Richard Clark wrote:
When I had you thank Bart for his teachings, you should have examined
the consequences of his lesson not simply his correction of your
error.

dB was not mentioned at all in Bart's posting so your comment
appears to be just an ad hominem shot in the dark. My news-
server indicates that Bart has not posted to this thread.

Let me ask my question again.

Given the dB equation for power, 10*log(P1/P2), when we say
the transmission line losses are 1 dB, what is P2 in the
denominator if it is not NET source power? There has to be
a standard. I just am not sure what that standard is. My
question is: What is the standard if not NET source power?

The magnitude of power available for being lost in transmission
line losses certainly cannot exceed the forward power minus the
reflected power, i.e. cannot exceed the NET source power. It seems
to follow that P2 in the equation must necessarily be NET power so
that transmission line losses are a percentage of the total power
available to be lost in transmission line. What am I missing?

In the previous examples, the 5 watt loss in the matched case was
5% of the NET source power of 100w. In the mismatched case, the 5
watt loss was 33% of the NET source power of 15w. It seems to follow
that the line loss in the matched case is about 0.2 dB of the 100w
of power available to be lost while the line loss in the mismatched
case is about 1.2 dB of the 15w of power available to be lost.

I'm still trying to explain the difference between Bob's dB loss
and the ARRL's dB loss. So an obvious question arose: Are they
using the same P2 in the denominator of the dB equation?
--
73, Cecil http://www.qsl.net/w5dxp