Supposed "antenna null" isn't?

Questions
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1

UPDATE: This turned out to be a trivial error on my part. See the response.

I thought that in the far field of a Hertzian dipole the reason there is no E field because the scalar and vector potential contributions to the E field cancel in the far field.

The following notebook seems to indicate that the E field of an antenna “null” isn’t null at all – it doesn’t fall off as 1/r^3 nor even off as 1/r^2. It falls off as 1/r! What’s going on with this ultra-simple calculation based not on an antenna but a simple point charge moving back and forth in a line?

Open in Wolfram Cloud ↗

PS: The comments are a bit off. They should have said the numerator goes as the cube of z and denominator as the fourth power of z.

2

I found the (trivial) problem in my script which is exposed by a couple of things:

  1. The definition of rPrime is inconsistent with the comment, which
    points to the second aspect of the problem,
  2. There is no function
    called “qvr” in the source – although there was one in a prior
    version of the notebook which I’d run, leaving it defined when it
    shouldn’t have been defined.

It would be nice if there were a key mapping to kill and start the local kernel, or which would just execute Quit[] to help avoid this kind of thing.