All posts by jb38
Below are all of jb38's postings, with the most recent are at the bottom of the page.
David : Re: your query on Film4 HD. Please disregard that said in my reply made yesterday @ 9.03PM, as further checking has revealed that Film4 HD (whether +1 or not) is not available as yet on the Freeview platform, and even although +1 is being transmitted on an HD transmitter its only being broadcast on SD.
This being the case, there is no real advantage of using Film4's +1 service on (45) over the normal SD transmission on (15), that is unless having a specific reason for wishing to view Film4 on its +1 service.
Apologies if any confusion was caused by this error.
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Eve : As both channels are being received OK in another room, then the problem is with the TV.
The best way of getting over the problem is by carrying out a "reset" the TV, this on some brands being referred to as "default setting" or "first time installation", the main point being that everything stored in the TV tuners memory has to be cleared followed by carrying out a normal retune.
Although the aforementioned is almost guaranteed to rectify the problem, sometimes success can also be achieved by removing the aerial connector from the TV followed by carrying out a retune, this also deleting all stored in the tuners memory, checking it has by "reconnecting the aerial" and ensuring that selecting any channel results in "no signal received" message. The final stage being to carry out an auto-tune to load the channels back into the tuners memory.
By the way, indications suggest that you are receiving Freeview from the Oxford transmitter.
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David Nash - If the lower gain output test has made no difference to the situation, then I cant really see any way forward other than by replacing the Wolsey, but though with the replacement distribution amplifier being of the somewhat less powerful variety, as you only require the absolute minimum of gain just enough to compensate for the large number of outputs, whether they be presently used or not.
However, there is one final test that I would like you to carry out, that being, with the amplifier connected up in exactly the same way as it has been over the years but "not" powered up, which as you have said, results in all channels being detected, kill the signal whilst viewing any of the channels by powering up the amplifier.
The test being to remove the amplifiers aerial "input" connector and replace it with a short length of wire (3 or 4 feet) pushed into the middle of the aerial input socket, the question being, does this enable a picture of sorts to be seen? By the way, an old (non powered) set top aerial is ideal for this test if its coax connector is removed.
The reason for requesting this test is that I am beginning to suspect that the problem "might" be caused by instability in the amplifiers high gain input stage, (possibly by an electrolytic capacitor having dried out through age) the instability being triggered by the high level signal from the aerial being fed into the amps input stage, high gain stages being far more vulnerable to developing instability problems should anything be amiss component wise.
Purely out of curiosity, are you using a roof mounted aerial? and can you confirm (or not) that your Wolsey uses "F" sockets rather than coax types?
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David Nash: Yes, I would be interested to know the outcome of the "short wire" instead of aerial test, as obviously the signal level being fed into the Wolsey amp from the wire aerial would be a great deal less than from the aerial and I was curious as to whether the amp would still lock up or not, because if it didn't, then an attenuator could be placed in line between the aerial and the amplifiers input.
The undermentioned links are for an SLX 6 way distribution amplifier with built in 4G protection, the second link being for the same amp but with a more detailed specification being given. (by clicking on "specification")
SLx 27823BMG 6 Output Aerial Distribution Amplifier: Amazon.co.uk: TV
Philex Electronic (UK) Ltd. Homepage
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Richard: Although the explanation given by Dave Linsdsay is perfectly correct, insomuch that the present situation is unlikely ever to change, however the fact of Mustards EPG number being seen on your Freeview box indicates that Tacolnestons L-NOR transmitter on Mux C57 was, at the time of scanning, being received at the threshold level for reception.
Although the Thetford area is undeniably well outside of the aforementioned transmitters official coverage area, TX radiation pattern charts are never really that terribly exact, with in many instances reception being possible well outside of the official coverage area for a given transmitter, therefore in order to determine as to whether or not there is any possibility of receiving this programme, that is with any element of reliability! you should carry out a signal test on the channel using the undermentioned procedure.
If the Freeview box you are using offers a "manual" tuning option as well as the standard auto-tuning, select "manual" and enter C57 (762.0 Mhz) but pause at this stage, i.e: do "not" press search or scan, because on most devices (although not all) if any signal is being received from Tacolneston's Mux C57 the level its being received at (no matter how low) will appear on the strength / quality bars, the procedure or "not" pressing search or scan enabling the tuner to act like a form or signal meter free from threshold restriction levels, something which is activated if search / scan is pressed.
Should you find that a signal from C57 is being received but at a very low level, then if the aerial referred to is easily accessible? you could try making slight adjustments to the aerial whilst the box is sitting on the signal check screen, the important aspect of the signal being the indication of "quality" irrespective of strength, (which could be low) and with said quality being reasonably consistent without any undue rapidly occurring fluctuations being seen.
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Dave Lindsay: Yes, quite so, as thats one of the muxes used by myself, but though in my opinion, Walthams COM6 / C57 transmission is extremely unlikely to cause any problems with the reception of Tacolnestons L-NOR channel, that is even although Walthams coverage area chart does indeed indicate an element of patchy coverage being possible in the Thetford area.
However, apart from having a certain personal (on site) knowledge of reception in the Thetford area, even Wolfbane's (or more accurately, ex Wolfbane's) predicted signal level from Walthams C57 is only around 14dB or so.
Of course, that said excludes the possibility of patches of freak reception from Waltham's COM6 due to atmospheric related conditions.
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Bert: Any Freeview TV or box that can still view CBS Action on EPG70 requires retuning, as CBS Action moved to EPG64 on the 19th of this month.
As your posting has been made under the Whitehawk Hill heading, should you reside in the area covered by this transmitter and your TV or box has a "manual" tuning facility, select this then enter and scan C48 and this should correct the problem, CBS Action being being transmitted on Whitehawk Hills COM6 transmitter.
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Caroline Kay: You should try resetting your daughters TV back to its manufacturers (out of the box) settings, this facility being accessed via the menu button, resetting also known as "manufacturers reset" / "default setting" / "first time installation" etc dependant on the brand of the device.
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Trevor Dobie: That said by MikeB with regards to your reception being limited to the Malborough transmitter certainly looks to be the case, a check made via the Megalithia terrain indicator indicating multiple blockages to the signal path between your particular location and the Hannington transmitter, and with any signal that is (if) received when in this type of situation being almost guaranteed to be of an unreliable nature.
However, looking at your posting from another angle, should you be meaning that you are unable to receive any HD transmissions? then what brand model of BT vision box are you using? as some of the slightly older BT boxes (e.g: Vision+) are unable to receive HD transmissions.
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Sunday 22 February 2015 8:02PM
David Nash: Thanks for the info re: distribution amplifier being used. However, there are two versions of this 8 way+1 amp. (1): being a two input model (334038) with each of the 8 UHF outputs having a gain of 11dB, full output being 18dB, and (2): a 1 input model (334044) with each of the 8 wideband outputs being 13dB, full being 23dB.
Irrespective of which model you have, try connecting the feed that runs to the TV into one of the 8 lower gain outputs rather than being connected into full, as this level of amplification (whether 18 or 23db) being used in a location such as yours is (in normal circumstances) grossly excessive.
Of course, I do appreciate the fact of you having been using this set up for 10 years or so, but something has obviously changed, and which I suspect as not necessarily being connected with your installation, but one never knows!
By the way, Wolsey also manufactures another 8 way+1 distribution amp called an "LTE" model, should by any chance you be using this model ? (albeit I doubt that you would be) disregard that previously mentioned regarding 4G, as the LTE model features built in protection against 4G transmitters.