I also see flicker on my novatacs, in a couple of different battery conditions
Ive seen flicker pretty consistently when the battery is at about 3.6v. I take that as a low battery warning… If I just draw the cell down a little, for example by using maximum for a moment, that trigger voltage passes, and the flicker goes away. I speculate the flicker is due to the step down circuit being triggered, but happens when the light is on less than maximum.
I also have seen flicker on the lowest mode, usually when the battery goes below 3v. I again take that as a low voltage warning.
And, we know that HDS lights had a flicker issue with the lowest modes, and that is why Henry set them to about level 5, of 0.33 lumens
Despite all that, I still really enjoy the basic 4 mode clicky design of the HDS UI. The tight throwy beam is very efficient. Much brighter in Lux, than the Lumens would suggest.
afaik the First Gen Novas with serial numbers starting with 1xxxx were built in Tucson… I believe Hogo worked for Novatac at that time, And that is how he met Henry, who it seems was still involved… That is also where all the calibration tools were. Henry lives in Tucson, still.