All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
Ron Hammond : In addition to that already said, although having mentioned that as far as you are aware Quest is the only programme channel affected, but if the next time Quest drops out its found that you are still able to view (10) ITV3 / (16) QVC or Drama (20) then those programmes are being transmitted by the same multiplex as used by Quest thereby pointing to the problem being caused by a glitch having occurred in the Sony's memory system and with the only way of rectifying this being by carrying out a "first time installation" or "factory reset" on your recorder rather than a normal auto tune, this advice being irrespective of whatever your location might be.
If you have any problem finding this setting then this can possibly be checked out for you if you provide the model number of the device in question.
By the way, that said in my previous reply, re: loopthrough, still applies if its found that you are unable to view the programme channels mentioned.
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Rob : If, as was previously mentioned you manage to test the Sony out on your daughters aerial connection and with the result of this action being a reasonably glitch free C60, then interference from a Tetra transmitter cannot be involved as it would affect the TV no matter where it was installed in your property, however it would though be inclined to point to the source of the problem as being most likely connected with the equipment used by your next door neighbour, as the test you previously carried out using a temporary fly lead bypassing the under floor section of your cable still resulted in the problem being seen until you moved the TV away from the wall.
By the way, I feel it unlikely that any other device that you may decide to purchase would be affected in a similar way to that of the Sony.
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Dsb: Being on a communal aerial system somewhat ties your hands as far what you can actually do is concerned as the level of the signal received has been adjusted by the engineer who installed the distribution amplifier.
However you should still carry out a signal check to see if anything is being received (no matter how low) but by using the Panasonic 635's tuner for testing purposes rather than the TV's, the former being more user friendly as far as "manual tuning" is concerned.
The procedure used being to go into the tuning menu and select "manual tune" then enter C21 into the box (Sandy's HD mux) but do NOT press OK to start the scan, because if anything is being received its level will appear on the strength / quality indicator bar, if though nothing is indicated then press OK just in case the box isnt capable of being used as a signal meter.
By the way if the menu only allows the frequency to be entered rather than channel then C231 is 474.2 Mhz, and if the decimal point is not accepted then 474.00 is quite OK.
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Dsb : Re very last paragraph, the channel referred to is of course C21 and not the typo error of C231.
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Charles Stuart: Click on "Digital UK tradeview" seen in the selection box at the right hand side of your posting and you will see that 195° is indicated as the bearing for Mendip using your post code and with 196° being indicated on Wolfbanes site, this being seen by opening the undermentioned link.
The other point being, as mentioned by Dave Lindsay its not really that critical, however this mostly applies to reasonably near to line-of-sight situations no mater what distance might be involved but though it can become more critical in difficult reception areas, although the final trimming up is done with reference to a proper signal meter and not a compass bearing.
UK digital TV reception predictor
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Rob : Having just managed to catch up with all said, it would now appear that you have proven that the C60 problem is indeed associated with the TV's particular location within the room by the fact of it seemingly operating without fault when moved elsewhere, and with this, as was previously mentioned, somewhat excluding Tetra from being involved provided that the TV is still connected into the same aerial system.
However, purely out of curiosity there is a simple little test that I would like you to carry out should you possess a small multiband portable radio of the type capable of operating over (or any) of the LW/MW/SW bands, the test being to place the radio leaning against the adjoining wall with its volume set to about halfway and then scanning each band in turn, the idea being to note if any "loud" purring or any odd noises are heard at any time during the scan, as spurious non specific frequency interference could be emitting from your neighbours equipment and with a harmonic of one of them happening to land up on C60.
The reason for saying this being, that no domestic devices are capable of sending out an actual (not harmonic) C60 signal except RF modulators used to enable Sky or older (SA) Virgin boxes to send programmes to analogue TV's in other rooms, and although modern Virgin boxes do not have this facility "external" scart connected modulators can be used with them in a similar way to the latest SkyHD boxes, albeit in the case of Sky+HD boxes the modulator is coupled via the I.O port.
By the way, an FM radio could also be used for the test, although in this case the result could be different insomuch that the background "hiss" is liable to fade in the presence of a strong signal, but there are no hard and fast rules as to what will be heard as the main object of the exercise is to note for any changes being heard in the background level.
Another little test I would like to know the result of being, whilst you are observing the glitching referred to turn your TV around at 90° to the wall (facing end on) and see if anything changes.
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SteveK: Yes, 4G or any other filter if it comes to it, always has to be installed preceding an amplifier because if not then said amplifier would be boosting the very frequency that the filter is designed to eliminate, or at least seriously reduce!
I find it interesting though that 4G was found to be affecting channels as far down as D3+4 on C49, as the swamping effect of a 4G transmitter has the maximum effect of C60 but tapering off on every channel downwards from C60, although its all connected with the ratio of the 4G's signal strength relative to that of the DTT signal, and of course you did say that you are located in a poor reception area.
Thanks for the report.
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Dsb: If what you have reported was the result of having carried out the test procedure referred to using the Panasonic then your problem could point to a defect in the line feed from the distribution amplifier used to feed a signal into your property, however in order to give advice appropriate to your situation could you please clarify on the following aspect of your installation that I am not quite clear about.
When you referred to a "communal aerial" and also one mounted in the loft, then are you residing in a property where other residents as well as yourself have a TV aerial socket supplied from a single communal roof aerial, but with you having also managed to fit an aerial in the loft by having access to it?
The other thing that I meant to mention about the test being, that is to connect the aerial directly into the Panasonic and use the TV simply as a monitor for the Panasonic.
Further advice dependant on reply.
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Dsb: Many thanks for the update on the situation, that said by yourself having completely clarified the issue, however now that it has been then if the distribution amplifier in the loft has failed then it would indeed result in the type of problem you are experiencing but though so should everyone else connected into the system, as the various outputs from the amp are fed by a common amplifier meaning that any defect in the amp affects everyone.
I feel your best policy is check with one of the other residents connected into the system to enquire if they are also experiencing similar problems, because if as would be expected they are then access will be required into the loft by one means or another, as it might even be found that the problem is being caused by the power to the distribution amp having accidentally been switched off.
Just purely to get an idea of the signal level being received you should try and borrow a set top aerial and carry out a retune using that instead of your normal aerial connection, if though you are unable to obtain one then just use a length of wire (about 6 - 8 feet or so) connected into the aerial socket of either your TV or the Panasonic, as I am only interested in whether or not anything is received irrespective of pixilation etc.
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Sunday 26 January 2014 12:08AM
pikpilot: Yes indeed! but the filter referred to has a blocking effect on any channel over C60 as 790mhz as mentioned in the write up is halfway between C60 and C61.
I will also agree that Tetra interference had a far greater effect on the reception of analogue transmissions over that of DTT, but dependant on how close the transmission source is to a receiving aerial the form of interference it does create (picture break up) is usually of an intermittent nature.