First Posted 24th October 2010 (Updated 23 March 2016)
- Transmitter Overlaps
Some members like me may have problems with boxes locking to the wrong transmitter and producing unreliable reception. As some of us live between Tacolneston and Sudbury, An attenuator or manual tune may be the answer. The channels will be 62,59,55,50,45,42 On Tacolneston.
Those who live in Bury and use a main transmitter such as Sudbury or Tacolneston may find there equipment locking into the local repeaters. This usually shows as breaking up pictures even though you had a good signal before retuning. The answer is to pull the aerial out until channel 33 is reached or just before the bar reaches half way. Another way is to use a attenuator in the aerial lead while retuning. Receivers that check the signal levels should be OK, but there seems to be a lot of gear that just uses the first signal it finds even if they are weak!! I have seen a number of famous brand TV’s with this issue. I have two set top boxes with the problem.
If you have a problem with Sudbury and Tacolneston an attenuator is the route as the channels are interleaved since switchover.
Just a reminder of the dates…
Sandy Heath 30th March & 13th April 2011
Sudbury 6th July & 20th July 2011
Tacolneston 9th November & 23rd November 2011 TACOLNESTON retune on the 17th of August.
First date BBC2 ceases and is replaced with a high power digital PSB1 mux containing BBC1 and 2. On the second date all analogue TV ceases and the 3 PSB multiplexes go high powered. The 3 Com multiplexes go high powered at Tacolneston straight away, Sudbury and Sandy during 2011-2012 in several stages requiring retuning. You should receive around 14 channels minimum.
After switchover some of the non Public service multiplexes will be out of group for the TV aerial that would have been fitted for analogue. How an aerial responds to these out of band signals depends on the design. The gain will be lower and the side lobes will increase.
Sudbury and Sandy will have channel moves that will be well out of band during 2011/2012. If you wish to receive all the commercial multiplexes a aerial change may be needed, if not wait until the final moves in June 2012 and see how your aerial performs.
You can tell a grouped aerial normally by looking at the coloured bung in the end of the boom.
Ch21 – 37 A Red
Ch35 – 53 B Yellow
Ch48 – 68 C/D Green
Ch35 – 68 E Brown
Ch21 – 68 Wideband Black
If you are using Sudbury and have a group B aerial with a yellow bung at the end you may need to change the aerial for a wideband (black bung) or group E aerial (brown Bung) to receive all the multiplexes. Ch44,41,47 Ch58,60,56
If you are using Sandy Heath with a Group A aerial (Red Bung) you may have to change the aerial to a wideband aerial (black bung) to receive all multiplexes. CH21,24,27 Ch51,52,48
If you are using Tacolneston and have a group C/D aerial (green bung) You will most likely not need to change the aerial as the aerial will respond quite well to the lower frequency’s. Ch55,59,62 Ch42,45,50
Its possible that your receiver may pick up other transmitters that have switched and may tune to that transmitter instead of the one you are using.It depends on the age of the receiver as now changes have been made to freeview specs. Try manual tuning and enter the channel numbers. It may be possible to delete any duplicate channels. You could fit an attenuator during tuning or unplug until the channels you need are reached. One other recommendation to the problem has been in the use of Log periodic aerials as these have a cleaner side lobe and may help to keep unwanted signals out.
You can use any television still to receive Digital (freeview) Some boxes have UHF modulators and can send a signal to any 625 line television, even Black and White! I’ve seen a 1936 set used with a 405 line converter
A VCR can still be used to record from the Digital box as long as you dont mind setting two timers! Pop the channels down on the VCR until it says E1 or AV and you should be recording from the scart. If you wish to record one channel and watch another channel you will need two digital receivers. A DVD recorder or a PVR may be a solution. Some PVR’s allow recording of two channels and watching of a 3rd channel depending on what multiplexes are being recorded.
After 2014 some transmitters that are using channel 61 and 62 will have there channels swapped to 39/40 or other channels. A further retune will be needed! Depending on what the 800MHz channels are used for (likely 4G phone) there is scope for problems with digital television caused by the new equipment causing overload and filters may be needed. Hopefully it wont be a problem! Watch this space :-> Update:- OFCOM are having a consultation about this! They believe some viewers will be unable to filter out the strong in band signals.
Further info. (Links outside our control)
Digital UK. Oversees the switchover
Freeview and Freesat
Useful info and old TV aerial photos.
Some aerials may need replacing.