> >It doesn t matter where the min and max are on the line. The > same amount > >of reflected power will be seen at any point. Reflected > power does NOT get > >back into the transmitter. It gets re-reflected back towards > the antenna > >when it reaches the transmitter circuits. > > I don't buy into this. In order for reflected power to not > be absorbed by > the TX, it would have to appear totally reactive.
Not necessarily true. If there exists a conjugate match at the transmitter, the reflected power will be re-reflected back to the load. The problem, though, is most of our solid state repeater amps may exhibit other problems due to the mis-matched load Z (efficiency drops, PA goes into oscillation, whatever). > This doesn't sound right either, as there should be no > reflected power at > the antenna if it's been matched further down the line. There won't be any reflected power if the matching is done *at the antenna*. If the matching is done at the source end of the line (via a transmatch or similiar device), which is what I believe the topic of discussion was, then there will be reflected power (and likewise VSWR) on the feedline if the load (antenna) Z does not match the cable's characteristic Z. > My guess is that the higher power reading on the wattmeter is > due to the > weird impedances it's seeing on both its input & output. If placed along a length of transmission line that has a VSWR other than 1:1, a directional wattmeter (Bird or similiar) will show the sum of forward+reflected with the slug rotated to the forward direction due to the reflected power being re-reflected at the source end. --- Jeff