Cecil Moore wrote:

If the wave reflects from a short circuit, the voltage reverses
phase by 180 degrees such that Vf+Vr=0. The current does not
reverse phase so If+Ir=2If=2Ir.

Incidentally, this is a different convention from the field
of optics.

Cecil,

That is a rather curious comment. Why do you say the convention is
different for optics? There are no commonly used "voltage" or "current"
descriptions in optics, so analysis is done using E-fields and H-fields.
Otherwise there is no difference in convention between optical and RF.

In any case this reversal or non-reversal is not a "convention". It is
the mathematical result that comes out of a proper solution to the
boundary value problem. The "convention" exists only if one considers
Maxwell equations to be a "convention".

73,
Gene
W4SZ