Singal injected the preamp with a 1mV @ 100mHz signal, measured the output directly from the preamp and verified the voltage output. Verified ADC signal read back on the expert control screen (see fig. 2 and 3).
Cycled harp, recorded the harp scan (see fig.1).
*During the troubleshooting process, I was measuring -5.0 VDC on the preamp output. After disconnecting the signal cable from the harp to the preamp and then reconnecting them, the negative voltage disappeared.
Very quickly tried to look for noise on Hall B beam in the Injctor Service Building. Nominal B beam was on to FC2 and looking at BPM 0I02. Figure one shows the setup. It seems there is motion on the beam at 11 kHz (Figure 2). Zooming in, Figures 3 and 4 show two peaks at 10.46 and 10.78 kHz. No such noise on 1I02 - Figure 5.
Once Yan is done steering the injector, will check again for noise on Hall B beam.
Once the injector setup is done today we will need to verify the parity quality. We have an online "live" screen for this setup at: https://hallaweb.jlab.org/parity/prex/onlinePlots/live.php
Task discussed with owner and approved.
Inspection and/or repair of the connector will require functional tests of the interface. Paul Metcalf will assist with certification. Crew Chief will need to direct the certs as usual.
Certification will take around 15 min. and should be performed when BSY and Hall C can be configured up to Beam Permit PSS State (most likely towards the end of the maintenance period).
The OPS DRVHs for the following cavities have been updated:
RF Status: Good
Tuner Status: Good
Comment: DRVH=4.000 Watch for CWWT - reduced GSET to gain some gradient
Previous OPS DRVH: 7