Thank you David and VA3RR for your comments.?
I found??to be quite helpful but it raises the question : When a schematic reads "4mm Air Core" does this mean 4mm from wire center to wire center ( taking into consideration the wire diameter as per the above calculator ) -or- the ID of the coil ( as in what drill size to use to wrap the coil around ) .? I suspect that VA3RR's comment that it does not matter much , but with a larger wire, large overall diameter and multi-turn , it might.
And here I am picking nits again.
Thanks to all.
Committing to solder.
Al
K7AOZ
