All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.
Sean: translating those frequencies into channel numbers (subtract 474, divide by 8, add 21):
22+ => 37
25 => 30-
46 => 24
Rowridge doesn't yet use C22 or C25, it's probable that whatever data you used to update the HTPC has the final configuration, not the current interim one. C30- and C37 are the correct current frequencies for those services. These will change to C22+ and C25 (plus ArqB moving from C33+ to C28) on 18 April.
C46 could possibly be Brading on the Isle of Wight, though that would be PSB2/D3&4 (broadcast from Rowridge on C24) not PSB1/BBC A which broadcasts from Rowridge on C27. The nearest transmitters using C46 for BBC A are Till Valley and Winterbourne Stickland - the latter is more likely. It's probably just a freak occurrence due to the weather. You are practically guaranteed to get some overlaps at different times of the year.
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Big Mart: The Freeview Engineering Channel isn't really a channel. It's a data stream carrying software updates for various Freeview TVs, set-top boxes and PVRs. It's not allocated a channel number, it's just attached to 105 BBC Red Button, itself not really a channel in any traditional sense, although it can be selected from the EPG or by typing the channel number in.
The list of updates being broadcast can always be found at Freeview and Freesat set-top box updates | ukfree.tv - independent free digital TV advice or DTG :: DTT Receiver Downloads .
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Paul Quinn: At that location, the most likely transmitter is Mendip (BBC Points West, ITV1 West Country Tonight). Other possibilities are Oxford (BBC Oxford News, ITV1 Meridian Tonight), Rowridge (BBC South Today, ITV1 Meridian) or the Corsham relay. Corsham transmits the same programmes as Mendip, but only carries the three PSB multiplexes.
My guess is that the aerial points to Corsham, in which case you should have it moved to point to Mendip. It might be necessary to change the aerial for one of a different group, or a wideband.
If the aerial does point to Mendip, or those are the transmissions the box has stored, you would have had to retune last Wednesday when some services changed frequencies. This is always an opportunity for the naive tuning algorithm to store the wrong services, particularly in high-pressure conditions like we had last week (signals travel further in those conditions, meaning a distant unwanted transmitter can be stored rather than the desired one). The power level of two of the multiplexes was also increased, which could possibly mean the input level is now too high if it was pretty close before.
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Andy Lewis: So far, analogue channels 1-4 have been switched off, but all digital multiplexes are still on. I'm expecting them to go in the next 15-25 minutes. Don't retune until after 6am as the services may come and go between now and then.
BBC Two analogue will never be coming back. ITV1 analogue will appear on BBC Two's old frequency, so if you don't retune your analogue TV, select 2 to watch ITV1, rather than 3. But you should get used to watching through your digital tuner now, as the rest of the analogues go for good in two weeks' time.
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Andy Lewis: Mux 1 (BBC digital channels) now gone. BBC One and Channel 4 analogue are back on, as is ITV1 on C33. They may still come and go until 6am.
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Chris Hylton: It should be possible to set up the cable box to letterbox the picture rather than cut off the sides, but of course you'll have black bars top and bottom.
The BBC's standard has been 14:9-safe for many years - it's a compromise between 4:3 and 16:9 widescreen which has smaller black bars, top and bottom on a traditional screen and at the sides on a widescreen. They actually broadcast like this on analogue - check whether your TV is set to 'zoom' this picture. On digital, they broadcast 16:9 but all captions are supposed to be within the 14:9 area (i.e. nothing within the areas cut off for the analogue broadcast).
Over time, it's likely that they'll migrate to using the full 16:9 screen, so a widescreen would be a good upgrade at some point.
Analogue is switched off starting from the early hours of 12 September. If you need a backup to your cable box, you'll need to get a Freeview box. I'd recommend getting a Freeview HD box now even before upgrading the TV to HD. You may also find that there are channels available for free on Freeview which have to be purchased on cable.
