All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
Suzanne: Popped into the service depot today whilst on my travels and managed to have a check on your particular model of TV, the result being, that on the "very" limited level of information provided by Bush I cant really say that there was anything I would consider to be of great concern, although I would have preferred to have been able to cross check the chassis with other Brands that use the same chassis.
So for the time being anyway I would exclude your TV as having a problem, especially due to Simon reporting that he couldn't get a signal from Mux Ch59 on another set either, this getting back to the angle that both Simon and yourself are located at from the transmitter, and whether or not the signal radiated is temporarily restricted in a N/NE direction as well as its power being kept low, as its something that rings a bell about having read this somewhere a while back on another technical site, albeit this not seemingly published.
That said though there doesn't seem to be any problems for people residing South of the station.
The result of your check on Mux Ch55 cannot really be classed as good either, as you obviously realise, but to enable proper evaluation of this indication maybe you could report what is it on Mux Ch53 or even Mux Ch60?
Aren't there any neighbours around that you could make an enquiry with as regards to whether or not they can view programmes such as Dave / really / E4+1 / Create and Craft etc? these being on Mux Ch59.
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Tim: Well I suppose my reason for saying that people South Oxford doesn't seem to have any problems is because another person I am presently communicating with in the OX10 area (Wallingford) reported that Mux Ch59 was perfectly OK there.
Your particular code indicates you as 15 miles from the transmitter at a bearing of 9 degrees, and to have any chance of having the channels back in their correct order you will have to carry out a factory reset type of tune.
You could of course use the "edit channels" menu, but that's a long winded process and a reset as described is always the best.
Of course another way that you could do it to avoid the possibility of it going wrong again by picking up low Mux channels from Sandy, (or anywhere else) is to factory reset it WITHOUT the aerial connected, then once complete start an auto-tune whilst watching the scanning progress bar, and when it gets to Ch50 immediately re-connect the aerial and that will allow only Oxford to load.
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Simon / Suzanne:
Simon: Yes thanks, as I would be interested in what any of your neighbours might report.
Suzanne: I will get back to you on your query, as I am a call out engineer this week and have to depart again in a few minutes.
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Tim: The simple way to check what transmitter you are receiving from is by carrying out a signal check whilst you are on a particular channel, and as well as the strength / quality being shown for that channel a multiplex number will also be seen, all you then do is to cross check this number with the Mux numbers used by the station you require, if it doesn't match then it will do on some other station that's shown as a possibility for reception. (obtained via DUK's Post Code reception checker / clicking trade)
Anyone who experiences one or two channels with radically different stability levels compared to the others after a re-tune should always carry out this check, this just to make sure that a Mux from another station hasn't taken up a low EPG position and shoved the one wanted up in the 800 range.
Regarding Mux Ch59, even although I mentioned the other person reporting it as being OK at OX10, I don't however know just exactly how much by, as if a Mux is received at a low signal strength "but stable", it will give exactly the same quality viewing as one that's 100% quality, but I think its obvious that Mux Ch59 on its present temporary low power level is causing great problems for quite a few dependant on the prevailing local conditions.
Regarding your test made with the Toshiba, "if" the aerial you fed into it was exactly the same one as used into the Humax then I am a bit surprised, as Humax boxes have excellent tuners as far as sensitivity is concerned.
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bushistush: Re: clicking on the link, just checked it and it does seem to activate on clicking, but please note that although the usual "click to view enlarged image" option isn't seen it will show as soon as you place the mouse pointer over the picture.
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Mike Dimmick: Although I see what you are getting at, in my opinion "if" an attenuator does solve the problem then I would be looking at it from the point of view that high powered D3&4 (Mux Ch60) is the cause of the problem by its sheer strength being on the verges of swamping the tuner, this having the effect of desensitizing the receiver for adjacent channel reception, which would of course seriously reduce reception possibilities of the low powered ArqA on Mux Ch59.
As you have said, this is one of these odd situations where a main high powered Multiplex is sited adjacent to a lower powered one operating on the same station.
Of course the other downside of adding an attenuator is, that it would also have the affect of slightly reducing the signal strength being received from the already low powered multiplexes, although what might be gained by slightly killing Mux Ch60 could possibly well compensate for any loses the attenuator might make.
Still, it will be interesting to hear what the result is.
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Richard: Not really knowing what method you used to test if an attenuator was required, but if you can get a reasonably viewable signal with only one end of a fly lead connected into the set, then the chances are that an attenuator could well be required if you are using a roof mounted aerial.
Maybe this even applying with a loft one as well, this dependant on location.
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Suzanne: An attenuator placed in line with an aerial socket "will" affect all signals passing through it, and there is no way of avoiding that happening, but in your case the attenuator might take the edge off Mux Ch60's excessive signal strength just enough to allow your TV's tuners sensitivity to rise to a level that will allow Mux Ch59 to be picked up, (hopefully anyway!) although variable attenuators are usually best in these situations as they can be fine tuned (so to say) for best results without killing off the channel you actually want to receive.
I admit to having overlooked the fact of high powered Mux Ch60 possibly coming into the equation, and it was only when Mike Dimmick referred to channel positions that it dawned on me that the whole problem could possibly be caused by tuner desensitizing, and is something I have even referred about to others in the past.
A comment that Tim had made would also back this theory up, that of him being surprised to discover that his Toshiba TV was found to operate OK when his Humax did not, with the likely reason for that being because sensitive tuners are more prone to being desensitized over the lesser types, and the Humax is much more sensitive than the type fitted in his Toshiba, a model that I am acquaint with as far as its receptive qualities are concerned.
High sensitivity tuners are great for being able to pick up a signal in difficult areas where other types are inclined to struggle, but this beneficial aspect of a good tuner turns into a detrimental one in oddball set ups like Oxford, where the powers that be have allowed a multiplex to operate on high power whilst another on the next channel is still operating on low power.
Of course its fully appreciated that people with aerials that's just adequate for reception and no more will not likely have any problems, whereas people that upgraded their aerials when low powered DTT first started very likely will.
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Briantist: Yes, could I also say thanks for updating Oxfords TX power info, as just like Chris.SE I was also aware that you did have this fact mentioned in your "after switchover" notes, but I think that most people checking on power levels possibly didn't notice these qualifications thereby causing confusion.
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Monday 3 October 2011 4:22PM
bushistush: If it still crashes on PSB2 with the indoor aerial in "exactly" the same manner as before then it doesn't look very promising, because as you have said this will be giving a much lower signal to the tuner. The only reason I emphasised "exactly" is because an indoor aerial can make a signal break up even if there is no fault in existence with a TV / box, so this has to be kept in mind during evaluation of results.
Anyway, the sources of these power boards seems to be drying up with exception from suppliers who charge somewhat exorbitant prices for them, so capacitor replacement would be prove to be more cost effective.
On the link you will see a close up picture of the board, but click further to get a blown up view, and the capacitors concerned are C926 and the ones that surround it, although all should really be unsoldered and examined for electrolyte leaks, especially ones in the vicinity of heatsinks.
I don't think that clicking the link will activate it, so copy and paste it into your browser.
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