419 Langsett Rd
Hillsborough
Sheffield
S6 2LL
© 2010 Justin Smith A.T.V
All Rights reserved
Transmitter Channel Allocations
The frequencies given are for the analogue channels, for (most) digital MUXES add 3Mhz.
We are in the process of adding Channel Allocation Guides for all the main transmitters on this site (e.g. Crystal Palace) but because the coverage areas of most main transmitters are so large they do not represent the receivable frequencies in a particular geographical area in the same way that this one does.
This tables below list the broadcast channels for all the receivable TV transmitters around Sheffield both before and after the DSO. On the “Post DSO” guide note the gaps in the spectrum on channels 31 to 35, 37, 39 to 40 and 63 to 68.
These are reserved for “other uses”, i.e. selling off the frequencies........
Apart from the guides obvious interest to those in this area it serves as a graphical reminder just how crowded the RF (Radio Frequency) spectrum is, note how the planners have “dovetailed” the various broadcast frequencies together in an attempt to minimise
co-channel interference. Clicking on the latter link will also give some advice on how to combat the problem.
For more evidence of just how crowded the RF spectrum is see the frequency tables
on the Aerial Tests page.
The various Channel Allocation Guides can 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-channel.
Also see map of approximate coverage areas for all the UK TV frequencies. This reference is interesting but (as with all coverage maps) it can be misleading, see “Line Of Sight”.
These particular maps also seem to lack many of the outputs from the smaller repeaters and the restricted radiation patterns of some of the transmitters do not appear.
So all of this should be borne in mind when using them !
The five transmitters on the right hand side are all small repeaters with relatively small outputs and coverage patterns, thus the potential for co-channel between them is (theoretically....) small.The “post DSO” frequecies are to be confirmed.
One must remember that Sheffield is a hilly city (the resultant rivers, in the low lying areas, helping to explain why the steel making industry developed here) and so there are
relatively few locations where more than one or two of the small repeater transmitters
would be co-receivable.
On the 17th of March 2010 MUX1 off Sheffield/Crosspool transmitter moved from CH39 to CH63. This change was to prevent co-channel interference with the new temporary low power HD MUX to be transmitted from Emley Moor on CH63.
One problem is that many people who used to be able to get MUX1 off an
A group aerial will probably cease to do so, though its transmission power is due to be increased to its much higher post DSO level, i.e. from 100W to 1kW.
Furthermore there are a lot of Sky boxes and Videos which have their RF output set on CH63 so this will then require moving in order to prevent co-channel interference.
Above is the Channel Allocation Guide for the Sheffield area “pre DSO” and below
is the proposed “post DSO” version.
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”....