[BC] Fallout from cuts

[Richard Fry]

> 'dBu' is generally reserved for field strength measurements,
> 'X' db in relationship to 1 micro (u) volt  I think
____________

The FCC and many others refer to electric field strength that way, but the 
correct form really needs to include the basic unit of measure (volt, in 
this case), and the linear distance in space over which that field strength 
exists (most commonly, 1 meter).  So the complete form for units of 
electric field strength is dBµV/m (or dBmV/m, etc).

The terms dBu, dBm etc are used informally even when not intended to 
describe a field strength, such as to state a voltage, current or power at 
some point in a closed circuit.  But to be accurate and unambiguous, the 
basic unit of measure (V, A, W and their variations), needs to be stated, 
or at least well and widely understood.

For example, "dBu" used in this context could mean decibels w.r.t. 1 
microwatt, 1 microvolt, or 1 micro-any other basic unit of measure.  Also 
the impedance across which the value exists needs to be stated/understood.

Details, details...

RF