**UPDATE** - on Voldemort's blog he tested the E11 and found "Significant RF leakage from DC-DC converter into output" - this may be the cause of the static bursts after all. Anyway - next trip overseas, I'm going to see what else is around. Most of the time it doesn't bother me - but sometimes (particularly with IEMs) it gets annoying.
**UPDATE 19 March** - static either worsening, or maybe I'm just noticing it more. In any event - I can no longer recommend the E11. Static / noise now very annoying. I've stopped using it. Shopping for something else now ..... **
Turns out it can't be RF leakage from the DC-DC converter - as the frequency would be inaudible (96Mhz). So I'm stumped as to what causes the weird static bursts. In the end I gave the unit away.