All posts by Steve Donaldson
Below are all of Steve Donaldson's postings, with the most recent are at the bottom of the page.
Brian Butterworth: When typing a comment with some characters the website drops them when it posts the message. I have found this in the past with the degree symbol (U+00B0). I have to workaround it by writing "deg" instead.
Now I find that the E-with-acute-accent (U00C9) does not render. I wrote "RTE" (with the accent on the E) and it rendered "RT"!
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Chris.SE: It's certainly worth trying a filter to see if it cures the problem. I would have thought that an interfering signal such as mobile would result in lower quality. Fiona, what strength and quality reading does Humax show for the NIMM on C48?
It is difficult to appreciate how it could result in a totally blank screen and no sound on one programme channel carried on the multiplex, while not impacting the others at all. But without exact knowledge as to how it works and therefore whether mobile interference could result in the problem described, I can't be certain. I did describe it as a try it and see sort of thing for this reason.
If fitting a filter does fix the problem then something will have been learned, in that it does appear interference can potentially cause such an effect.
Another thing that has occurred is that the NIMM is DVB-T2. Only one of the main six Freeview multiplexes are DVB-T2, this being PSB3 / BBC B (which carries the HD variants of the five main terrestrial channels).
The main six multiplexes aside, all of the others are specific to a particular area, e.g. those for Local TV, and they are all DVB-T. If I have this right, the NIMM is quite unique in being the only non-main Freeview multiplex to be DVB-T2, particularly as COM7 and COM8 have now gone, which were quasi-national DVB-T2 muxes.
A possible hypothesis, then, could revolve around it being a second DVB-T2 multiplex. During the scan it will be picked up last, and therefore after PSB3 was found. This is a reason why it would be interesting to see if tuning in only the NIMM resolves the issue.
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I would like to make a correction to the immediate prior post: "The main six multiplexes aside, all of the others are specific to a particular area, e.g. those for Local TV, and I believe they are all DVB-T."
I think the non-main muxes (except the NIMM) are DVB-T, but I'm not totally certain.
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Just this morning I have received a notification on AV Forums of the thread on the Sony HXD and some Pioneer receivers stuck on "Update" yet again:
Sony 870 (and all Sony HXD and some Pioneers) DVD Recorders - No Freeview | Page 35 | AVForums
These receivers are quite old but are still used. An error in the data stream (such as by one of the broadcasters) can result in them locking up and it's happened yet again this morning, judging by the stream of users who have posted today.
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Carol Oliver: This is an independent site, not connected with any broadcaster. I don't know what the regulations are with respect to aircraft warning lights, in terms of what ambient light level they should come on at.
As you can see the mast you are presumably familiar with what sort of light level they normally come on at, and the reason you have posted here is because they are coming on later. If you have noticed a change then I suggest you report it to the Civil Aviation Authority (CAA) as I would imagine they would have to take such a report seriously.
See the CAA contacts page:
Useful links and contacts for obstacles | Civil Aviation Authority
There is an email address for Airspace Regulation given (no phone number). I suggest you send them an email: arops@caa.co.uk
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js: Users in AV Forums began reporting their Sony/Pioneer recorders stuck on "Update" yet again yesterday morning:
Sony 870 (and all Sony HXD and some Pioneers) DVD Recorders - No Freeview | Page 35 | AVForums
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TIM wardlaw: I think the best course of action to "hopefully" get good reception for COM4-6 is to switch to vertical polarity, this if you haven't already done so. The word "hopefully" is in quotes because with reception issues there is never a guarantee, and that in this instance it would seem reasonable to conclude that the higher-power VP signals may solve the issue.
Looking back at earlier postings, you have spoken on the saga of Rowridge HP versus VP. Since COM7 and COM8 were turned off, there is no longer any HP-only multiplex, with the exception of the Southampton Local TV one, broadcast in the direction of Southampton.
You have previously given your location as New Milton, and the Freeview Detailed Coverage Checker does not even suggest the Southampton Local TV multiplex as a possibility for your postcode, hence why I suggest it is probably and open and shut case for switching to VP where HP is not satisfactory.
Rowridge, uniquely, broadcasts with both horizontal and vertical polarity, having done so since digital switchover in 2012. PSB1-3 are 200kW HP and 200kW VP. COM4-6 are 50kW HP and 200kW VP.
It occurred to me at switchover that Rowridge had effectively become VP, with the HP transmissions more for legacy purposes, to serve those whose aerials had not been reoriented from horizontal. Subsequently, of course, the HP-only multiplexes of COM7, COM8 and Southampton Local TV threw a spanner in the works, creating a dog's dinner whereby some viewers would have faced the choice of switching back to HP, and possibly having to sacrifice good reception on one or multiplexes to benefit on one or more others.
The power of 50kW for COM4-6 is in no way "low", many main transmitters not even reaching such. Being so close to the transmitter as you are, I wonder if the trees in your vicinity in the direction of the transmitter are shadowing the signal for you, hence poor or variable reception.
The most likely reason for the lower power HP COMs at Rowridge is because they are co-channel with the COMs of Stockland Hill and Crystal Palace (both which broadcast only HP). The PSBs of Rowridge with these two transmitters are not co-channel.
