All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
Pete: No problem! and checking on your Freeview reception possibilities for the area given suggests that its best to keep your Sky boxes RF output channel to between Ch's 64 - 69 as Winter Hill's highest mux channel is Ch62, this station being indicated as providing an excellent level of signal at your location.
You should also try a test without using the magic eye, but before doing so change the lead from your Sky box over to the RF1 output socket so as "not" to have the 9 volts power from the RF2 output going into your TV, as the latter "might" short circuit the power depending on the TV's input circuitry.
If though the problem still persists then the final test you can try is to temporarily place the 2nd set near to the Sky box and with a jumper lead coupling the two together.
As far as a weak signal is concerned, as aforementioned you are indicated as being able to have good reception from Winter Hill, but though just to get an idea of what the reception is like connect the aerial straight through to the 2nd TV then carry out a signal strength / quality check whilst on either BBC1 or ITV1, as if your aerial is slightly deficient in any way or you have some local obstruction to the signal path from the transmitter, this might be causing you to receive a level of signal that's hovering just above the threshold for reception whereby the slightest obstruction to this (i.e: through Sky box) is taking it under the threshold referred to.
By the way you should be able to carry out the same test even if the screen is blank so long as you have BBC1 or ITV1 selected, because even although the screen is blank the signal will still be there but just under the cut off point as far as resolving a picture is concerned.
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Michael: I was having a look back through your various earlier postings for purposes of checking the history of your problems, but though whilst doing so came across a statement that appeared somewhat contradictory and which I couldn't quite fathom out, and so I would be obliged if you could clarify the following as far as the devices you are using to receive Freeview is concerned.
The statements referred to being:
>> Our main TV is analogue so has to be fed by either out Toshiba RDXV59DTJB2 HDD recorder or our (very) old Sagem Freeview box. <<
>> Is it plausible that the recorder and Freeview boxes are unable to cope with quality variations that are no problem to the TV? <<
What TV is being referred to in the latter statement?
However no matter what is being referred to it should be appreciated that no two Freeview devices have the same sensitivity tuners unless they are identical models to each other, this being the cause of the differences in performance that you have noticed, Panasonic TV's and Humax boxes being devices fitted with two of the best tuners around, and capable of giving reasonably glitch free reception in circumstances where other devices would be glitching every 30 secs or so.
The other point to remember being, that if when observing a signal its strength and quality is seen to be continually fluctuating (especially quality) when its known that your aerial is electrically sound as far as bad connections are concerned, then the problem is in effect out with your control, as its liable to be caused by either atmospheric reasons allowing distant stations to be picked up thereby blocking local reception, or that the problem is due to the intermittent effect of tree foliage blowing about, worse obviously if wet.
In both cases about the only thing a person can do is make sure that the signal being received is at a high enough level above their receivers cut off threshold whereby when the signal drifts downwards its still above the cut off point and not constantly dipping under it.
Occasionally moving the aerial a few feet either way (left or right) can help the situation, but frequently its at the expense of some other mux, so its really a hit and miss situation.
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Simon Parsons: I would try changing the Sky boxes RF modulator to Ch36 and carry out an "analogue" auto scan on one of the TV's you are having a problem with.
Just out of interest are you using a magic eye on any of the remote TV's? as if you aren't then make sure that the Sky boxes RF2 power is turned off.
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colin: Basically yes! or of course you could just go ahead and allow it to update whatever as that would stop the message from appearing again.
You should also check the set up menu on your TV as there might be a selectable option to stop these messages from appearing, but it depends though on the model / sophistication of TV as on many types there isn't an option to stop them.
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Michael: One particular thing you have said is extremely interesting, this being the results you obtained with the distribution amplifier switched off, because although distribution amplifiers boost the signal to varying degrees dependant on the spec of the model used, on the other hand when they (all types) are switched off they act like an attenuator having been placed in line with the aerial, this being why if done on an analogue signal it always resulted in a grainy picture.
