Anyone else have this problem, a sort of ‘doo-whip’ noise every few seconds as the strobe charges and discharges.
Engineer’s solution (earthing absolutely everything it seems) is time consuming, expensive and he accepts he doesn’t know if it’ll help!
Cheers, Sam.
Replace with LED counterpart. Less power, longer life. And just as ineffective to avoid collision.
I’m afraid the engineer is right. It’s a very common problem and earthing is usually the solution (although often there is no complete solution).
Is it one of those 1970s flash light strobe systems? I have recently switched from standard nav lights to LED nav lights and they produce more noise!
Replace with LED counterpart.
On certified aircraft usually not a legal option. Beacons and nav lights are available STCed for some aircraft under some registrations but strobes not yet.
Earthing everything which has an earth terminal.
Shielding the cables going to the strobe lights, but not running any current through the wire shield, and earthing the shield to the airframe at both ends.
Peter, far be it from me to teach you lessons, but are you sure the noise is radiated from the cables in the form of radio waves? Your suggestions imply so, but it seems unlikely to me. I feel strongly (not hindered by any factual knowledge…) that the noise is mostly produced by the switching power supply required to generate the 200 or so V= that these paleolithic xenon tubes need; and then finds its way into the avionics through the power supply wiring. The shielding you recommend can never do wrong, and solid earth cabling is the first of all anyway; but I feel a couple of LC filters in the supply lines might be more effective. Especially close to the strobe power box.
I agree with you Jan. The strobe whistling (extremely common in GA) is the inverter’s noise, being distributed around the aircraft by conduction and radiation.
I have been doing RF/EMC compliance testing (and bodging) for many years…
It’s a matter of what is the easiest, for the average maintenance shop. I would suggest that rewiring with shielded cable is something any “avionics man” can do. And if that works, fine.
Installing LC filters in the power input to the inverter would be the next thing. Something like this
Getting these with “aviation paperwork” 
is the next challenge.
earthing the shield to the airframe at both ends.
Both ends, really?
Yes; the reason for one end only is a different scenario. Sorry to be brief… packing for going away.
BTW, Socata run the strobe cable (shielded) on the outside of the wing. It lies in the training edge cavity.
