True enough about S-meters historically being a relative indication.
There
was a time in late 50's and early 60's when the "S-meter wars" started
between the manufacturers, mostly Hallicrafters and Hammerlund. On each
successive model, they boosted the sensitivity so that if you did a
side-by-side comparison, the radio showing the highest reading would be
thought to be superior. The strategy worked for a while, until everybody
got
wise!
I think that was about the time that the S-9 = uV, and 6 dB per S-unit
standard got popular, and Collins stuck to it pretty rigorously. They are
still known as having "Scotch" (as in 'tight-fisted') meters.
Obviously readings are relative since a receiver hooked to a dipole at 10'
will read far less than one connected to a 6 over 6 over 6 array on a 180'
tower. The benefit of accurately calibrated meters are to help in antenna
comparisons, getting a "ball-park" on F/B ratios, relative conditions
between stations that talk on a regular basis (I do that on 75 all the
time), comparing two stations in nearby locations, etc. Both my KWM-380
and
my TS-870 have S-meters that are remarkably accurate, although I
determined
that the '380 uses a 5-dB/S-unit standard instead of 6. The 870 has a
menu-selectable option that automatically changes the S-meter reading to
compensate for the preamp.
It would be nice to have readings that correlate to a known standard in
the
Orion.
Ron
N6AHA