On 10/6/2015 6:31 AM, Jeff wrote:

The whole function of the ATU is to provide a 1:1 match for the Tx, when
that is the case NO POWER GOES BACK TO THE TX.

That is not technically correct. A 1:1 match prevents TX power from
being reflected, it does not prevent other power from being sent to
the TX.

Depends how pedantic you are being, we are only considering the wave
that is originated by the Transmitter at one particular frequency. If
the ATU is set to provide a 1:1 match at that frequency then NO PART of
that forward wave will find its way back to the Tx.

Who is being pedantic? It is not about the reflection of the power from
the TX at that point. The issue being discussed is how much power
reflected from the antenna will find it way back through the ATU to the TX.

Just as all power from the TX will cross the 1:1 impedance match (if
there *is* a 1:1 impedance match) all the power passing through the ATU
from the antenna will find it's way into the receiver. The question at
this point is if there is *any* power that is not reflected by the ATU
*back* to the antenna to pass through the ATU.


That is not to say that
....snip without changing meaning...
a signal that originates at the antenna will
not pass to the Rx.

That is my point.


Anyway this discussion has now got to the silly stage so I am off.

Ok, enjoy.

--

Rick