All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
Tony: If your bedroom is fitted with a normal coax aerial socket, and with the cable from running down to the living room and connected into the Sky boxes RF1 or RF2 output sockets, then is a normal aerial connected into the Sky boxes "aerial input" socket?.
If not, then do you have a normal aerial connection in the property? as Freeview can only work via a roof or loft mounted aerial.
By the way an aerial that was previously used for analogue reception can also be used for Freeview, as there is no difference whatsoever between them.
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John: This could be caused by more than one reason dependant on which transmitter you are receiving Freeview from, i.e: Bilsdale or Emley Moor.
If Bilsdale (@ 26 miles) then as the new COM7 transmitter is only radiating on 17.8Kw compared to the other COM's on 50 Kw then the signal strength received from COM7 on C31 could be a bit on the low side and require boosting.
If you normally use Emley Moor (@ 35 miles) for reception then its COM7 (C32) only radiates on 50Kw compared to174Kw on the normal COM's.
Finally, and a variation on both stations referred to, if you normaly use Emley Moor for reception then Bilsdale could have been accidentally picked up during your retuning exercise, as Bilsdale uses lower channels numbers over that of Emley Moor.
You can check where you are receiving COM7 from by carrying out a signal strength test on the channel, C31 being Bilsdale whereas C32 being Emley Moor.
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paulk: Although having found that both inputs from the LNB appear to be working OK when individually tested on a Freesat TV what are the strength / quality levels being indicated?
Also, when you say that Panasonic can receive BBC2 OK when tuned in via the "other satellite" tuning menu is this by entering 10.773H / 22000 / 5/6 into the box?
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Nick : If indeed you are presently located at Aldeburgh then according to the terrain indicator you do not have a line-of-sight with the Sudbury transmitter as seen by opening the undermentioned link, therefore the signal you receive from that station is purely via diffraction, i.e: signal bending around obstructions.
Reception under these conditions is always vulnerable to problems relating to weather conditions and the effect it has on the surface of the terrain as far as its reflective properties are concerned, plus of course the effects of any atmospheric condition changes that may be in evidence at the time, all of generally causing the signal level to gradually drop off to the extent that it starts to encroach on the minimum level required for the digital receivers decoder to operate correctly, any further reduction taking it under this level whereby reception suddenly vanishes giving the impression as though someone has done something, or even that the transmitter has failed! albeit that the signal is still there.
I suggest that the next time whatever you are viewing vanishes you should immediately go into the TV or boxes tuning menu / manual tune and enter the mux channel number of the programme being viewed but with this action NOT being followed by pressing search or scan as not doing will cause the TV or boxes tuner to act like a signal meter, the indications from same being noted for the purpose of cross checking with that obtained when reception was OK.
As far as levels are concerned, its not really possible to give levels with any sense of accuracy as it all depends on the calibration of the equipment being used, hence vast variations in levels can be experienced.
However, on the older Humax SD boxes such as the PVR-9200 / 9300 a signal strength level of around 70% coupled to a 80 / 100% quality could be considered as being good.
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Tony: Provided that your old aerial is still in satisfactory condition then it can be used for Freeview reception, although more detailed info with regards to your reception possibilities could have been given if you had cared to indicate your location, this in the form of a post code.
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nick : And of course the link referred to which I unfortunately omitted to paste on.
Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location
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paulk: If the 8 means strength and with the 9 being quality then the dish alignment would appear to be perfectly OK, which of course also includes the two coax feeds from the LNB by each of them having been tested out on your Freesat TV.
The only thing I wasn't quite sure about is whether or not the problem channels are indicated on the programme guide? and its just that nothing appears when one is selected?
I would though like you to try a test by manually tuning in the Freesat home data transponder on 11.428 H 22000 and see what's indicated, because as things presently are its beginning to appear that the problem is being caused by either a fault having developed in the tuner or possibly in the circuitry involved with sending commands to the LNB.
By the way, have you already tried disconnecting the box from the mains supply for about 30 seconds or so before reconnecting it again? as although I fully appreciate that you have already carried out a factory reset, this in the technical sense isn't exactly the same as killing the power.
Another point I was wondering about being, do you have a simple voltmeter capable of measuring say up to 25 volts DC?
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paulk : Typo error correction, Freesat data transponder on 11.428H should be 27500 and "not" 22.000.
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Kevin: If your dish is positioned with a clear view of the S/S.Eastern skyline and with no evidence of it suffering from partial obstructions from such as tree or bush foliage blowing across its path, then your problem is either being caused by the dish mounting brackets not having been tightened enough and allowing same to move in the breeze, or alternatively the coax possibly being fractured where its leaves the "F" connector on the LNB caused by the cable not having been properly restrained with the aid of a cable tie.
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Sunday 5 January 2014 9:04PM
KEVIN GARDINER: Sorry for the delay in replying but I was taking time to digest all said your detailed report before I replied.
It would appear to be the case that nothing you do results in an error free signal, and which as was previously mentioned could (but not definitely) be caused by receiving an excessively high signal level therefore this requires attenuating, preferably by using a variable gain type attenuator of the type seen on the link.
However, although I also feel that your bedroom positioned set top antenna is inviting quality errors into the signal you could use it for test purposes, being, by selecting a channel on the TV and then leaving it sitting on its signal test screen, this then followed by positioning the aerial low down near to the floor level to reduce the signal pick up properties followed by "slowly" rotating the aerial to see what effect it has (if any) on the bit error rate, with this being irrespective of what the strength may indicate no matter how low it might be, giving an update on the results.
On the subject of your location, tree foliage can be a menace to digital signals and especially if HD is involved, and although I fully endorse your idea of using a Log periodic aerial (DM log being ideal in your situation) you should initially position it lower down rather than at the top of the mast as this does not always achieve the results expected.
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TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay