[TenTec] dbm and VU units of audio measurement

[Stuart Rohre]

Ken,
You are thinking of dbmw  dB re one milliwatt; and the VU "Volume Unit" both
of which are usually spec'd across 600 ohm impedance.  VU was used in radio
Broadcast consoles while the dBmw was in the phone company audio trade.  The
VU was damped in a meter having a certain ballistic characteristic, to more
easily judge speech and music levels.
73,
Stuart
K5KVH