I picked up a Dovetron at the Shelby hamfest - it has a TSR-300D card that includes regen plus SELCAL - it isn't clear what all the switches do, so if anyone has instructions, that would be very helpful.

There is info on line covering the TSR-200D and TSR-500D but this variant is somewhat different.

This document has a brief description of the various TSR models including page 33 on the 300D.

best regards,