Hillsborough
Sheffield
S6 2LL
All Rights reserved
Sudbury Transmitter (& Sudbury B) OS Grid Ref TL 912 376
Note As work takes place on various digital transmitters (to prepare for the DSO)
you may experience problems, e.g. with certain MUXES disappearing.
First try rescanning your set top box and if this fails to work check on Transmitter work
or phone reception advice on 08700 100 123 (BBC) or 0844 881 4150 (ITV).
Sudbury was opened in 1968 for the transmission of BBC2 and then BBC1/ITV were added in 1970, finally Channel 4 came along in 1982. It is horizontally polarised and was originally a B group before the advent of Digital / Freeview, though most of the latter is still within the same group. Analogue power is 250Kw apart from C5 which is only 50kW, for
Digital power see the accompanying table.
There are a few out of group issues, MUX 5 is on CH54 though this is only one channel above the band so would be receivable on all B group aerials. MUX 2 off Sudbury is on
CH68 and would not normally be receivable off a B unless you were in a very strong signal area. The supplementary transmitter, "Sudbury B", (which is mounted amongst the other Digital arrays) only transmits MUX2 and this is on CH56 which is just where most
B groups response falls off, though reception would usually be fine in reasonable signal areas. Thus Sudbury is now an E group.
The figures for the mast heights vary according to which source you look at, but I reckon
the mast height for the original TX is about 140m (a.g.l) with the aerial array (covered by
its fibreglass shroud) on top of that, possibly another 20m. The second of the structures,
the one transmitting digital, is around 130m in height. The site height is 70m and is located 14 miles WSW of Ipswich. Sudbury`s approximate population coverage is just under one and a half million and it has five small repeater transmitters off it.
Sudbury/Sudbury B have quite complex radiation patterns (see accompanying table and
the picture of the transmitting arrays) and it`s always worth considering another transmitter
if you are experiencing problems with reception from it, see co-
Co-
CH39 (MUX4) is co-
CH48 (MUX3) is co-
CH49 (MUX1) is co-
CH50 (MUX6) is co-
CH54 (MUX5) is co-
CH56 (MUX2 B) is co-
CH68 (MUX2) is co-
Plus co-
For Sudbury`s TV Channels / Frequencies see its Channel Allocations for before and
after the DSO. These also include the same information for other potentially co-
Hertford, Hemel Hempstead, Oxford, Sandy, Waltham, Belmont and Tacolneston.
The Channel Allocation Guides can also be invaluable if you are trying to find a spare channel for a modulated output (e.g. for a Sky box or CCTV system) to be added to your
TV setup/distribution system without suffering from co-
Sudbury is due to remain an E group (or wideband) after DSO in June 2011,
though the 3 PSBs will still be within the original B group, see Sudbury`s graph.
MUXES 4 to 6 will be out of band though may be receivable in strong signal areas, particularly MUX4 on CH56.
Sudbury B will cease to transmit.
The transmitter is about 2 miles East of the railway line from Marks Tey to Sudbury and
this was opened in 1849. Sudbury station has an interesting history as it was originally situated about 200yds further NW into Sudbury, but was moved when the line to Haverhill/Cambridge was opened by the Great Eastern Railway in 1865. Sadly this later addition closed in 1967.
Sudbury Transmitters from the South. The original Sudbury transmitter is on the right and the Sudbury digital transmitter on the left. (All pictures Justin Smith ATV)
Ahhh, so they are different heights ! Sudbury`s two masts from a point exactly equidistant from both of them. The fact they`re bending inwards is obviously down to the wide angle
lens, not some new fangled engineering technology. The fact the picture is of low quality was down to the lighting conditions, but I`m not going all the way back just for one photo !
Above left we have Sudbury`s transmitting antennas from the West, and above right a
picture taken from the East, see close up of the latter below left.
Published Sudbury aerial heights
Analogue 1 to 4 = 136m
Analogue C5 = 96m
Digital = 118m
Digital (B) = 104m
a = analogue 1 to 4
b = analogue C5
c = digital (apart from MUX2 on CH68)
d = digital MUX2 on CH68
Study of the pictures will reveal that transmitters b and d cannot be omni-
Going by Ofcoms radiation pattern info it follows
that d would be for MUX2 (on CH68) and it is also
at approximately the right height, given that the mast`s total height is around 130m and the transmitting array should be at about 94m.
Transmitter b should be analogue C5 for which the aerial height is about 96m on a total mast height of 160m. I am particularly keen to confirm the radiation pattern for analogue C5 because the arrogant b******s wouldn`t tell me what it was, so I`d love to get hold of this info and put it on the site, just to “stub them out” (as we used to say at school) !
Any one know ? If so please contact us. I`d have thought that b must be attenuated to the SW due
to its position on the mast. Also analogue C5 is on CH35 which is co-
is WSW) and Waltham C5, which is WNW. Furthermore there are two C5 repeaters W / SW
of Sudbury, Chelmsford on CH63 and Cambridge Madingley on CH34. If Sudbury C5 wasn`t attenuated to the SW why would these be
required ?
Close up of Sudbury`s digital transmitting array from the East. Note that the MUX2 transmitter is “round the other side”.
Sudbury television transmitters frequencies/channels for before the DSO (above) and
for after it (below)
Also check Sudbury`s five small repeater transmitters.
Note the gaps in the table below for channels 31 to 35, 37, 39 to 40 and 63 to 68, they`re reserved for “other uses”....
Sudbury`s channels in relation to the UHF TV band and the gain curves of the aerials
we recommend for it. DM Log Log40 Yagi18E XB10WB XB16WB
Note the gain plot of the original B group of the transmitter and how certain MUXES are
(and will also be so after DSO in 2011) out of band.
We recommend the DM log aerial for strong signal areas, the Log 40 for medium signal
areas, the Yagi18E or the XB10WB for poor signal areas, and the XB16WB for
those with the most marginal signals. See Sudbury`s Graph.
The dimensions and test performance of the antennas can be found on the relevant tables. The prices of the aerials are on the Sales page.