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Tony: This is all governed by trying not to interfere with the Guildford transmitter. The old digital aerials at Hannington only fire to the west, north and south (actually a little to the west of north and south), because most of the digital services were assigned the same channel as a Guildford analogue service and therefore would destroy Guildford analogue, for some viewers, if allowed to fire to the east.
All the COMs are broadcasting at a maximum 25 kW in some direction. Just not your direction.
Last night, as part of the first part of switchover, Guildford low-power Mux 1 was switched off. This allowed low-power Mux 2, previously on C44, to move to Mux 1's old channel C49, to clear C44 for Hannington's use. C44 at Hannington is ArqA - this transmission has now moved to the omnidirectional antenna at the top of the mast, so you should now be able to receive it.
The assignment of which service got which frequency did change a few times over the years - but it's definitely ArqA on C44, not SDN, which remains (with ArqB) on the restricted antenna until 18 April.
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dean: If you mean the occasional prompts reminding you that you need to retune on 4 and 18 April, they come from the broadcasters and cannot be removed except by pressing the yellow key on your remote. They are generated using the same technique that produces the 'Press [red]' indicator during BBC news bulletins, or the similar indicators during programmes that have associated interactive content or audio-selection options (such as selecting different commentaries during live sport).
The only way to really disable these prompts is if your TV has a way to disable the MHEG5 interpreter completely. A few set-top boxes and PVRs have this. However, if you disable it, all interactive content including BBC Red Button will be disabled, as will the popup messages you normally get if you change to a channel that isn't currently broadcasting.
The similar messages on analogue are baked into the picture and can't be removed.
If your box itself is generating a message saying it needs to be retuned even after you've already done so, usually the best option is to do a complete reset, which is recommended at switchover anyway. Look for 'first time installation', 'factory reset', 'full retune', 'virgin mode' or 'default setting' options. Make a note of any 'preferences' or 'settings' values first in case these are reset.
Some people have reported problems if the TV or box can tune in more than one transmitter: see the Digital Region Overlap article for information on dealing with this. You may have to unplug the aerial from the TV, do the full reset, then manually tune only the wanted services, or plug in or unplug the aerial at an appropriate point during the scan.
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Rob R: The Whitehawk Hill transmitter is just south of the racecourse, to the east of Whitehawkhill Road, so yes, probably they are using Whitehawk Hill.
The frequencies you gave match Brighton Central. If you couldn't get Freeview before then the aerial probably is the wrong group and facing the wrong way, as the signals from Whitehawk Hill should have been strong enough, given that the power was at least 10x what Brighton Central now broadcasts!
If you're using a communal aerial, you may find that only selected channels are amplified for distribution. That may be why the signals from Whitehawk Hill aren't being picked up. You'd have to talk to your landlord or agent about getting the aerial moved to point to Whitehawk Hill and the filters retuned.
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Tuesday 3 April 2012 12:09PM
david: If the icons on channel numbers 3 and 4 indicating HD programmes don't appear, that's a data feed problem or a problem with your box. Salisbury is line-fed from Rowridge, and has been since 1998, so is broadcasting exactly the same data that Rowridge is - except for COM4 and COM5 as those are yet to reach their final modes at Rowridge. ITV1 and Channel 4 in SD, and their +1s, are all carried on PSB2, and the HD services are both on PSB3. Both multiplexes are at their final configurations at Rowridge already.
The feed is definitely shown as line-fed in Digital UK's final installer newsletter for the Rowridge group: http://www.digitaluk.co.u….pdf
Salisbury was fed off-air for analogue, and perhaps this could still be used as a back-up if the line feeds fail - though I've read that each line-fed transmitter has two independent feeds from the two nearest telephone exchanges, and the BBC multiplexes (PSB1 and PSB3) can also be recreated from a satellite transmission if both lines fail. It would be interesting to see if vertically-polarized receiving antennas have been fitted, as has happened at most of Rowridge's other relays.