In article et, Jim Flanagan
writes:

I have been looking 'high and low' for a copy of the LMO
schematic for the SB line of radios.

It was published in QST when the SB-100 was reviewed. However, note that the
LMO was made by several different manufacturers to Heath's specs and that there
may be significant internal differences. Heath simply specified the dimensions,
connections, tube type and electrical performance, and left the rest up to the
subcontractor. They treated the LMO as a "component", just like the crystal
filters or the power transformer.

Good luck!

73 de Jim, N2EY