I have bought various aerials from Maplins, all seem to do a reasonable job - and depending on the scanner being used of course. I have a Yupi MVT7100 and Uniden Bearcat 3500XLT. Both work very well for reasonable priced sets. Yupi also picks up HF from Shanwick Oceanic etc. using a simple long wire aerial in garage roof.
One aerial has 4 x varying length aerials combined in one unit, works very well mounted high up inside my garage. Another is telescopic, and for airband works best extended to about 18-24 inches.
Heathrow Director:
From a 2nd floor flat in West London I can pick up Heathrow Ground controllers only on AM, but switching to VHF around 455 mhz I clearly hear both controller and aircraft taxying around, stand info, takeoff clearance etc. Any idea why this shoud be? Do they actually transmit on 455mhz ... or is it some sort of signal "echo" from the AM frequncy?
( - and keeping in mind the legal aspects of all this as usual).