Could some please point me to a good explanation of  how litz wire works?

I realize that it is more efficient at LF because of the larger surface area
but I am trying to understand the relationship between "Q"  DC losses in
antenna,  AC losses, and radiated power.

In the RSGB LF Handbook  I see mention of coils of between 1000 and 3000
I believe this was in referece to loading coils

Thank you

Paul
W1VLF