Oh, Wow! Doug, that technique was never taught at this outpost. But
studying, with crossed eyes, the arc reaching the tip of one's nose was
instructional.
Nope, not me. I did a small amount of radar and HF AM work in the late
50s, early 60s on the Oregon coast, and then spent 20 years in the US
Navy,
retiring as a CTMCS. Did some part time marine work when I was stationed
in
the Aleutians in 70-72 and in Maine 76-84. I have only been into it full
time for about 4 years now, after high tech manufacturing crashed in this
area.
Had an installer come begging for a digital VOM the other day as his went
"over the side". I handed him a Simpson 260. He looked puzzled and asked
what that antique does. He was Air Force trained, so guess that explains
it.
He declined my offer as it was "too complex".

Our main troubleshooting instrument when I was a young mechanic in the Air
Force was the PSM-6. (early '50s to late '70s). In a second life, after Air
Force, Jerry Hamilton, my marine electronics mentor at Whatcom Marine
Electronics in Anacortes wouldn't allow a digital VOM in the shop. He fired
one tech who was addicted to digital and wouldn't do field work without a
scope. (we only had one scope, and it was sorely needed at the swamped
repair bench)
Old Chief Lynn, W7LTQ (ex-Aircraft Maintenance Superintendent)