No, I didn't - I tested the DAB radio by using one of the TV antenna connections to tune it in as with no connection it did throw an open circuit error on the antenna.
Thinking about it, this may be a way of testing the DAB antenna - if you have a TV, then you could plug one of the TV leads onto the DAB output of the amp (you'll need to take the FAKRA housing off I suspect) and there is a VCDS test that displays the antenna info on the TV screen so should show if one of them is very low..I'll see if I can find the info
EDIT:
This was the article where I read about the diagnostic info:
http://a6retrofit.tripod.com/article...5hybridtv.html
near the bottom it says
Interestingly, if you have the TV tuner selected when fiddling with the 57 TV Tuner box via VAG COM, the TV Tuner video will show all kinds of diagnostics information, like antenna reception values and temperature
I do remember doing this myself when I put the digital TV in - hope this helps