All posts by KMJ, Derby
Below are all of KMJ, Derby's postings, with the most recent are at the bottom of the page.
John : To receive the COM muxes you need to be able to receive signals from a main station. In North Devon these are Huntshaw Cross, and in a few favourably placed locations on high ground Caradon Hill. Using Landkey post office as a reference good reception is predicted from Huntshaw Cross at 217 degrees (aprox SW ), the aerial being mounted for horizontal polarisation. If your aerial is pointing to a relay at Barnstaple (NW) or Swimbridge (ESE) with the rods set vertical, you will only be able to receive the PSB muxes.
| link to this comment |
Paul: It sounds like your aerial is pointing to the Freeview transmitter at Hannington. Check that your receiver has, in fact, tuned to the Hannington frequencies (C45, C42, C41, C44, C47 and for HD C39+ if required) It is possible that Rowridge signals coming from behind the aerial have been found when scanning for channels,resulting in these frequencies being stored instead.
| link to this comment |
Vicky: There is no such thing as a "digital" aerial, just an aerial which is suitable for reception of digital transmissions in the location in question. Depending on the transmitter being received it might be necessary to use a different aerial to cover all the frequencies in use if reception of all six muxes is required. Otherwise an aerial that gave good reception on analogue transmissions will be suitable for reception of at least the PSB muxes in most areas. In your particular area if you use the Belmont transmitter you will need a different aerial for reception of ArqA and ArqB muxes. If you give more information with regard to your location, preferably a postcode, a check can be made on predicted reception and further advice given. If your TV does not have a suitable tuner built in you will need to use a Freeview box to receive DTT transmissions, or alternatively a satellite box connected to the dish will receive the free to air satellite channels with no subscription needed.
| link to this comment |
Vicky: The aerial is most likely pointing NW to Belmont, with W to Waltham as the most likely alternative. Check that the cable is continuous from the aerial to the BT vision box, that is, if it goes through the loft the cables have not been left disconnected after a splitter was removed, or the cable does not go to any plastic boxes along its length which could indicate that a powered splitter was in use, the power supply now being absent or turned off. Also, if it is not brand new, did you do a factory reset of the BT vision box to clear the memory of all data before scanning for channels?
| link to this comment |
Terry: After much thought, Ofcom decided that the relay masts which carried four or five analogue public service transmitters would all continue to transmit the PSB services after DSO. Hence the Freeview Lite status for Ivybridge. The licence fee pays for the transmission of the BBC channels; ITV, C4 and channel Five are each required to pay for their share of PSB2 and any use of PSB3.The requirement for the owners of the COM muxes was that coverage should be at least as good after switchover as it had been before. This meant in practice that existing sites were maintained, with a significant power increase on the largest transmitters where the number of extra viewers served justified the additional cost. This places the onus on the viewer to use the correct aerial where a main station overlaps with a relay station and reception of the COM muxes is required. Otherwise satellite reception is often possible in areas not served by a main transmitter. With regard to the Rabbit services, the capacity taken up on the mux by text services is very small, certainly not the amount necessary to support another TV channel such as Film4.
| link to this comment |
William Sutherland: The BBC status report on Mounteagle shows no problem, although if you did lose signal from Mounteagle you could possibly receive the BBC national DAB multiplex from Rumster Forest or Eitshal, whereas the commercial muxes are only available from Mounteagle. If you select channel 11B manually does it show any sign of a signal being present? It might be worth checking that all cables and connectors are in order, including making sure that no strands of the outer braid have strayed and made contact with the inner core.
| link to this comment |
John Brady: If your dish is fitted with a single LNB it sounds like it has changed alignment slightly, as the German channels are carried on the Astra satellites at 19.2 degrees, rather than the 28.2 degree position used by the channels aimed at the UK and Ireland. If you have two LNBs linked by a diseqc switch, you currently have the other LNB selected.
| link to this comment |
Robert: It is possible that you were receiving out of area signals, due to the inversion effect, which were causing interference to your normal reception. If this was the problem it makes sense that the highest aerials were picking up the unwanted signals, but those mounted lower down were possibly shielded from them. Another point worth checking is whether the Oxford frequencies had been tuned in by all receivers. I say this because Mendip is also predicted to be available at your location. As the two transmitters are 180 degrees apart your aerial is likely to pick up both sets of signals. In the case of ITV1 you could have ITV1 West at position 3 in the channel list, with Meridian in the 800s. If Mendip on C54 has been stored the other channels on D3+4 from Mendip are likely to be in the LCN (normal) positions of the channel list. In the case of the SDN mux for 5* and 5USA, if C48 from Mendip was stored, the Oxford signal on C62 could have been ignored completely.
| link to this comment |
Sunday 12 August 2012 5:22PM
Ian: If you are using the Chesterfield transmitter (aerial set for vertical polarisation, pointing North to Unstone) there is the posibility of interference on every mux, due to frequency clashes. The COM muxes share frequencies with the PSBs from Sutton Coldfield, the HD mux shares with SDN from Waltham and PSB1&2 from Chesterfield use frequencies which are also allocated to Bilsdale, resulting in possible interference when conditions are such that the Bilsdale signals are present at a higher than normal level. Your best prediction for reception of all six muxes from a single site is Emley Moor, aerial pointing NNW and set for horizontal polarisation. The prediction is of course subject to there being no local obstructions (trees or tall buildings) obstructing the signal path.