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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.


Ludlum: What you have reported just really backs up the fact that in most reception problem cases nothing can really beat that of an on-site investigation by an experienced and suitably equipped person.

Of course I suppose you landed lucky by the fact of being fortunate enough to have an aerial installer working next door at the time coupled to the fact that the problem referred to was actually in existence, rather than in many cases where the complaint might be relating to something of an intermittent nature whereby Murphy's law usually dictates that the chances of it NOT being in evidence when someone arrives to investigate are quite high, and which in turn can in some cases trigger a time consuming exercise if the problem is suspected as being caused by factors external to the property.

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Darren Cotton: As far as the problem affecting both of your media centres is concerned my reply was purely with reference to your query regarding 4G, however I will say that although nothing has been posted on the TX fault reporting site nor is any engineering work taking place at Waltham as far as Freeview transmissions are concerned, albeit it is / was for other services, but though on having checked out some PVR recordings made from Waltham over the last week and in particular one involving daily recordings made on ITV1/PSB2 revealed that glitches of the more severe variety have indeed occurred on quite a number of occasions.

That said, an aspect of these glitches I did find rather interesting was the timing factor involved, insomuch that the glitching always seemed to clear up about 20 seconds or so prior to an advert break, staying that way during the adverts before returning to the previous state when they were over, adverts being sacrosanct as far as NOT giving anyone connected to those who may be paying for same any cause for complaint.

This may of course have been purely coincidental, but without putting too fine a point on it I doubt if coincidence was involved.

As far as a four way booster is concerned, if your media devices tuners can indicate signal quality then the booster will always improve things so long as the signal quality when observed beforehand is not seen diving to zero.

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Loft aerials | Installing
Friday 14 June 2013 6:02PM

Muz: Thanks for your update on the situation and that by your action on having changed the aerials polarity did indeed have the desired result, at least now that your signal is much stronger it will give you a better leeway before suffering from any problems should it drop again through changes in atmospheric conditions, something generally experienced to a greater degree where the line of sight is obstructed closer to the receiving end of the signal such as applies in your situation.

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Feedback | Feedback
Friday 14 June 2013 10:55PM

Floyd: With reference to your latest up date, but also referring back to your posting on the 9th @ 7.46pm where you had mentioned that both buildings have a rooftop aerial, the masts of having been observed as being mounted on the gable ends of each block which are positioned at right angles to each other, this then suggesting that both blocks have their own identical communal aerial arrangements.

This being the case, then rather than your problem being caused by an incorrect type of aerial having been fitted its far more likely to be caused by a defective connection somewhere on the aerial system starting from the aerial itself downwards.

However, I do suspect that the fault is likely to be located on only the section from the aerial to the distribution amp or indeed even the distribution amp itself being defective, the reason for saying this being that each of the three apartments in your block are likely to have their own feeds from the dist / amplifier, but by your investigations having revealed that no-one in your block gets good reception then the problem has to be prior to the dist / amplifier output feeds, as it would be a bit too coincidental for all three feeds to be faulty.

As far as the wire that's seen linking across the roof of the blocks is concerned, if your block is not fitted with a dish and yet the apartments have a satellite connection? then the wire referred to could be for the purpose of carrying the four feeds from the dish mounted on the other block across to your own blocks multi-switch unit, a device that's always used to supply satellite feeds in apartment blocks.

Hope this helps to clarify the
situation a little.

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Diagnostics - old version
Friday 14 June 2013 11:05PM

julie: Are you really referring to a Freeview PVR? that being a Freeview box most of being with twin tuners that can record one channel whilst recording another.

Because if you? are then the aerial goes straight into the PVR and with the RF output from same being linked into the TV's aerial socket, a scart cable connecting the PVR into the TV, and although on most TV's switching the box on causes the TV to switch over to the PVR, in some cases you have to press the AV button on the TV's remote control to access it.

What model of PVR are you referring to? that is "if" you are!

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CC40: Nothing has changed recently as far as the ITV1 mux channel is concerned, but as far as your problem is concerned I can say that what you have described is exactly the main symptom experienced by many with older equipment when first trying to tune in a transmitter channel with a negative offset on its TX frequency, i.e: it transmitting at slightly under the exact frequency associated with the channel number as indeed applies in the case of Waltham's PSB2 / TV1 mux, something which although having no effect on the majority of tuners used by a wide range of equipment can however cause problems on equipment using tuners with a somewhat limited AFC (auto-frequency control) range that resists being pulled downwards past a certain point, this being why the action of notching up a channel then back down again (or vice-versa) can on occasions "catch" the frequency.

