Well given how little information you've given, we must consider the blindingly obvious:
What frequencies have you tried? (165-168.3 and 453-454.0 and 456-457.0 are prime bands to try)
Is the volume turned up? (it happens)
Is the squelch turned down? (ditto)
What antenna are you using?
Try these ATC freqs, all transmitted from Daventry (probably):
121.025
127.1
127.875
128.6 Volmet
129.2
Kettering BC 166.15 & 165.75
165.0625 prob a Taxi co
165.525 MHz Tranex Telecoms
454.05 Kettering Hosp paging
455.575 Kettering Hospital NHS trust
460.025 APCOA parking enforcers (boo hiss)
453.025 453.8 453.9875 Morrisons (must be a distribution depot?)
453.55 East Midlands Trains
453.175 453.925 Wincanton
Find more local businesses at
http://spectruminfo.ofcom.org.uk/spectrumInfo/licences (Leave "Simple UK" freqs out of any search cos OFCOM haven't got the sense to do that for you)
Business "Simple UK" freqs:
http://licensing.ofcom.org.uk/binaries/ ... empla1.pdf