All posts by Michael
Below are all of Michael's postings, with the most recent are at the bottom of the page.
Michael: Thanks for your comments, JB. The signal should be much the same to all devices, as it comes from a powered splitter, but there could be differences in the cable quality.
I had seen references to issues at Crystal Palace as far as the BBC mux was concerned, but the last few days it has been "no problems reported". But it retuned itself this morning! Also, I haven't yet found any similar info source on the other four muxes. I think there must have been issues on the whole set.
The simple way to stop the HDD recorder retuning is presumably to unplug it overnight until it is wanted the next day!
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Michael: Thanks. The powered splitter should send a good signal to each room, but we had been using daisy chaining of RF leads without problems, and the problems over the last fortnight were not altered by taking one or other of the recorder and the digibox out of the chain. I also tried the digibox in a different room, feeding the signal via Scart to a digital TV - no difference.
The Toshiba box claims to update st 8am, but it could be lying, and I would not be surprised if it tried to make up for a missed scan.
I agree about not fiddling when things aren't going wrong, but after more than a week and with a disgruntled family I could not leave it for ever! At leaat I've learnt a good deal more.
No problems today, so I'm hoping any messing about has stopped. Perhaps it was work being done before the Olympics.
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Michael: Awful again today. The recorder had decided Crystal Palace was too weak. Even after manually retuning everything in sight, the BBC channels (from Crystal Palace) are poor and Sky News isn't there at all this evening. The digital TV is fine so it must come down to the tuner of the recorder ...
... except this had been fine for some years before the digital switchover and for a couple of months afterwards.
Now, we were sold the digital switchover on the basis that the digital signal would be better once analog was out of the way. Quite clearly at the moment it is worse than pre-switchover. Yet this site says there are no problems (at least on BBC) at Crystal Palace. Have we all been sold a pup? If I have to replace equipment that worked perfectly well pre-changeover because someone somewhere decides to weaken the signal for a couple of weeks when they feel like it, who do I sue?
Well, OK, not sue perhaps (and I'm not going to panic buy) but someone must be responsible for this mess. Are they even aware there is a problem, and who do we contatc to complain about what to my mind is a breach of trust on the digital switchover?
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M
Crystal Palace (Greater London, England) Full Freeview transmitWednesday 1 August 2012 12:12AM
London
Michael: Chris's point had also occurred to me. I know red button services have been amended but if the standard signal has been degraded, that's been kept quiet. I can't think of anything more likely to hack off Londoners than making it difficult for loads of us to view what our extra council tax is paying for (yes, I know general taxation funds a lot of it too).
Yes, the digital TV is Freeview too. I have moved that to the location of the HD recorder and it performs fine .. unless of course I feed it the signal from the HD recorder! Similarly, I moved our stone age Freeview box upstairs to the location of the digital TV. Didn't change its performance.
I think the difference has to be the quality of the tuner. The digital TV seems able to cope with lower signal quality and - perhaps just as importantly - substantial variation in signal quality that we are experiencing. Typically, the signal strength is solid at 70-75% but the quality is either down at 30-40% or constantly shifting sharply within the range 10 to 70%. The exception is when the box decides it fancies Heathfield or Bluebell Hill for BBC and/or ITV, when signal strength also drops to 40-50%.
One last point is that some of the similar complaints from people in other parts of London have come when our signal is OK.
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M
Crystal Palace (Greater London, England) Full Freeview transmitSaturday 4 August 2012 11:40PM
London
Michael: We have usually ended up deleting all channels on our HDD recorder (by retuning with the aerial disconnected) and then manual tuning the five multiplexes we are supposed to get from Crystal Palace. This usually gets back the BBC and ITV muxes but does not improve the other three - however deleting everything first does semms to prevent channels being numbered 800+.
It looks as if the Crystal Palace signal is weak at 8am when our HDD recorder auto retunes, so you may have to pick your time.
Even so, tonight's Olympic joy was slightly diluted by watching pixellated atheletes, even on the BBC signal from Crystal Palace. I expect they will get well pixellated in the next few hours though...
