All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
Jo: And when you say "another complete retune" it should really be from after having carried out a "factory default" procedure which will have guaranteed that nothing is lurking about in the boxes memory system.
The set top aerial is also a good idea, as with you being located at only 3 miles away from the transmitter it would be extremely easy to suffer from signal overloading problems.
| link to this comment |
Ivan Pope: At only approximately 2 miles from the transmitter your aerial should not be anything elaborate or problems can be expected due to an excessively high level of signal being received, as this can block reception in the tuner of whatever you are using by its RF input circuit being swamped thereby causing instability to occur.
For a test try using a set top aerial or a short piece of wire (about 12") connected into the inner cup of the aerial socket on your TV or box, then follow this action by another re-tune.
| link to this comment |
sparky: Just spotted your update on events.
Regarding the settings you see when on the manual tune screen of your box, do not alter anything that's pre-set as far as the bandwidth (or anything else) you see is concerned, as the bandwidth is the standard spacing between channels in the UK system, and therefore any alteration to this will cause confusion in the tuner as you will be bringing artificial offsets into the equation of a far worse nature than already exists in some UK muxes with either plus or minus offsets.
Also, and as touched on in my previous posting, I can tell you that you are not achieving anything with that type of aerial you are using and should discard it in favour of something more in line with what I suggested, as you should appreciate that the debatable higher gain claimed for these type of aerials brings with it the penalty of them being super directional, this meaning than unless they 100% absolutely perfectly razor sharp aligned on the signal then their performance is worse than from a small contract type aerial, as the numerous directors (elements) you see whose whole purpose is to direct the signal towards the active element of the aerial (in front of the reflector) can actually partially block the signal from getting to it if the aerial is the merest fraction off being perfectly aligned, because as well as the directors then acting like partial screens any signal that is directed will be wasted by being focused towards a small part of the active element or even onto the reflector, this defeating the whole object of the design.
| link to this comment |
iain: Unfortunately I haven't, as not only have I enquired at two of the service depots I have contact with, searching for info there only to find that the minimum of service information has been supplied and with none of appropriate to what I was seeking, of course when dealing with TV's that use variants of PCB's manufactured by Vestel (Turkey) this is nothing unusual.
The only thing that did make me wonder was the fact of you stating that it was originally BBC3 that you lost as that's on the main PSB mux, and so if anything had glitched during scanning it would have been corrected with a subsequent full scan after resetting the TV, but now that you have lost all channels then its either a case that the tuner has completely packed in or that the tuner is not capable of dealing with the new transmission modes, as you have verified that the problem is not caused by an excessive level of signal by the test being done with the set top aerial.
I realise that Argos was the main source of this model so it might be of interest to give them a call and "attempt" (debatable if they would tell you) to find out if the problem you have is common knowledge to them.
| link to this comment |
Robert: Could I request that the next time channel Ch62 drops out or indeed any of your other channels, that rather than immediately re-tuning the device in question just carry out a signal / quality level test on the blank screen, as the chances are that the signal will still be there but hovering at a level that's just under the reception threshold of your receiver, which of course results in the blank screen.
The reason I ask is that it would be interesting to know what this level is when compared to normal operation, as for satisfactory reception the "normal" would have to be considerably higher or the picture / audio would suffer from frequent intermittent glitching during the fluctuations in signal levels that occurs throughout a 24 hour period when dealing with any signals received from non line-of-site transmitters at reasonable distances away, in your case Oxford being at 27 miles and with Mendip being at 46 miles, although the latter falls well behind Oxford as far as reception predictions are concerned.
Just out of interest, what brand / model of device is the item in question? and does this particular problem also affect any other devices that might possibly use the same aerial system?
| link to this comment |
David Taylor: The difficulty with your problem is that its been proven as not really being one of an issue concerning reception, but one that on the face of it should be far in a way simpler to rectify, insomuch that when the Freeview box is coupled into the TV using a normal scart lead some form of instability is taking place, or indeed is already in existence within the box itself as you have verified that the scart lead is OK between both devices, and so taking this into account and coupled to the symptoms experienced (especially hum on audio) is still inclined to point to a defect in the Freeview box (or separate power supply to?) albeit this is the second one of that model you have tried. (what model is it?)
