At one time, Norm's Rotor Repair had an accessible box for the Ham M series.
He's still in business, but I don't know if he still sells that box or not.

I think his web site is rotornorm.com. I always get to it via the L. B.
Cebik asite. There, you will find the link under the "links to commercial
antenna manufacturers" page which is found near the bottom of the "tales and
technicals" page.

The url for Mr. Cebik's wonderful site is

http://www.cebik.com


Mike Duke, K5XU
American Council of Blind Radio Amateurs