You should be able to use the aerial wizard (i think that's that it's called) to look at the signal strengths of the various ensembles that you are able to receive. If you have full scale deflection (high signal strength) then it may be a lack of BBC coverage problem. If they are borderline, then you may have to invest in an external aerial to increase your chances of getting more services. It surprises me that in somewhere like Aberdeen you can't get the services. Do you live in Aberdeen or are you out in the sticks?
You can buy the connector and lead cheap from RS and fashion your own aerial. The stock number for the connector is 326-8445.