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