Thanks for the info. What is the unique zero beating technique they use? Does it come with narrow CW and/or SSB filters, or is it even possible to find narrow filters for it today? I get the impression that there wasn't a lot of these radios sold in the US. Do you know who made them for Hy-Gain?
73 John AF5CC
Given that many radios of that era treated CW as an afterthought, the Hy Gain performs very well.
When you find a station to work, you throw the CW CAL switch and zerobeat the station. Then turn off the switch and you will hear him at 800Hz and your TX will be spot on. No RIT needed, but can be used of course.
While CW uses the SSB filter it also uses a narrow audio filter. While not as ideal from an AGC standpoint- the filter is well shaped and makes CW a joy.
My understanding is that the rig was designed at Hy-Gain and about 200 were manufactured by Panasonic/National.