I'm looking for one of the 60cm G3RUH dishes

Got one, (but not available).

Questions: I measured reflector grid separation as .88 inches which works out to be about 0.18 wavelength. I always thought the grid had to be tighter than 0.1 inches to be an effective "surface".

Maybe the difference with almost double the spacing is not that significant? (especially for a steel one which would be quite heavy.

Reason I am asking is that I also need another S band dish (at 70 MPH on the roof of a tracking van) and we are thinking about building one by using an old solid 6' TVRO dish as a form and laying in copper wire and soldering it to copper straps. With all that labor, I'd not want to get the spacing wrong.

Bob, Wb4APR