All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.
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Sandy Heath (Central Bedfordshire, England) Full Freeview transTuesday 22 February 2011 12:47PM
Reading
chris davies: losing Mux B would indicate the beginnings of a cable or aerial problem, as higher frequencies travel less well.
I'm not aware of any retuning events at other sites that could have affected reception of Mux B. There don't appear to have been any weather conditions that would cause signals to travel further than normal.
To be honest, I'd wait for switchover, which happens in about a month, and see how it works after that. Note that Multiplex D will move to C67 at switchover, with the same power level as Mux B now has, and will stay there until September. However, it will be using a different mode that requires about twice as much power for the same coverage area.
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mark hawes: if you know how far you are from the transmitter, and the channel numbers, you can use Field Strength Calculator to get an estimate of the likely signal levels.
Looking at the manual for that device (http://download.horizonhge.com/pdfs/HD-TM_USB_Plus.pdf) I can't see that it's necessary to select the mode used.
You should try to get the maximum MER (Modulation Error Ratio) without going over 65 dBuV level. This is an indicator of the signal-to-noise ratio. (RG47SH)
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Sutton Coldfield (Birmingham, England) Full Freeview transmitteWednesday 23 February 2011 12:16PM
Reading
StevenB: Digital UK's predictor reckons you should get as good a signal on the HD multiplex as you do from Mux B (e.g. CBeebies, BBC Four). However, it shows that a change elsewhere will pretty much wipe this out some time in April.
Emley Moor is too far away and on the wrong side of a couple of large hills.
If you're not getting the HD service now, it's probably because your aerial is an older B-type that doesn't have much response below C38. Do you get reliable analogue C5 from Lichfield, of the same quality as the other four analogue channels?
After switchover, the HD service from Sutton Coldfield will use the same channel that BBC Two (analogue) uses now.
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Steven: Free*view* requires an aerial rather than a dish. Since you already have a dish, you could consider Free*sat*, which would be a drop-in replacement for the Sky+ box. However, the channel line-up is a bit different to Freeview: see the comparison at https://ukfree.tv/allchannels.php .
If you want Freeview, through an aerial, it depends on your location. If you provide a postcode we can look into it. (RG47SH)
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JB: a loft aerial is unlikely to give the best results, but it may be possible to set it up for reasonable results as the signals from Sandy Heath will be reasonably strong after switchover.
See http://www.wrightsaerials.tv/articles/whatsat-201007.pdf for some advice on siting and setting up the aerial.
To get all the multiplexes, you would need a wideband aerial, which won't perform well at the low frequencies used by the public service multiplexes. If you really want to keep a loft aerial you may have to use a Group A aerial and forego the commercial multiplexes - but if you can get those channels through Sky anyway, that may not be a problem.
If you've never set up for Freeview before, your loft aerial is probably a Group A already. It won't pick up anything until switchover because the Freeview signals are at higher frequencies than this. It might be best to just wait until switchover completes, in about six weeks, and then see. (RG47SH)
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AlexG: it takes a while for the new aerial to be commissioned. At Oxford it took three months (and then caught fire in the last stage of commissioning, destroying the aerial - hopefully lessons have been learned from this). Analogue signals from Dover will continue to come from the reserve aerial for a while yet.
Malcolm: power may need to be reduced from time to time while men are working on the mast. However, it's unlikely to be the cause of your problem.
You might find that you have another copy of the channels in the 800 range, because Dover transmits most of them on two different frequencies - the others are sometimes called 'Dover B'. If you have an old 'grouped' aerial, the higher frequencies may work better for you. Many TVs simply store the first signals they find, even if they're weaker/poorer quality than signals further up the dial.
Loft aerials don't work as well as roof aerials.
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The new Freeview prediction system - includes Freeview HD | UK Wednesday 23 February 2011 6:38PM
Reading
chris graves: good now, very good after switchover. See the 'Digital UK tradeview' link next to your post, or in the top-right corner.
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John: basically it looks like ITV have only invested in enough delay boxes to manage the six satellite services, rather than all 12 traditional regional licences that they own (and the micro-regions that make up those larger regions). All the transmitters in Wales, the West and South-West (former Westcountry region) are transmitting the Wales +1 service.
ITV are really more concerned with ensuring that the right adverts are played out: it's possible to buy space on all of Wales, the West and South-West as a single macro region.
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Jordy, Briantist: don't forget we still have to free up channels 61 and 62, which will mean another round of retuning for a large number of sites. Ofcom are now calling this the DTT Clearance Programme in their latest variations of the multiplex licences.
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Thursday 17 February 2011 8:23PM
david: for switchover, Salisbury remains part of the Rowridge transmitter group: Digital UK - Rowridge -
However, Digital UK's trade view *is* showing an 'Existing DTT Power-up' event on 28 September 2011. Postcode Checker - Trade View - No details of exactly what's happening are yet available. (RG47SH)