[lesparapluies]

Thanks for the advice, will check out all of that. Now the next question may be a bit like asking how long's a piece of string but here goes: I don't have a signal generator but I've been thinking about investing in one for a while. I built myself a simple injector / tracer for fault finding in amplifiers, but it's just a straightforward single audio tone, so I need something much better for radios. What kind of spec. should I thinking of, bearing in mind it's unlikely I'll ever use it for anything other than this level of work (i.e. no TV stuff) - and it is just a hobby?