All posts by Mike Dimmick
Below are all of Mike Dimmick's postings, with the most recent are at the bottom of the page.I forgot about the effect that would have, of including the relay transmitters! Perhaps it needs the ability to show them on a map? It'll still get a bit confusing in some areas that are SFN, or where the same frequencies were used over and over in a small area, but at very low power.
It might actually be less useful than I thought, because the PSBs are usually on former analogue channels, and generally the channel spacing was 3 or 4 channels apart. See the '4-Network Clusters' at World Analogue Television Standards and Waveforms was going to suggest allowing a third channel to be selected, but because of the above, it probably won't narrow the selection. Every single one of those results also uses C28.
The non-switched transmitters are appearing first, then the switched. The links to the transmitter pages are also broken: the non-switched transmitters are fine, but the switched are linking to digital switchover date | ukfree.tv - independent free digital TV advice (RG47SH)
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Hertfordshaz:
If the tuner in your TV is Freeview HD capable, and you connect it to the aerial, you should get HD on the TV.
The 'loop through' connections which pass the aerial cable through do one of two things to the signals: either nothing at all*, or add the recorder's output at a selected frequency. The tuner in the TV is responsible for decoding the signals.
* OK, usually there's a small boost to the signal level to make up for the losses inside the recorder, and this usually brings a slight increase in noise as well. If your reception is marginal this can make a difference in how well the TV performs.
A lot of TVs were advertised as 'HD Ready'. This means that they have an HD-resolution screen (at least 720 or 1080 lines), can handle external HD-resolution inputs on component cables and at least one sort of digital input (HDMI or DVI), and do content protection on the digital input. However, the standard for broadcasting HD channels in the UK wasn't finished until late 2009, so if your TV was designed before that, it's unlikely to be able to show HD channels without some help.
Generally, it's a good idea to use an amplified splitter as close to the aerial as possible, if you're going to feed multiple rooms. It sounds like you may have just used unpowered splitters or even just twisted the cables together. For best results you need proper splitters that keep proper continuity all around the centre core and are matched properly to the cables - if you don't 'terminate' a coaxial cable properly, the travelling signal reflects off the end of a cable and you get echoes, which confuse the tuner. (On analogue, you get 'ghost' pictures.) The TV or box normally takes care of this, but it goes wrong if cables are split incorrectly.
Splitting cables always reduces the signal level in the cable. If it drops too much, you need to either use a larger aerial, or add an amplifier. The increase in gain should be just enough to offset the loss through the splitter and the longest run of cable. An amplified splitter will usually have just enough gain to offset its own loss.
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Frank Beckwith: the Digital UK prediction for your postcode shows that the signal level, relative to interference, should be sufficient to receive the ArqA and ArqB multiplexes after September.
Postcode Checker - Trade View (RG47SH)
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doug: I've looked at your location on DigitalUK, and looked up the National Grid Reference with nearby.org.uk, looked at the terrain at Terrain - shows radio profile between two UK sites to optimise you DTT, Freeview, DAB or analogue TV reception and computed the field strength at Field Strength Calculator .
My guess is that you should have more than sufficient signal now to use a small log-periodic aerial. If you're looking at Justin Smith's website at ATV`s Choice Of Aerials for digital TV , I would say that his 'DM Log' (which appears to be a BlakeUK DML26WB) would be sufficient. If you want to play it slightly safer, go for the Log40.
Your problem is that the current digital multiplexes are so low in power compared to the analogue levels - getting the digital levels sufficient usually means that the analogue levels are way over spec. If your gain is too high now, you will have problems with the high-power digital signals. You might need to add an attenuator after switchover if you overdo it now. (RG47SH)
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Tom Latham: your aerial probably points to Sutton Coldfield rather than Waltham. It looks like either will be a good choice for you after switchover. Right now, Sutton Coldfield should provide a slightly more reliable service.
I believe you would get a Birmingham news service on ITV1+1 from Waltham anyway. If you're talking about ITV1+1, check whether ITV1 and BBC One are providing the right service. ITV haven't yet provided a full regional service for ITV1+1, you get the nearest one that they *have* provided.
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mark hawes: the Horizon website has updated data files and firmware for your meter. Go to Horizon HD-TM Plus and click Product Downloads under Resources on the right-hand side for the data files, and 'Upgrades / Utilities / Docs' for the firmware. (RG47SH)
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Debbie Aliaga: Is this a change, or have you only just tried using Freeview?
The Bury St Edmunds transmitter does not yet transmit digital signals. It will start doing so in November. However, Digital UK shows that it won't be your best option - in fact it will be very poor.
Your best option after switchover is the main transmitter at Tacolneston, and is also your best option now.
If you're already using Tacolneston, I'd look for a break in the cable, a damaged aerial, or a major mis-alignment.
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Rhys: you're most likely using the Long Mountain transmitter. This is a 'Freeview Light' transmitter - it only broadcasts the three public service multiplexes.
The commercial multiplex operators declined the option to broadcast from the transmitters they did not broadcast from before switchover. They decided it was too expensive.
You might get a usable PSB signal from The Wrekin, but the predictor reckons the commercial multiplexes will be too weak or there will be too much interference.
You might just get Mux D (Arqiva B after DSO) from Sutton Coldfield, but it will probably break up a lot.
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Ken: you're not actually expected to get anything useful from the Dover transmitter at the moment. The problem is that you don't have line-of-sight to the transmitter, as there are hills in the way, and it's very low power right now.
It should improve next year (probably July, but it hasn't been announced yet), though it will probably never be rock-solid.
All transmissions from the Dover transmitter will be within the previous analogue aerial group. You should not need a wideband, indeed, a wideband will normally perform worse than a grouped aerial with the same number of elements. You need a Group C/D aerial, which will normally be smaller than a wideband with the same number of elements.
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Thursday 10 March 2011 3:42PM
Reading
'Find a Freeview transmitter by frequency' seems to be using pre-switchover frequencies throughout, rather than using the switched frequencies for the transmitters that have switched. For example, selecting C22 and C25 does not find Storeton, while it does find Bristol Kings Weston, which no longer uses those frequencies.