The point about this situation being, that you must be receiving a reasonably good level of signal at your location for it to overcome the attenuation effect of an unpowered amplifier being in line, and so although I realise that you obviously require the distribution amplifier for purposes of feeding the signal to other locations its possible that the overall signal level created by this is slightly too high (for some devices) whereby an attenuator being placed in-line with the amplifiers "input" could help the situation, as an excessive level of signal displays exactly the same symptoms to one that's on the weak side, including "false" low signal indications caused by instability in the tuner.
I would therefore suggest that you try a test on one of the TV's by connecting its feed directly onto the aerial lead that feeds into the distribution amplifier albeit I do realise that in most cases this is a bit inconvenient to arrange, but though its the type of test that is necessary to evaluate what's happening.
Another point to note is, and although very unlikely to be applicable in your situation, but on "some" occasions when the signal quality is observed to be continually fluctuating this can also be due to a signal being on the verges of being excessively high, because signals in non line-of-sight situations tend to drift up and downwards in strength throughout a 24 hour period, and if they are hovering at the top end of high (with good quality) and they drift slightly further upwards then as soon as that happens the quality drops, this resulting in the fluctuations referred to.
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Simon: There just has to be some simple explanation to your problem, as virtually nothing can stop an analogue signal from getting through to a remote position except of it was clashing with a powerful Freeview signal, which of course it isnt if the boxes modulator is now on Ch36.
Although I doubt if this would make any difference but for a test couple the feed to the 6 way amp onto the boxes RF1 output rather than RF2, do "not" put RF2 into the main TV's aerial socket.
If this still makes no difference then position one of the problem TV's near to the Sky box and couple its aerial directly into the Sky boxes RF1 (not RF2) and then select "analogue" on the TV and carry out an auto- scan, as it just has to work! although if not its the TV at fault.
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A Parker: Most likely because your dish is slightly misaligned, if a standard Sky box press "services" 4 - 6 and check that both strength and quality is indicating the equivalent of 60% minimum.
If a Sky HD box: Press "Services" on your Sky remote control and you will see the main
menu with "Options" highlighted.
2:- Highlight the Settings menu using the right arrow button and press select.
3:- Use the left / right arrows scroll to "Signal" and press select.
4:- The grey bars displayed will show you the strength / quality of the signal.
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Brian: Yes! as on October 24th HD will be starting on Mux Ch55 and with the power increasing to 20Kw on the PSB transmitters and 10Kw for the three commercials, all transmitters presently operating on 800watts.
Needless to say that two retunes will be necessary, one on October 10th when the BBC switches channels as well as increasing power, and with the final retune being on the 24th when the others change channels and increase in their power.
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Michael: Just a small addition to that said, its not exactly unknown for a distribution amplifiers internal power supply to fail and especially during the warm weather, and so although what was mentioned about the amplifier still applies in every way its best to check that its still working.
The procedure is to have the amplifier switched on and carry out a signal strength / quality on a reasonably stable channel noting the readings, then connect the TV' aerial feed straight into the aerial and carry out a second check noting what the difference is, and provided an excessive level of signal is not upsetting the readings what's indicated with the direct aerial connection should be "slightly" lower than before.
If though its higher, then either the amp is defective or the signal level is excessive.
By the way, I will not personally be available to give further assistance until about next weekend as I will be on holiday, although someone else will probably answer any query you might have.
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Thursday 30 August 2012 12:20AM
Pete: Although a weak Freeview signal can cause difficulties if passing it through a Sky box, another possible reason for your problem could be that the RF output channel used on the Sky box is the same as is used by Freeview, although that would only have a serious effect on a particular range of Freeview channels.
I would normally have advised you regarding the RF output channels NOT to use, but knowledge of your location (post code or one from nearby) is necessary to be able to do that.
Could you also mention the model of Sky box that you are using?