The personal transponders seem a lot less hassle BUT THEY'RE SO EXPENSIVE. I think I was told AMB is the right one to get. Is MRT ok also? Apex do them for £60
http://www.apexmodels.com/gbu0-prodshow/MRT-PTX-20.html
Is this the best deal? Is it too risky to buy a second hand one? They seem to go for at least £40 on eBay so it's not much of a saving.
Any advice welcome. Thanks.