[BC] dbu to microvolts program

[Richard Fry]

Peter Moncure wrote:
>Perhaps part of the confusion is the omission of the /M part
>of dB?, which is usually dB?/M, or decibels above a microvolt
> per meter (and) ...their term should also be dBW/M.

Agree, but to eliminate even more confusion the correct abbreviation for 
meter should be used, which is m, not M.  In standard SI units, "/M" means 
"per mega" -- which tends to be rather confusing :)

>So dB? to dBm conversions have a frequency term.

True, if expecting the reader to know that dBu means/describes a voltage 
field strength, and that dBm refers to a power produced by that field in a 
given impedance when an given antenna system is immersed in that field. 
However a voltage field strength can be converted to the radiated power 
density needed to produce it irrespective of frequency.

Really, the term "dBu" is incomplete if using proper SI unit designations. 
If it is a voltage field, then the unit of measure is in multiples of one 
volt, and needs to include the distance in space over which that voltage 
exists.  So an accurate form would be dB?V/m.  Likewise dBm is 
incomplete -- it should be dBmW, using the conventional assumption for the 
meaning of dBm.

The incomplete form dB? could be dB?W, and dBm could be dBmV
or even dBmV/m, so probably it is better to write out the complete units.

Nit-pickily yours,

RF