All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
G.Richards: Caernarfon receives its signal from Arfon which means that if it is off, then your transmitter will be as well.
Refer to:
Digital UK - Planned Engineering Works
There is engineering works at Arfon 0900 to 1700 today.
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Colin Halton: COM6 which carries Film4, Yesterday and others has always been on C54 since switchover. Therefore if you were tuned to a different channel you must have been receiving it from another transmitter.
If the unwanted signals are outside the range of channels used by Bluebell Hill then you may be able to get around it by unplugging the aerial lead for that part of the scan. For example, Crystal Palace's are all in the 20s so unplug the aerial for the first 30% of the scan.
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Pearce Chapman: Yes, the aerial should be vertical for Birch Vale.
If your TV has manual tuning then don't use the automatic tuning. Reorientate your aerial to vertical and do a manual scan of UHF channel 43 for ITV, Channel 4, Channel 5 etc.
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Pearce Chapman: There isn't any likelihood of you getting more channels from a terrestrial transmitter at your location. This is because the Commercial broadcasters pick the most lucrative transmitters to use as they operate purely for profit.
See here:
Londonderry (Northern Ireland) digital TV transmitter | ukfree.tv - 10 years of independent, free digital TV advice
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Wilson Laidlaw: Mains cables are not meant for passing signals over because they are not screened. There is also no filter to ensure that the noise these wretched things generate doesn't get into appliances.
Your house wiring becomes an antenna to distribute the signal far and wide (its effectiveness depending on how well it happens to be designed for the frequencies concerned).
See:
Welcome to Ban Power Line Technology
Consider re-siting your wifi router or running cat 5 cable between rooms. Flat cat 5 leads are available to put under carpets if there is really no other way or you can buy cable protector such as in this example:
Cable Protector
Obviously ideally you shouldn't really stand on the cable, so if you do put it somewhere that it is likely to get trodden on on a regular basis, then it could always need replacing at some point.
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Lynn Steenson: Go to the manual tune function on your receiver and see if it might give you some indication as to the strength and quality of the three COM muxes as they may be sitting just below the strength your receiver needs to show them or they may be above but of too poor a quality.
Once you have the manual tune screen up, select the UHF channel and give it five or 10 seconds. See if it gives an indication of strength and/or quality *before* you press the button to scan the channel. Do this for each of the COMs.
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Lynn Steenson: There is no such thing as a "digital aerial" as set against an "analogue aerial". Aerials work based on frequencies received and those used for TV after switchover are the same as those used before.
If your aerial is a yagi-type, which it is likely to be if it is a "high-gain" one, then it won't be "high" gain on the low (Group A) channels used by Divis if it is a wideband. That said, if it worked prior to switchover, then maybe you aren't too far off; perhaps additional or even less amplication, as suggested by Peter, is the answer.
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Murf: It is so as to be able to record a different channel to the one being viewed.
Unlike with terrestrial (Freeview) where you can have one feed and be watching as many channels as you like using separate receivers, satellite requires one feed per channel being watched.
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Lynn Steenson: The COM strengths would be expected to be the same whether you go through the manual tune screen and enter the UHF channel or (with the services, e.g. Dave, stored) bring up the signal strength screen, so I'm not sure why you got lower readings then. The only thing to say is that you might have to give it a few seconds (10 maybe) to settle.
That said, the strengths being in the mid to high 90s could perhaps be an indication that they are too great, presumably being driven that high due to your amplifier. I suggest that you try reducing the level of amplification so you get around 75% to 80%. It isn't critical; quality is the important thing with digital reception.
If the signals are on the high side, say verging on excessive (for what your tuner can cope with), then that is akin to turning the volume right up to maximum on your hifi. What happens is the sound distorts and quality is lost. The COMs use a signal type that isn't as rugged as the PSBs, which could explain why they are lost and the PSBs aren't - this is my suggested explanation if you find that reducing the level of amplification does the trick.
You may even find that the amp isn't needed at all. You are around 30 miles from the transmitter and I believe that you even reside in the area coloured green in the map above.
You should also be able to combine the feed from the Divis aerial and that of, Monaghan I guess, so you can view both Saorview services and Freeview services on the same/all receivers. For this you will need a diplexer - probably one that splits at C51.
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Wednesday 16 January 2013 4:36PM
GDR Caernarfon: Because they aren't available from all transmitters. See here for an explanation:
Londonderry (Northern Ireland) digital TV transmitter | ukfree.tv - 10 years of independent, free digital TV advice