Richard; when you say its not working, how are you assessing that? I have just been thru this and by the test required using a 2nd PAW it seemed my funke was not transmiting the ADSB as that wasn't picked up by the 2nd PAW. However, it is working as I flew over my nearest ADSB test airfield (Goodwood) and they confirmed receiving ok, as did solent Radar. So the BMAA put my on to Adrian Garner who has developed a software programme to independantly test the transmission. You can get this via his website at getyourwings.co.uk. I haven't run this yet but hope to do so later this week.
As long as you have set up your funke as per their manual and you have set the correct usb port in your PAW to know its a funke with the 4800 baud rate then saved your funke set up by exiting, switching off. then go into the 'show setup' screens and cycling thru to (I think) the 3rd screen it should show that its getting position info from the gps source. As long as its getting that then it will be transmitting. Do make sure you are using the Farnell usb-rs232 cable and that its wired into the funke rs232 cables corerectly, exactly as per the funke manual.
I'd be interested to hear how you get on. I do have a contact at funke, who is very helpful, if you want it but I doubt you will find its the funke thats the problem.