A first yesterday was to find one of the muxes claiming to be 698KHz, which appears to be "Waltham" - is that Walthamstow North? Previous "wrong""ansmitters have been Bluebell Hill and Heathfield.
I want to know whom I should be complaining to. The whole thing seems to be secretive and accountable to nobody.
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M
Crystal Palace (Greater London, England) Full Freeview transmitSunday 19 August 2012 11:49AM
London
My digibox and HD recorder are still messing around. Tne Toshiba HD recorder retuned itself to a different transmitter this morning.
Main development: I took the digibox to my father's house half a mile away, where reception used to be worse pre-switchover, and where he used a loft aerial. Sure enough, signal strength on the digibox was about 49%. but signal quality was rock solid at 98%, pretty consistently over the muxes. I checked by phone that the HD recorder was still playing up at home at the same time.
This contrasts with the same digibox at out house showing signal strength of 85-90% and signal quality varying (and I mean varying, as you watch it) of 70-85% on UHF Ch 23 and 26 and 45-65% on the others. The corresponding readings on the HD recorder are 70-75% strength and 48-63% and 25-60% quality. These readings are for when there is a problem. When there isn't (typically in the afternoons) quality is consistent at around 75 or 70%.
So, it's not the digibox (or presumably the recorder) gone wrong. It is the signal quality, or the variation in the signal quality. The digital TV can cope with this but the digibox and recorder cannot.
I intend to do the same test next door when the neighbours are back, which should indicate whether it is the signal coming into the aerial or something between aerial and equipment. That "something" might be a powered signal splitter (and presumably amplifier) in the loft, given that could simply be amplifying errors, but the same setup has been working fine for years, and for several months post-switchover. And the signal strength reported by the HD recorder (and the digibox?) does not seem excessive on the face of it. I'm reluctant to mess around when I still think the incoming signal may be at fault, to the extent that the HD recorder thinks a dodgy signal from elsehwere is better. I have already had engineers round checking that the signal coming from the aerial is OK. They reported that it was fine at around 70% BUT when they came the setup seemed to be behaving I don't know for sure that they also looked at signal quality.
I was surprised that everything functioned with only 49% signal strength but I was even more surprised at the very high signal quality. What should I expect for quality? Should it work on a nice consistent 70% quality, say?
I have a horrible feeling that the answer to this one is "it depends", but would my Toshiba recorder base its retuning decision on strength, quality or a mixture of both?
Annoyingly, none of the televisions we have appear to indicate strength and quality separately, simply giving an overall measure.
The only other possibility I can think of which is unrelated to what is emerging from Crystal Palace, is the Shard. I dismissed this in my mind as the building was essentially there for some time before its opening a few weeks back, but is it possible that some cladding was added late in the day? I know that a small area of Ponders End had issues with Canary Wharf, for example, so a very localised effect is not impossible.
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M
Crystal Palace (Greater London, England) Full Freeview transmitMonday 20 August 2012 11:13AM
London
Michael: To add to my last night's post, I found the HD recorder getting BBC1 etc off 698K this morning. After wiping all chanells as usual, for a change I let it do an auto retune. I found that while it did pick up Ch23 successfully it then went on to pick up the same mux on other UHF channels, evidently overwriting the Ch23-generated ones (i e not storing them as 801+). This was despite the Crystal Palace signal being stronger and of higher quality than the alternatives. However, it does dispose of the theory that Crystal Palace must somehow be next to non-existent at 8am. Hard to know why the HD recorder is doing this. But if the signal as received by the tuner was as it was six weeks ago, presumably it would not be!
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M
Crystal Palace (Greater London, England) Full Freeview transmitTuesday 21 August 2012 11:42AM
London
Michael: Peter - I am probably wrong but I have a suspicion that the "new services" detected may be the same old services coming from a different transmitter.
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M
Crystal Palace (Greater London, England) Full Freeview transmitThursday 30 August 2012 2:48PM
London
Michael: Finally tried our digibox next door. Same result as at my father's house - reduced signal strength, steady 98% quality, fine picture.