By the way the scart pin connections used by the VCR will be less than is used by the Freeview box as the VCR will not normally have an RGB output, so maybe you could check on the TV and also the box that CVBS is selected as the boxes output / TV input "if" it allows you to set this. That said, the only positive way of knowing if the box is actually faulty or not is to connect it into another TV, no aerial connection being required in the box for a test as the problem was still seen with no aerial connected.
| link to this comment |
NICK ADSL UK: Regarding Freeview reception, I have always been of the opinion (and have frequently voiced it) that anyone of a critical nature who demands a virtually trouble free service for 99.9% of the time should always consider Freesat as their No1 choice for reception, as although Freeview reception certainly scores for its sheer versatility as far as being used to feed a number of TV or boxes in the same property is concerned without any great hassle being involved, this when compared to the situation with satellite reception where individual feeds from a dish to each receiver is required, but this latter inconvenience is a small price to pay for super reliable reception, with myself using a combination of Freesat / Freeview / and Sky's free to view services, albeit that roughly 80% of the live viewing made via satellite.
Another thing I have always voiced my opinion about is, that once the whole country is switched over to digital TV there is very likely to be far more complaints of a continuing nature with terrestrial digital TV reception than ever existed with analogue, as even in relatively perfect installations (which most aren't) trouble can be experienced for all sorts of reasons totally out with the control of the viewer, (e.g: inversion effect etc) but unlike when this happened with analogue where the viewer had to put up with wavy lines or ghost images etc in the background of their picture at least they could still see it, and so were more likely to accept the problem and not immediately kick up about it, whereas with digital reception it results in a range of the most irritating symptoms like constant picture glitches accompanied by squeals on the audio, that is "if" any picture was there to see in the first place!
There are lots of areas in the UK that will never at any time have good reception, and the further removed a viewer is from the ideal line-of-site position then the more vulnerable their reception will be to being interfered with, and this is something that will never change, that being why digital is perfect for satellite as there is the absolute minimum of external factors that can interfere with it, the main one being a really heavy thundery type downpour, the use of a slightly larger dish even minimising this from happening.
I could go on but wont as I already feel that my postings are lengthy enough, but some things have to be said.
| link to this comment |
Sion: On the technical set up screen isn't there an option to disable the "auto service update"? as that would stop the problem referred to from happening.
| link to this comment |
sparky: Thanks for that interesting update giving the results of your findings, and yes! I am sure that you would find the changes suggested to your aerial system to be beneficial all round.
If though you wanted to further experiment with your multi-element aerial to make it have a wider pick up acceptance angle and thereby less critical, is to choose a day that the signal is reasonable stable and note the strength / quality level being seen on ITV3 (mux Ch25) then start removing the directors on the aerial from the end coming inwards towards the active element, and if you remove about half of them that should have just about the desired result by making the aerial less critical in the respect that I had mentioned in my last posting.
You will also probably find the the signal level will not have changed that terribly much either, because the specs / gain curves etc published for aerials are from tests carried out under a strict set of conditions that bear no resemblance to what happens in real life.
| link to this comment |
Saturday 21 April 2012 8:54PM
jay: This could possibly be caused by the boxes memory capacity having been exceeded if a few re-tune attempts have been made, you have to kill everything in the memory by carrying out a "factory reset" procedure first before making another another re-tune, the factory reset also being known as "first time scan" or "default setting", if though you cannot see any of these options mentioned in the set up screen then take the aerial out and re-tune without it to blank out the channels, then once completed reconnect the aerial and carry out a final re-tune.
Any problems are experienced then come back with the model number of the box so that it can be checked on.