On Sat, Mar 26, 2022 at 10:22 AM Harvey White <madyn@...>
wrote:
As others have said, the readout works in two modes. The beam (a single
one) is always shared. The readout circuitry can either wait for a
retrace (useful for high sweep speeds), or chop the beam at a given
rate. Chopping the beam produces those little blanks in the trace. A
little extra switching would have fixed that, but instead, Tek used a
slide switch on the readout board so you could pick the most convenient
setting. That's the "dual mode" I was talking about.
I've been through the readout schematics in a fair amount of detail before,
but I don't remember seeing a switch anywhere. I went back to look at the
readout schematics just now, and I still can't find a switch. Is it
possible you're confusing the 2465B with some other readout implementation?
According to the Theory of Operation, the 2465en have fairly elaborate
machinery that strives to maintain a flicker-free, uniform brightness
readout, no matter the sweep speed or trigger frequency.
