Thermion wrote:
Can anyone please explain the difference(s) if any, between
the two Heathkit "Sixer" models HW-29 and HW-29A?

The HW-29A used 8-MHz crystals for the transmitter, and multiplied the
oscillator frequency by 6 (so that 8.333 MHz crystals transmitted on 50
MHz) -- the 8 MHz crystals were readily available surplus at that time.
The earlier HW-29 which came out around 1960 used more-expensive
_overtone_ crystals -- in which the crystal was actually made to operate
at a multiple of it's basic frequency. Since the 8 MHz FT-243 crystals
were so cheap, many, if not all, the HW-29s were modified to take them,
and Heath quickly figured it out.

Northe
N6KO