Dave wrote:
is that line 1 second long, or 1/2 second long?? a 1 second long line would
take 2 seconds worth of energy from the generator before the reflection
returned to let it know the line is terminated. this is of course very
important if you are measuring lines with tdr's where you can really see
those returned waves, of course the time it takes them to get back to the
tdr is double the one-way travel time... mess it up and you are looking for
faults twice as far down the line as you calculate.

The line is 1 second long. The source is generating 100 watts. So the
number of joules generated starting at t=0 is 100N where N is the
total number of seconds. At the end of 30 seconds, the generator will
have sourced 3000 joules which must be conserved.

I will generate an EXCEL spreadsheet at work today and post it to
my web page when I get home. It will cover the first 30 seconds
in 1 second increments. It will show that of the 3000 joules sourced
by the generator during that first 30 seconds, only 2700 joules have
reached the load. The other 300 joules are contained in the 200W
forward wave and 100W reflected wave.

(200 watts)(one second) = 200 joules in the forward wave

(100 watts)(one second) = 100 joules in the reflected wave

200 joules + 100 joules = 300 joules not delivered to the load
--
73, Cecil http://www.qsl.net/w5dxp