Roy Lewallen wrote:
50 watts is entering the line, and 25 watts is exiting. The line loss is
3 dB. Surely you're able to make this calculation yourself.

Surely you can appreciate the potential for one person to use the
signal generator output power as the reference for the dB loss
in the transmission line while another person may, as you do,
reference the line losses to the difference between the signal
generator output power and the power being dissipated in the
circulator load.

I suspect Bob and the ARRL are using different reference powers
in their calculations. My technician at Intel would have reported
the 25 watts of feedline loss above referenced to the signal
generator output power of 100 watts as was customary.

I don't feel a need for a definition of a "power ratio". What you've
defined is indeed the ratio of two powers, but it escapes me of what use
it is except perhaps to cause confusion.

Huh???? A "power ratio" is the *DEFINITION* of dB as applied to power.
Talking about dB is meaningless unless the two powers are defined.

A direct quote from _Reference_Data_For_Radio_Engineers_

"By *definition*, number of dB = 10*log(P1/P2)"

4th edition, page 40
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73, Cecil http://www.qsl.net/w5dxp