12meter xband total power ripples & jumps


01,3,5mar16 - measuring the drift. telescope sitting
10mar16       - changing the attenuator
13,14mar16  - monitoring the drift after attenuator changed.


    Jumps,ripples  in the xband power was seen with the udc & mock spectrometers (only polB was monitored). The ripples correlated with the dehumidifier running in the pedestal. Some debugging showed an instability in the rf filter, attenuator interface in the rf chassis in the pedestal. Changing the attenuator caused the ripples and jumps to decrease in amplitude.

01,03,05 mar 16: monitoring the xb total power. (top)

    On 01,03,05 mar16 simultaneous data was taken with the sb and xb receivers on the 12 meter telescope. This was before the attenuator after the the xb rf filter was replaced (on 10mar16).
The setup was:

Plots of total power vs time.


processing: x101/   160301/p12mripple.pro, 160303/ripple_dehumidifier.pro 160305/ripple_dehumidifier.pro

160310: changing the attenuator in the rf box. (top)

    On 160310 we opened the polb rf chassis in the pedestal. We than took mock data (see above setup) while probing in the box. What we found was that:
processing: x101/160310/p12mxbdrift.pro (lists when we touched things).

160313-14: monitoring xband power for 16 hrs. (top)

    Monitor data was taken taken with xband polB starting at 22:42 on 13mar16 (see datataking setup above). It continued until
16:00 on 14mar16.

    The plots show the polb power vs time (.ps) (.pdf)


processing: x101/160313/p12msitting.pro

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