Another factor that had an effect on how often a person might experience this problem was connected with the signal strength being received, it being slightly worse on weaker signals, and so I was just wondering what kind of signal strength your Media Centre is operating with? as I feel that the problem you are now experiencing is as a direct result of the action of retuning having exposed a deficiency in the tuners AFC range, this possibly only being revealed now by the signal level received at this present time being at a slightly different level to that applying when you had first tuned it into the station.

I am unaware as to the exact model of tuner used in your Media Centre, but can you recall ever having received messages regarding software up dates? and if so did you carry them out?



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CC40: Now its known that the tuner in question is a 290e stick and that the frequency has been manually tuned in then obviously the usual reason for the symptom as described in my previous reply will not (or should not) be applicable in this case.

However tuner stick problems are notoriously difficult to diagnose by the fact they are not being used with standard hardware / software combinations such as used in dedicated Freeview devices, and the difficulty you are experiencing has to be caused by something having changed in your system during what I assume was the retune you carried out when Waltham's BBC dropped down to Ch49, because as mentioned in my previous reply the technical aspects of the actual ITV transmission has not changed in any way except possibly for minor changes in its reception strength.

And on the subject of signal strength, what you have reported could suggest that you are located in a high signal strength area or alternatively might be using a booster in line? if you are then I would temporarily try by-passing it so as to reduce the signal going into the tuner, because should it be a little too high on Ch54 this can result in intermittent signal blanking on ITV and other programmes on the same mux.

Another test you could try is to temporarily remove the HD stick just in case the two sticks are pulling the USB sockets power supply down by the current being drawn by them, as although your system might well have previously been working perfectly OK should the signal now being received on Ch54 be a little "over the top" then this would have more of an effect if the stick was operating at a slightly reduced voltage, as indeed any tuner would.

Other than these things mentioned I cant really think on any other reasons for your problem other than going through all the settings on the PC associated with the tuner. (Ch49 be) 

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Emley Moor (Kirklees, England) transmitter
Saturday 15 June 2013 6:08PM

Dave Lindsay / Steve: As I see it from my point of view although a group B aerial (Ch's 35-53) would under "normal" circumstances be a far safer bet for the reception of Emley Moor (Channel span Ch41-Ch52) in cases where the possibility of 4G interference was a definite issue, the slight deficiency that most aerials have on the last few channels at each end of their coverage range being in this case a plus point rather than normally the reverse, and indeed the protection afforded by using an aerial with a restricted top end coverage could even be further reinforced by fitting a 4G filter as well.

However the reason I said "normal" circumstances is because the set up as described would only be satisfactory in cases where it was previously determined that a reasonably strong signal was being received on the high channels before any alterations were made otherwise the COM channels will be difficult to receive, and so everything hinges on what like Steve's reception is (signal / quality strength wise) on Ch52 / Ch51 / Ch48 and whether or not they can stand a slight reduction in signal strength, which of course they invariably would do using the aforementioned set up.

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Full technical details of Freeview
Saturday 15 June 2013 6:21PM

John Taylor: If the location entered is that of your friends then at approximately 1 mile from the Crystal Palace transmitter experimenting with the aerial mounting positions usually brings results, they key thing being that the aerial should be as simple as possible and not amplified in any way such as found on certain set top types.

If though the location referred to is not that of your friends then further advice can be given if their whereabouts is indicated, a post code or one from somewhere nearby being suffice.

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Full technical details of Freeview
Saturday 15 June 2013 6:48PM

Steve Leonard: It isn't a coincidence, as wireless senders that operate in the lower band of 2.4Ghz can interfere with Wi-Fi, cordless phones etc as they use the same frequency range, although in the case of them interfering with Freeview its not the 2.4Ghz signal that causes the problem but the high level of digital interference that radiates from the casing on many of these devices, likewise they should never be positioned anywhere near to a Freeview device or the coax cables to or from.

The later versions of Video senders are a safer bet as they operate in the 5.8Ghz band, although just like in the case of the 2.4Ghz units they should not be positioned close to Freeview devices.


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