[Heathkit] SB-102/SB-640 LMO problem

[Van K7VS]

Has anyone had any experience mating the sb-102 and sb-640 unit?  Think 
there is a problem with the bias i.e  The sb-101 uses a tube type lmo and 
the 102 the transistor lmo with major bias differences between the two which 
effects the shift from upper to lower sideband on the sb-640 which uses the 
tube type lmo so they won't track at all from lsb to usb.  Was there a "fix" 
for this??  Thanks in advance.  Van, K7VS