.
This has to be one of the simplest adaptions you could do. This radio is programmed to have 10 blocks of 40 channels which include the
UK40, Splits and -11ch dropper. All you need to do is remove the case and make sure the power is completely disconnected from the radio,
then with a hot soldering iron and desoldering pump remove a solder link. Thats It !!  How easy is that.... leave the radio for 5 mins then
connect up the power and you will be away.
This works on the Cobra UK25 LTD ST and UK29 LTD ST. On the 29 the blocks are controlled by the tone and delta tune controls, on the 25 I
believe it to be the tone and the dimmer.

They say a picture is worth a thousand words so see below where the solder link is... click for a larger view...
Click to enlarge
NB. If the adaption doesn't appear to work disconnect the radio completely from the power supply for longer
CHANNEL CHART FOR COBRA UK25 LTD ST

CHANNEL CHART FOR COBRA UK29 LTD ST
RIGHT CLICK AND "SAVE AS". WITHOUT THESE CHARTS FINDING THE CHANNELS WILL BE EXTREMELY DIFFICULT
CB Radio History from its early days
CB Radio Repairers in the UK
.