Jim Hackett wrote:

Mine is an "A" model. It has a clock. Does yours?

The "A" designation has nothing to do with the clock. With the "A" model of the
HQ-170 and the HQ-180 the hfo/mix1 were on all the time and whatever other
improvements were made.

Typically the "C" denoted a clock, which may have been optional on earlier
models.

dxAce
Michigan
USA