Robotic lawnmower interference?

[Benedict.Smith]

Are there any measurements I can do to see how large and what kind of interference my Husqvarna mower produces? I have a cheapish oscilloscope and a nice multimeter...

Hook your scope up to the output of the amplifier board, then try different positions for the antennae till you minimise the signal from the lawnmower.
The lawnmower signal should show up very easily on your scope.
If you don't have a Blitzortung system yet then just build a loop antennae and connect that to the scope set to its most sensitive input, you may get better results with a small signal diode in series with the loop, this should work close to the lawnmower system.
Ben.