Very illuminating! Extra special kudos for salvaging and maintaining all that old but great equipment. I am impressed with the low distortion exhibited by the oldest one out of the lot: has it been restored in any way? I'd expect with component aging it would have various issues. Also, is the battery oscillator's higher distortion possibly due to similarly aging components going out of spec, in your opinion, or could it be due to the restrictions that the low battery supply voltage places on the circuit design? Most impressive of all is that the distortion analyser still works great! : )

Thanks I just got an earlier 330B thanks for the video.

exactly the right beard for the job

Great stuff! 👍

Very good demo, short and to the point. I like that. Too many of these tutorials are full of fluff (BS). Thanks!