So we have:
- digital TVs that work fine on our signal;
- a digibox and a HD recorder which do not work on our signal, producing a lot of pixellation and breakup, but the digibox does work next door and (in a dip) at my father's house. I haven't moved the HD recorder but I am assuming it would also work elsewhere;
- one older digital TV (not mentioned before) which is a bit iffy;
- results similar whichever TV points I use, and whatever configurations of equipment and cabling I use.
- it was worse in mornings and evenings, but more recently yhe problem seems to there all day.
- an aerial engineer confirmed some weeks a go that the signal as received at the TV point was OK, but (a) I'm not sure he looked at quality as wella s strength and (b) it was behaving when they called.
So it appears that the digibox, HD recorder and (to some extent) older digital TV cannot cope with the low (and highly variable) signal quality, but the newer digital TVs can.
There are four TV points in the house, fed from a rooftop aerial with a distribution amplifier/splitter in the loft. As far as I know there is no masthead amplifier (not sure how I can tell, though).
If I switch off the amplifier, the signal goes, as I would expect. So to test if it is the problem I would have to mess around up in the loft playing around with what I have found in the past to be rather awkward connections.
With this setup, is it possible that I could have too much signal strength, and that quality problems not apparent next door are being amplified into something which is upsetting half my equipment?
Is there anything else I can try?
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Saturday 21 July 2012 9:30PM
London
We are having problems with Freeview. The postcode (starting N14) should be picking up Crystal Palace signals. Our digital TVs do this, though the older one sometimes shows pixellation on all but main BBC and ITV muxes.
Our main TV is analogue so has to be fed by either out Toshiba RDXV59DTJB2 HDD recorder or our (very) old Sagem Freeview box. Both were working fine until about two weeks ago. Then the picture on the three non-BBC/ITV muxes started to pixellate, and often became unviewable. I know that the digital TV picture was fine. I also know that if the digital TV gets its picture fed by the Freeview box (I haven't shifted the recorder) it shows the same problems. So it is not the TV. Nor is it the cables, as I have swapped them round several times.
Judging from the signal strength and quality indicators on the HDD recorder, the strength is OK but the quality jumps about. Aerial engineers have also confirmed that the strength (through a roof aerial) is fine. I've considered the weather and wet leaves as possible problems - but the digital TV copes fine. Can't be the Shard, surely!
Is it plausible that the recorder and Freeview boxes are unable to cope with quality variations that are no problem to the TV?
We then started having occasional problems on the BBC and ITV muxes. To my astonishment I found that on the HDD recorder, channels were sometimes displayed as coming from Bluebell Hill or Heathfield, which of course use different UHF channels. I was vaguely aware that other sources were being scanned during an automatic retune, but they had never "got in the way" before.
I got rid of these by retuning with the aerial disconnected and then manually tuning in just the five Crystal Palace UHF channels.
Then this morning, BBC1 was shown as Crystal Palace and BBC2 and other BBC mux channels from elsewhere! Same MUX, different source! How is this mixture possible?
As I had not tuned in any other sources, it seemed that the HDD recorder was retuning itself automatically. Sure enough, in the manual, a reference to a "Service Update" function which searches for newly available channels at 8.00 (am, I presume). No indication of how to switch the function off!
That would explain how the unwanted sources got back, but not why the recorder should choose a more distant (and definitely inferior) source - unless the Crystal Palace source had been particularly poor at 8am (and then only for parts of a mux?).
The Sagem Freeview box is less useful for diagnosis as it shows less info about channels. Also, no manual retune capability.
As fas as I am aware only the BBC and ITV muxes have ever been picked up from anywere other than Crystal Palace, so the pixellation problems on those arise from the Palace signal itself, or at least from the processing of that signal.
So ... does any of this make sense? Has the Crystal Palace signal generally been weakened over the last two weeks, in particular at 8am when the Toshiba scans for signs of life? And, while we should not have to worry about it, how do I stop the HDD recorder retuning itself?