I took the General Radiotelephone Operator's License exam in 1981, just
after it went into effect. However, they were still giving the old 2nd
class
exam, which was mostly about tube technology and which shared nothing in
common with the Extra Class amateur exam of the time.

I did 2nd Phone in the late 70's and there was tube, transistor, RTL and TTL
logic theory, and 'complete the schematic' type questions but less of that
and more general types of engineering and circuit theory, AC/DC theory, RF
and transmission lines and most of it involving Electronic Math. Trig,
Vectors, no Smith charts or Calculus. Very little of it had anything to do
with tubes specifically. The rest was FCC parts. It was said at the time,
that it was more like the Advanced Ham ticket. I got my Advanced a year or
two before, and I agree the technology level was equivalent and it was about
200 questions or so. Later when I did the Extra, (90's) there were
questions well beyond the 2nd Phone but only 25 of them! The code test and
the noise floor equations made me strain. I wish the bandwidth and
modulation questions were on the Technician class test though.