Thanks Chris, I'll report back when I have a definite answer but there are several unknowns at the moment including a new antenna and the fact I have to use Linux for decoding - an operating system completely foreign to me.
I have a cased version of your bias tee, what is the maximum usable frequency I can use it at, I want to power a L band LNA (1.6GHz) - would your bias tee be ok at that frequency?