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All posts by jb38

Below are all of jb38's postings, with the most recent are at the bottom of the page.


Edd: No two TV's have the same sensitivity unless they are of exactly of the same brand / model, however and although exceptions can apply, but these differences usually only show up in areas where the signal levels received are inclined to be on the low side, but though this being where its impossible to assess as to whether or not this is liable to be applicable in your case as you haven't given your location, this preferably in the form of a post code or at least one from a nearby shop or whatever.

By the way, tuners used in Samsung equipment generally demands a good level of signal for satisfactory operation.

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Lisa: On back tracking through the postings made over the last few days and NOT seeing your name mentioned did actually make me wonder as to whether or not your problem had magically rectified itself, however the content of your latest posting has somewhat answered this.

Anyway, with regards to your idea of contacting someone connected to the switch over scheme for purposes of making a complaint, obviously what you decide to do is entirely your own decision, however I would advise against taking such action as its almost a foregone conclusion that any reply that you may receive from whoever will put the reason for your difficulties firmly down to some aspect concerning your installation come equipment that you are using.

That said, and without going over too much old ground, but your problem is simply because that you are not receiving two of the three commercial muxes which are transmitting on Ch's 48 - 51 - 52, insomuch that you ARE picking up programmes on ArqA Ch52 like (11) Pick TV or (19) Dave, but not though any that's on ArqB Ch48 such as (12) Yesterday / (24) ITV4, a similar situation applying with SDN Ch51 that (10) ITV3 or (38) Quest is on.

So getting back to the test I suggested you try by manually tuning in mux Ch48 as well as Ch51 and this being where you had mentioned about the bandwidth being requested, can I take it that you did select 8Mhz "before" pressing scan? as if you did not or had selected 7Mhz then nothing would be picked up. If though you did select 8Mhz and nothing was received then I would like you to select (11) Pick TV and check what the signal level / quality is indicated as being, as I still suspect that the signal is there but sitting just under the level that your tuner can operate on, Ch52 possibly having the slight power edge over Ch48 & Ch51 and that's why you can receive it.

There is of course another and much simpler way that you could determine the cause of your problem, that being to try and borrow another TV but not a Samsung brand, as most Samsungs do not have sensitive tuners.

Also, have you checked with any neighbours to find out if they experience similar problems to yourself with reception of either ITV3 or Yesterday? as only these two are required for testing as they represent the two muxes, but though if they can pick these channels up then have a look up at their roof to make sure that their aerial is pointing in the same direction as your own.





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Ron Crisp: If you are a follower of certain Sky package channels that can only be viewed via a Sky subscription then you will obviously have to stick with Sky, but what you should do is check through a few of the programmes that you normally view on Sky and after selecting each of them one at a time remove the Sky card whilst viewing it, as that will soon indicate the channels that can only be viewed with an active card, exclude Pick TV (152) though as although that would vanish although its still viewable without a subscription, the card having to be installed as its encrypted.

I personally favour Freesat for reception because just like Sky its 99.9% of the time totally reliable, whereas Freeview can be prone to suffering from a variety of annoying reception problems especially in country areas, transmitters covering your area being Winter Hill @ 11 miles or Emley Moor @ 26 miles, although the second part of your code may indicate potential problems with either as this does not show using only BB4.

Another aspect is that Freesat has a few programmes that Freeview might not and vice-versa, likewise Sky without a subscription giving another variation, and so your personal viewing preferences would really dictate your course of action, although I would never hesitate in recommending a Freesat HDR to anyone that demands glitch free reception.


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Jon: Atmospheric conditions generally cause most signals to vary over a 24 period and its just that most people do not notice this variation when their signal is received at higher levels and well away from the cut off point of their receivers tuner, this commonly known as the "digital cliff" threshold, as should the signal not be running high enough above this level then any slight drop will allow it to encroach on the cut off point resulting in constant picture pixelation or freezing, and with any further drop cutting the picture off altogether.

I think your test somewhat proved the point about the lack of sensitivity that Samsung tuners can suffer from, I will say though that if you used a booster of say 10db+ purely on the feed to the offending Samsung then that would keep the signal level running well away from the R41DB's cut off point, this most likely resulting in it being more reliable.

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J
Feedback | Feedback
Thursday 24 May 2012 9:05PM

Lesley: Its impossible for anyone to offer advice on your problem without having knowledge of your exact location, pref: post code or one from nearby, as only a post code will enable access to the reception predictor so that the levels expected in your area can be assessed.

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Claire: Its just not possible for anyone to offer advice on your problem without knowledge of your location, a post code or one from a nearby shop etc being suffice, as there is no way of checking on the signal levels expected in your area without this info, especially when a person can be receiving from more than one source.

