[evlatests] Pulsed RFI at x-band

[Rick Perley]

    In general, X-band is very clean.  But an interesting pulsed 
emission is seen between 9335 and 9243 MHz.  The pulses are on all 
baselines (hence, external in origin), are seen in both polarizations 
(no surprise, given they come in through the sidelobes) and have a 
4-second period.  They are restricted to a few (3 or 4) unique 
frequencies.  They are not very strong, and should be very easy to 
excise from the data through an 'RFLG' type algorithm.