All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
Miranda Stanley: As you may possibly have noticed engineering work is presently taking place at the Oakley Mynd transmitter and with this being the most likely reason for your problem.
Another aspect being, that even when this work is completed you may still experience problems due to large swathes of the South West of the country being affected by the atmospheric conditions prevailing at this present time, this being the type of thing that would have resulted in ghosting / double images / wavy lines etc on the picture during the analogue years whereas with digital transmissions it kills reception, needless to say do NOT be tempted to carry out a retune as all you will achieve is to lose the channels already stored in the tuners memory and with this then requiring frequent re-tunes to recover them , whereas if nothing had been touched they would have returned of their own accord.
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Neil Killip: Just checked C29 in the Stamford area and its being at received at full strength with zero bit error rate problems, this suggesting that your difficulty in receiving this channel is being caused by some form of localised interference, have you as yet checked with a neighbour or someone else nearby to find out if the problem is widespread or alternatively specific to your installation? although it could also be associated with the current wave of high pressure that is responsible for distant stations being received, and which if they are operating on the same mux channel as the local transmitter will corrupt its data hence killing reception.
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Pauline McDougall : There isnt any engineering work being carried out at the Winter Hill transmitter, and so I suspect that your problem is being caused by the same reason as is presently affecting numerous other viewers located in certain parts of the country, insomuch that the current wave of high pressure is allowing distant stations to be received that are transmitting on the same mux channel as your local station hence killing its reception through data corruption.
Absolutely nothing can be done about this except to bide ones time and wait for the situation to improve.
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Scott: Boosters have a role to play in many installations and indeed in some are a necessity, especially so the variable gain types, as in many non line-of-sight situations its frequently found that one of a main stations six muxes is being received at a considerably lower level than the rest and with it being impossible to correct the situation even with the usual minor adjustments being made to the left / right positioning of the aerial, this being where the variable gain booster comes into the equation by it lifting the level of the signal whilst viewing the offending channel, then "if necessary" lowering it again to avoid any possible signal overloading problems on normal channels, although in most of the cases (brand model dependant) it can usually be left advanced.
As far as 4G is concerned, the filter should always be placed between the aerial and the boosters input before any amplification takes place, however there is a lot of scaremongering around about 4G such as seen in some recent postings where the finger is being pointed at it as a possible reason for the bad reception being presently experienced by many in certain South Western areas of the country, when in actual fact the problems are being caused by the current wave of high pressure enabling distant channels transmitting on the same channels as the locals to be picked up and corrupting the data stream from the locals, this resulting in the tuner being unable to decode them hence either a "no signal" screen or a severely pixilated picture accompanied with bursts of screeching audio.
On the subject of those three additional muxes, I am afraid I do not share the glowing reports as far as their predicted coverage is concerned, as in many non line-of-sight situations the slightest drop in TX power already results in reception problems for those residing in less than ideal situations, and so considering that Black Hill radiates with an ERP of 100Kw I just cant see satisfactory reception being possible in many areas from a transmitter only radiating with an ERP of 9.4Kw such as used on C32, LG being worse at 5Kw on C51, needless to say I will be waiting with interest with regards to exactly where the signal can received and where not as I am quite acquaint with the landscape of the areas involved.
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JLM,Ely: Although aerials of the type mentioned do serve a purpose its really more in an aesthetic sense with regards to where they are mounted rather than technical, as their reception properties are no more than what would be achieved by connecting a very short piece of wire of say 30" or so arranged in a slim rectangular fashion and connected each end of the wire directly across the aerial input socket of any 30db booster, whereas a small (2'.6"/ 76cm) discreet log periodic type aerial fitted under the gutter or alternatively in the loft and coupled into a booster of around 20db or so would in most cases give far superior results.
However, if prior to the problem presently being experienced you been having perfectly satisfactory reception from this type of aerial then obviously something has changed and being something which "might" possibly be associated with the difficulty many are presently experiencing of either no, or alternatively poor, quality reception and caused by the prevailing atmospheric conditions enabling distant transmitters that operate on the same channels as local stations to be received and which corrupt the data stream from the local stations muxes, this in turn resulting in the tuner being unable to decode the signal hence no reception.
