There's one M to Q adapter shown here:
Size-3063 "RS size Q" Coaxial Power plugs have 6.3MM=.250" O.D. with 3MM hole
CR30-346 Coaxial Size Adapter size-2155 socket = jack to size-3063 plug $3,20
Size-2155 "RS size M" Coaxial Power Plugs have 2.1mm hole & 5.5MM =.216" O.D.
the hole in a Size-2155 connector is close to the size of a 5/64" drill bit
[This message has been edited by spark1 (edited 04-05-2011).]