You should never carry out a re-tune when channels appear blank as they will not actually be lost from your TV's memory, but just not being picked up for some reason or another like a glitch in the transmitter, as all retuning does is to wipe them from the TV's memory which necessitates a further re-tune to recover them rather than just checking now and again to see if they have returned.

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Matt: Have you as yet checked where your aerial is facing towards? although I do have to say that irrespective of where it might be facing that "if" when you selected to manually tune in Tacolnestons BBC1 on mux Ch55 and you didn't see the signal strength being indicated "as soon as" you entered 55 into the box (no need to scan) then that's bad news, as using that procedure effectively turns your TV into an RF sniffer by-passing the cut off threshold that stops a picture being received under a certain signal level, generally known as the "digital cliff".

The aspect that makes it bad news being, that even if the aerial you are using is in the wrong grouping then as far as this sort of test is concerned it makes no difference, and indeed in many cases it doesn't either if its not a test!, as a person will "still" receive a signal but just at a level that's somewhat less than it would be if using an aerial in the correct grouping, although if you do have a group that caters for Sandy then that's at the better end of "incorrect" than it would be if it catered for Tacolneston and you were trying to receive Sandy, as differences are much greater when an aerial is too short for the frequency being received.

I do have to say though, that when problem's are experienced when using an out of group aerial that its usually always because that the reduced level is resulting in the signal hovering around, or even dipping under, the cut off threshold I referred to, but its not by any means a "black and white" case that an out of group aerial will not receive something as there are always shades in between, as it all depends on the level of signal that a person receives.

By the way, I did have a look at the terrain predictor for between yourself and both transmitters involved and didn't actually see any obstructions being indicated, of course not that this really goes for anything, as a person could reside behind either the Sherwood Forrest or a few tower blocks and it would still show a clear line of sight, as terrain predictors take no account of anything other than of a natural hill nature.


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jon: On the subject of the variable gain masthead amplifier, is this made by Vision? however I am afraid I beg to differ from whats been said insomuch that the facts are, that if when the gain control on a variable aerial amplifier is slowly advanced and its noticed that this action is actually resulting in the signal level seen on the TV's check screen start to go down rather than up, then either the device is defective and is not working correctly, or alternatively its because the signal level being received by the TV is on the verges of being excessively high and is starting to saturate the tuner, as this is one of the main symptoms observed with this type of problem, no exceptions existing to either of these reasons mentioned as one has to apply.

Of course, and although its not so commonly experienced, but the actual aerial amplifier itself can also suffer from being overloaded, and with the symptoms seen being almost identical to the ones already mentioned on the TV because of the fact of being able to alter the internal operation of the amplifier.

The only reason for me mentioning this being the fact of you stating a 100% signal level being seen on one of the Samsung's, as that is too high as it does not allow an overload safety margin for a tuner, and as I have mentioned to others that the next step up from 100% is creeping instability, that is "if" when you stated 100% level that you are actually meaning the strength and not the quality?



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J
Hannington (Hampshire, England) transmitter
Saturday 26 May 2012 12:03AM

RichardS: I fail to see what advantage a grouped aerial would have on the situation when the signal observed on one of the Samsungs is perfectly OK and indeed possibly excessive, this as well as the fact that the aerial might already be a grouped aerial anyway "if" it was installed for pre-switchover Freeview, as Hanningtons channels spanned 40 - 50 whereas now its 39 - 47.

The other point being, that a TV or box requires a certain level of signal to operate correctly with the minimum of glitches or any type being observed, but whether the level fed into the set comes directly from the active element on a so called higher gain aerial, or alternatively from a lower gain type that's been boosted, the TV will respond in exactly the same way as its the level that counts.

The reason I stated "so called high gain", is because that its only in near line-of-sight situations that this type of aerial might prove as an advantage, as if its used in a situation where near line-of-site is not the case then the directors on the aerial are liable to become restrictions to a signal that is deviating slightly in the angle received from its direct path, something which generally happens in situations where reflections from tree vegetation etc is applying.

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Matt: The reason you are receiving Ch21 with no quality being indicated is because that the LG42LD450 you have is an "HD Ready" TV with a DVB-T tuner fitted and NOT an DVB-T2 type which is necessary for HD reception. In other words the screen is capable of producing an HD image but from an external HD source.

However your Philips PVR is capable of receiving an HD signal, and so if you couple that into your LG using an HDMI lead and with the aerial going directly into the Philips, then what type of reception do you get on that?

Try a manual tuning test on the Philips using the same procedure as was done on the LG.



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