[evlatests] S-band 'OSRO' default frequencies

[Rick Perley]

    It's a bit late in the game, but ...

    I believe the default frequencies for S-band OSRO-style observing 
are 3.082 and 3210 MHz (center).   The latter is a bad choice, as it 
contains the *very strong* internal 3200 MHz birdie.  We should migrate 
away from these, either below or above.