YIKES!!! That could easily lead to death by revealing your susceptibility to heart stoppage by the AC mains.wpaulvogel wrote: ↑Mon Dec 04, 2023 11:56 pm It’s a lot more revealing to put 100-120 volts on the primary and measure the secondary than such a low voltage like 12 volts.
The vast majority of readers on this forum have no training and little if any experience in dealing with AC mains voltages, other than soldering the AC mains wires to fuse, switch and power transformer. And an even vaster majority do not have any source of 100-120VAC other than cobbling up a connection to the AC wall socket. A direct use of the AC wall voltage makes the entire planet the other side of deadly voltage connection.
The likeliest scenario for an inexperienced someone trying to use 120Vac mains to test an OT is to hack-wire a line cord directly into the primary of the OT or to bridge the AC wires on an amp chassis to the OT primary - possibly on something like clip leads or lengths of hookup wire.
At a minimum, an isolation transformer is needed to make using mains voltages less deadly. I have an isolation transformer but I would be mildly astounded if there were more than a dozen forum readers (including especially guests) that have access to one.
I think that we need to point out to the unseen beginners and guests where there are likely to be unexpected deadly traps.