All posts by Dave Lindsay
Below are all of Dave Lindsay's postings, with the most recent are at the bottom of the page.
Brian Egles: The audio type is wrong and needs setting the same as that of the Sky box. It probably wants changing from BG to I.
See:
World Television Signal Guide by Country
I is what was used in the UK.
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mr v johnston: At the first stage of switchover (10th October), BBC standard definition channels go on full power from pre-switchover transmitters such as Divis and they become available from relays such as Black Mountain for the first time. On 24th October the other digital channels become available.
If your main aerial points to Black Mountain then you probably know that it does not broadcast Freeview now. It will also only carry Public Service Broadcaster (PSB) channels after switchover. These are BBC standard definition TV, BBC high definition TV, BBC radio, UTV, UTV+1, UTVHD, ITV2, Channel 4, Channel 4+1, Channel 4HD, E4, More4 and Channel 5. Existing aerials on Black Mountain are expected to work after switchover as all channels are in the current analogue group.
Those who cannot receive from a full-service transmitter (which amounts to about 8.5% of the population) and rely on a PSB-only relay will only have access to PSB channels.
You refer to a "digital aerial". You must be receiving from another transmitter, presumably Divis. This will carry the full complement of Freeview channels after switchover, so you may wish to retain it for this purpose.
Aerials aren't designed specifically to pick up analogue or digital signals. In some cases different aerials are required due to different channels being used or perhaps lower power (weaker) signals).
Reception of RT/TG4: There is a potential added complication if you would like to receive RT and TG4, if you are in an area where they can be picked up. If you have another aerial pointing to a transmitter located in the Republic, then you should be OK with that.
However, these channels will also be broadcast from three Freeview transmitters in Northern Ireland, this being the "NI Mux".
The NI Mux will be broadcast on high power from Black Mountain rather than Divis. It will be horizontally polarised unlike the other Black Mountain channels which are vertically so. The reason for this is because it is principally intended to serve those who receive from Divis. With the two transmitters being close together, the angle between the two is slow small for those at a distance (e.g. for those in Belfast) that a single horizontally polarised aeial will work for both.
If you are in an area where Black Mountain isn't that far off the bearing for Divis, then the single aerial may work for both. If they are in different directions you may wish to try reception of the NI Mux using the horizontal Divis aerial (even though it faces another direction).
If a different aerial is required for Divis and for the NI Mux from Black Mountain, then your existing Black Mountain aerial should work if you change it to horizontal. You can combine the signals from two aerials using a diplexer (providing the channels used by each transmitter suit this setup):
Online TV Splitters, Amps & Diplexers sales
The NI Mux from Black Mountain will be on C39. Divis' channels will range 21 to 29. There is the potential (if the powers that be so decide) that in the future there will be a multiplex on C36 from Divis and two others in the range 31 to 37. For this reason a diplexer that "splits" at C36 would inhibit reception of that channel. The one that splits at C38 would allow it, but the neighbouring channels C37 and C39 will be attentuated. As the NI Mux from Black Mountain will be much higher power than the vertically polarised PSB channels, this may not be an issue.
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John Humphrey Williams: The Freeview Lite relays aren't likely to be upgraded to provide all services. This is because the Commercial broadcasters (those that don't transmit from these stations) don't wish to pay for them.
The Commercial channels achieve coverage of 90% of the population from 81 of the largest transmitters (largest by viewer population). The other 8.5% of the population that can receive Freeview are served by over 1,000 small relays such as Dolgellau and the cost to the Commercial broadcasters to transmit from these is roughly the same as that for the 81 current transmitters.
Because they operate solely for profit and have no obligation imposed on them to operate in the general interest of the public, they opted not to double their cost of transmission in order to increase their viewer bases by about 10%.
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Mike: No, never.
See my reply to John Humphrey Williams above as he asked the same question of his local relay.
Unfortunately, even if you can receive from Pontop Pike, its COMs (those channels that don't broadcast from Rothbury) are co-channel (same frequencies) as the multiplexes from Rothbury.
So unless you can locate your aerial somewhere where it is screened from the Rothbury signal and where it can receive from Pontop Pike, then you won't receive the COMs.
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Richard Davis: Please answer me this: how long is a piece of string?
It goes on to say "ie when the General Entertainment genre nears full capacity".
In essence, I understand that this means that when the "General Entertainment" genre gets so full that LCN 65 is allocated, then and only then will Childrens' and News channels move. This will take place on the Wednesday that follows 16 weeks after the allocation of LCN 65. There is another qualification above regarding should that date full within a freeze-period on changes.
And so, without knowledge of when LCN 65 might be allocated, it isn't possible to give an absolute date for change of Childrens' and News genres.
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mr v johnston: I've taken a closer look at this.
The Divis coverage map suggests some gaps in the Hannahstown area. If, however, you currently receive analogue from Divis rather than Black Mountain, then your existing aerial would be expected to work for digital after 24th October.
Divis will use Group A channels exclusively, so a Group A aerial will be best, if a yagi type is used. Wideband yagi aerials have less gain on Group A channels which is why they aren't advised. See:
Digital TV Transmitters
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Phil: First off, confirm that BBC One is tuned to UHF channel 44 and not that of another transmitter.
I have made two observations:
1. There is a nearby TETRA base station in or adjacent to the car park which is next to the Adult Community Learning Centre. It is the mast with two vertical antennas on.
This could be the source of interference on one channel.
2. The Digital UK Postcode Checker predicts "no" reception of Sudbury's PSBs (BBC, ITV1, Channel 4, HD etc) whilst "good"/"variable" on its COMs (ITV3, Pick TV, Film4 etc).
Whilst such predictors should always be taken with a pinch of salt as they can in no way be accurate in all circumstances, we can but wonder why that might be.
Rouncefall is a single frequency network with Sudbury's PSBs, meaning that it broadcasts only PSBs and that they are on the same channels as Sudbury, something which the digital system allows.
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Phil: Prior to switchover, BBC Two analogue was on C44. How was its picture? Perhaps if it is interference from the TETRA station, then it would have affected the old analogue signal.
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Phil: If it is interference from the TETRA station, then a filter will probably alleviate the issue.
Search the internet using terms such as <<tetra tvi>> <<tetra dtt interference>>.
(TVI=TV interference, DTT=digital terrestrial television)
See:
TETRA Filtering - Technical Information - Blake UK
Wright's Aerials
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Friday 5 October 2012 10:00PM
Deeptheone: Your postcode resolves to a block of flats. If you are using a shared communal aerial system then this could be caused by a fault with it and it will be down to the party responsible to sort it out.