[Milsurplus] test equipment question

[telegrapher at att.net]

I have a TS-585C/U output meter.  It doesn't seem to make any difference 
what impedance setting or "multiply by" setting i use, the meter reads 
the same with an audio signal into it.  I'm wondering if this thing is 
not really an audio output meter but something designed to read low 
frequency rf like carrier channels although the large arrangement of 
setting for impedance would suggest it's audio.

Other than hooking it up to the different output impedance's of the 51J 
and the 2.5 ohm point on the AR-88, i've done nothing.  Obviously there 
is no open circuit since the meter does change level readings with a 
change in audio input.  Strange though that changing the impedance 
setting from 600 or whatever down to 4 or even 8 ohms doesn't affect it.

No manual so i don't know if i'm even applying the correct signal or 
not.  maybe something "secret" about using it!

Larry
W0OGH