my box of stuff (don't ask) and connected this before I started to spend more money! To my surprise, when I retuned the Samsung, it found both missing multiplexes. Signal strength on these is now >70% and the BER on the HD multiplex is hovering around 50, so much less than the 2000+ it was before. Both multiplexes have a good picture. Early days yet, but fingers crossed. It must be as you said that the Samsung is a bit more delicate than the Sony in regards signal strength. I can only assume that the high BER was due to the Samsung trying to latch onto what it thought was a weak signal. To copy a song title from the Carpenters, it is good to get "Yesterday once more". Thanks again.
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Thursday 27 October 2011 4:25PM
Kilmacolm
Hi. We get intermittent interference on Mux2 channels, but no others. This lasts up to an hour, making the channels unwatchable, and happens at random times during the day. It is not associated with any of our electrical goods being on or off. Aerial is on the roof and we have a booster in the attic. Blackhill is our transmitter. Any thoughts? If your suggestion is that it is interference from external sources, then bring back analogue!