[Al (astral highway)]

Hello David,

Thank you so much for your thoughtful reply, full of useful pointers.

FR4 does seem to be ideal - I am familiar with it as a substrate but it hadn’t occurred to me as a candidate.

Your sketch is correct and the reason for the two halves is simply so I can mount it around existing windings with protruding, inflexible tapping points. It isn’t beyond me to cut it in half myself, however.

I have back-up ideas for the corona guard but this is the best looking solution!

Thanks again for taking the time to bring such a detailed response,