Although understandably many are reluctant to do this, but purely for the purpose of elimination you should make a local enquiry with a neighbour or whoever to find out if others are being similarly affected before concentrating on the fault possibly being associated with your aerial, although I will say that an intermittent fault in an aerials power supply (bad connection on the main smoothing capacitor) can result in a form of intermittent fading then rising.
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Lesley: No issues have been reported as far as the Bluebell Hill transmitters are concerned, but though numerous viewers are being affected in various wide ranging Southern areas of the UK caused by the current wave of high pressure, and so to eliminate the possibility of this being the cause of your problem you should make a couple of local (very) enquiries to determine if others are experiencing similar difficulties, as the chances are that they might well be!
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JLM,Ely: Thanks for the update on the situation, and pleased to see in your latest (09.46pm) posting that all is still indicating OK.
Although the reason for your problem, and with the rectification of, somewhat indicating that you must be located in a good area for reception otherwise the signal received using an aerial of that design when having been mounted in error as far as polarity is concerned would have been very poor right from the start, although the fact of your reception dipping in the evenings was an indication that the signal could not have been that stable, which of course is only to be expected with any aerial mounted incorrectly polarity wise and especially where slight distances are involved, as the aerial will try to grab as much of the signal as possible meaning that it will be prone to picking up reflections from the horizontally polarised signal that get bounced off objects along the way, and signals of that nature are always sensitive to changes in reflective surfaces that generally occur between day and later evenings caused by such things as moisture etc.
Of course slight signal drop off in the evenings is something commonly experienced in many installations and indeed will still be occurring, but with the effects of not now being noticed because the strength / quality that your signal will now be running at will be well in excess of the receivers cut off threshold level.
By the way the differences referred to would not be noticed on a Panasonics signal check screen, as Panasonics (and I use one) are inclined to indicate levels as being far higher than they really are when checked against say a Humax PVR, one of the few devices around whose indications are more in line with that obtained from a more professional signal strength meter albeit that its indications are in dB/m and not percentages such as indicated on a Humax.
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Rob: This would suggest a transmitter programme feed error as both ITV1 and ITV+1 are on the same transmitter, West news being fed to the Mendip transmitter.
However purely for the purpose of verifying that nothing odd has happened at your end carry out a signal check on both ITV1 and its +1 service and noting the mux channel number indicated, as in both cases it should be Ch44, whereas Mendip is Ch54.
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JLM,Ely: The 5 volt via the aerial socket facility is intended to supply power to remotely positioned amplifiers such as mast head types etc and with this being irrespective of whether or not they are actually mounted on the mast or in the loft, the main difference with those types being that none of have internal power supplies as their amplifiers extract the DC power for the amplifier from the coax without having any effect on the RF signal being fed back to the TV, however this facility is only found on certain model numbers within only one or two brands but with Panasonic's not being one of them, at least not as far as any that I am personally aware of nor did I see this facility mentioned in any of their manuals picked at random from the range I use for reference purposes, this also applying to your particular model of BT vision box.
With regards to the comment made by the BT engineer when referring to signal strength, this somewhat backs up my own statement regarding you being in a good area for reception, because if you were not then you would most likely have experienced reception problems right from day one due to the polarity error, the fact of the BT engineer not having picked up on this can only in my opinion, be put down to the possibility that he hasn't actually seen one of those types before, although I would have thought that the fact of the device having been mounted facing upwards towards the Sky might have caused him to latch on to the possibility that something was not quite correct about the installation.
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Monday 23 September 2013 8:07PM
Helen Williamson: Many thanks for the update as I was curious as to what your neighbours reaction would be when you approached him, because some types immediately take on a defensive stance if any criticism is made on what they have just done, however yours seemingly being an easy going sort of person (maybe too much so!!) who was not even aware of the installers positioning error.
I will say though that the installer (if experienced?) should have been aware of what he was doing, still the main thing is that you have successfully paved the way to having the problem rectified without having generating any bad feelings, as one never knows what to expect from some people.