All in the ear of the beholder.
I started out with a johnson valiant. I tuned the transmitter by pressing
my ear to the metal case, and listening for the dip in hum. I tuned the
grid by listening to the click of the meter needle. Later I counted the
dial turns on the drake radios. Since each turn was 25 khz, you could get
with in 2 khz or so quite easilly. I have wondered if a neon light coupled
to a feed line could be read by an audible light probe. How good would
maximum brightness be? Interesting experiment. Then in the late 80's I
bought a triton 4 and found the speech box that tentec made for it. I
thought I had died and gone to heaven.
I have an Omni D and still have that box. That's a backup radio.
We've come a long way.
H T Kaufman MSW LCSW
Adaptive Technology Instructor