[evlatests] point on set-and-remember

[Rick Perley]

    Ken reminds me that for set-and-remember to work, it is still 
necessary to stay on source for ~40 seconds for the initial observation 
of any particular frequency tuning. 

    So the '1-db' changes in switched power that I saw in the 'switch 
stress test' on ea14 (and some other antennas) is to be expected. 

    I should repeat the test, but ensure the initial observations have 
longer duration.