[evlatests] WIDAR-0: short scans show phase jumps at X band

[Michael Rupen]

We took two WIDAR-0 data sets yesterday afternoon (15jun09) to check 
a software change, and to see whether short scans lead to phase jumps at
both X and C bands.

Data sets:
- 3C84 or 3C273 or both
- IF 1A (RCP)
- one run entirely X, one run entirely C band, each ~30mins long
- 20sec scans, 1 sec dumps
- two subbands (subbands 1 & 2)

Results of a very quick look:
* No fringes for ant. 25 at C band, nor for ant. 3 at X band.
   - Note that antenna 25 was moved to N2 yesterday.  Antenna 3
     is on the east arm and has not been moved recently.

* Both X and C bands show phase jumps at roughly the same rate
   (3 jumps at X and 2 at C band).
   - The antenna groups are the same at both bands:
      1  3  9 23 28
      2 18 19 24 25
     This confirms the earlier observation that the phase jumps track
     slot number rather than antenna.

* POSSM at a random time shows that the two subbands connect very
   nicely in both phase and amplitude, suggesting that Bruce's new
   flipper code has not destroyed anything.

         -- Michael