Distance from mast to upper backstay insulator

[afmstm]

Hi all,

I will be installing an antenna insulator in a shroud (instead of backstay) and would like advice on the minimum distance between the upper end of the insulator and the tang. Is there a compelling reason not to use an insulator with an eye on one end that attaches directly to the tang? The tang is about 1 foot from the top of the mast.

I'll be attaching the feeder to the chainplate directly, with the tuner under that. Also insulating the shroud from the spreader with a spreader end fitting made of acetal or fiberglass.

This will give me about 35 - 36 feet of antenna. Since this is a ketch, I'll then run a wire from the main masthead to the mizzen, sort of an inverted L design.

Thanks

Van