Thanks, Wes. And in case anyone missed it, since the input impedance
goes to infinity, you're delivering no power to the input, so there is
no voltage across the load. The transmission is a comb of notches,
spaced in frequency by (speed of light)*(v.f.)/(total length of line)
-- in this case, 3.2296MHz as Wes says. In other words, the first
notch and the notch spacing is equal to the frequency at which the
total line length is one wavelength. If the difference between the two
line sections is small and they have loss, the notch is not very deep.
If you could actually get lossless line, it's a way to make very
narrow, very deep notches, but then if you could get lossless line, you
could probably also get lossless capacitors and inductors and make
deep, narrow notches with them.

On the other hand, if you have a wavelength of line connected in a loop
and put a load 1/4 wave from a source (which is 3/4 wave around the
other direction), you get quite a good notch even if the line is
slightly lossy. Look up "hybrid junctions" for more info.

Cheers,
Tom