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Fiona Beattie: I have some further thoughts and information. As I'm not in the area, I am going by information online.
The Freeview Detailed Coverage Checker which predicts what signals may be received by postcode doesn't seem to show the high-power NI Mux from Black Mountain. I tried several postcodes in Belfast at which I expect that it is possible to receive the signal well and it did not appear once, not even indicating poor reception. I therefore think it has been missed off the Coverage Checker. Thus, that it doesn't appear for your postcode, I can't be sure whether it might or might not be available where you are.
I think the C48 signal you are receiving may be from the Whitehead relay transmitter, not Divis. Whitehead is nearly 90 degrees clockwise from the direction your aerial is pointing, plus it is a vertically-polarised signal. Your aerial is horizontally polarised to suit Divis. If I am right, it may be a wonder you are receiving it at all. The Freeview Coverage Checker suggests reception of C48 from Whitehead may be possible at your postcode. That said, Carnmoney Hill is also on C48, so I wonder if the two are acting in tandem for you (and you are receiving a bit of both). This is just a suspicion. Carnmoney Hill, while also vertically polarised, is obviously anti-clockwise of Whitehead and therefore closer to the front-facing direction of your aerial than Whitehead.
Try manually tuning the NI Mux signal from Black Mountain, which is on C33 (as DVB-T2). As before, clear the tuning memory by doing a tuning scan with the aerial unplugged, then try tuning in just C33. When you manually tune, enter/select the channel number and give it time for the signal strength and quality to settle, particularly if the signal isn't good enough to tune to the channel. If you can tune it in, see if RTE One is watchable or not.
On 4 September 2019 channel changes occurred at various transmitters in Northern Ireland, this to clear UHF channels 49 to 60 of TV (the "700MHz Band"). All transmissions in that range were moved down, all TV now in the 21 to 48 range. At the same time, the NI Mux expanded with a power increase at Black Mountain and extra transmitters. In County Antrim, it launched on C48 at Whitehead (2.4W) and Divis (10W). It is also transmitted on C48 (16W) from Carnmoney Hill, which it did prior to the 700MHz Band Clearance (meaning there was no change there).
The highest-power transmitter for the NI Mux is Black Mountain, and therefore it covers the widest area. It is near Hannahstown, at the south end of the high ground on which the two transmitters sit. With the Divis NI Mux being such low power as 10W, and with the Digital UK Industry Briefing of August 2019 describing it as "parts of Belfast only", I don't think it likely that it is reaching you in Bangor. My guess is that its purpose is to cover the area that Black Mountain doesn't reach, which I guess would be to the north and north east of the Divis transmitter, as the high ground is likely to be casting a shadow for the Black Mountain signal.
Also on 4 September 2019, the Black Mountain transmitter NI Mux changed channel from C39 to C33, with a power increase from 2,000W to 3,000W. Were you able to receive the NI Mux before 4 September 2019? If so, do you know whether it was on C39?
In terms of DVB-T versus DVB-T2, there are two DVB-T2 multiplexes: PSB3, which carries HD channels, BBC One HD etc. (C24 from Divis), and the NI Mux which you have on C48 and is also transmitted from Black Mountain on C33. All other multiplexes are DVB-T.
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Jeni Spyby: Some of the houses, notably 91 to 97 Waterside may find it difficult to impossible because to point to Bluebell Hill may necessitate pointing the aerial through the loftspace of the other adjoining properties. That said, the new Gillingham Test Centre transmitter may be available, although it transmits only the PSB multiplexes. To explain this requires going into more detail.
Bluebell Hill is 8km out on a bearing of 201 degrees. The Gillingham Test Centre is 4km out on a bearing of 168 degrees, and it went into service on 11th July 2019.
The first thing to do is to tune the channels in. Once you have the channels tuned to the transmitters, then don't retune because it won't improve reception for the transmitter(s) the TV is tuned to.
Gillingham Test Centre is a new transmitter which broadcasts the three PSB multiplexes on the same channels as Bluebell Hill. The two transmitters work together and are in time with one another, meaning you may be receiving some signal from both. However, the Test Centre doesn't carry the COM multiplexes, meaning if you get them they may not be as good, as you can only be getting them from Bluebell Hill.
The channel allocations for Bluebell Hill are:
PSB1 - BBC One, BBC Two, etc. - C32
PSB2 - ITV, Channel 4, etc. - C34
PSB3 - BBC One HD and other HD channels - C45
COM4 - QVC, Drama, etc. - C40
COM5 - Sky Arts, Really, etc. - C43
COM6 - Quest, W, etc. - C46
Check that the channels are tuned correctly. For example, the signal strength screen may should "C32" when on BBC One (as above). Use manual tuning to try and add any missing ones.
The Gillingham Test Centre broadcasts the three PSB multiplexes but not the COMs. The channels it transmits on are as per those I've listed. Thus, try to work out whether you are getting good reception on the PSBs but not the COMs. Is it the COMs that are not good? If so then this is probably explained by the fact that they are only coming from Bluebell Hill, and that with the PSBs you have the Gillingham Test Centre as well.
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Thursday 24 August 2023 1:28AM
Fiona Beattie: In the above posting, "RT" is to mean "RTE". I typed the the "E" with an acute accent, as it is written, but this website totally drops the character!