Any impedance/network analyser is going to need a BCB-reject filter in
order to handle that level of interference. However, imperfections in
the filter don't matter with a more advanced VNA such as the N2PK
design, because the filter can be included *inside* the calibration
loop.

GM Ian, Actually, I have used the N2PK under the same conditions that Rick
has and you DON'T need the reject filter. That volt is an aggregate number
and at any 2-3 Hz bandwidth that the VNA detector is looking at, it's at the
uVolt level and not a bother. (Unless you tune TO the BC signal itself of
course!) As for the walk, would probably do most of us some good, but I even
substituted the guy that wanted the measurements made and a pair of $5. FRS
radios for the walk. Works fine if you really want to measure the antenna.
Rick can put the feedline, his transformers and the kitchen sink inside the
cal loop and still measure his antenna if he REALLY wanted to use it.

Used Laptops with a parallel port (And worn out battery) are running 25-50
bucks around here. Had one given to me that Alice plays the cardgame with
using the charger. Most will still hold a charge for an hour or so.

I'm going to be doing a lot of that in the next two years, but the
environmental problems will be slightly different. Where can I find a
laptop with a screen demister and two-speed wipers?

Try a portable igloo, Rain-X doesn't work very well.

Regards
W4ZCB