[kTanaka, Hirose]

We have finished crawling the cables between the racks at klog29281, klog29466 and klog29602. We connected the cables for WFSf3(PDF file ). Power is all switched on.

Detail

• Measured the output of the function generator before connection. Both outputs at the function generator were about 13 dBm, so we set a 3 dBm attenuators at the input part of each of the RFamp to output 13 dBm as designed for the RFamp.

• 	Outputs of Fanction genereter	Inputs of RFamp After added 3dBm attenuator
  11.25MHz	13.21dBm	10.01dBm
  89.99MHz	12.48dBm	9.68dBm

• And we connected the outputs of each RFamp. Measurements and connections are as follows. 

• RFamp	Output port 1	Output port 2	Output port 3
  11MHz	12.60dBm (WFS1, LOW)	12.59dBm (WFS4, LOW)
  90MHz	11.81dBm(WFS3, HIGH)	11.88dBm(WFS4,HIGH)	11.79dBm (LSC)

  Measurement result: /Dropbox/KAGRA/Measurements/IFO/ASC/REFL/WFSf3/20240606
  Originally, the excitation signal was sent directly from the harmonic generator to the I&Q demodulator of the 90 MHz RFPD in the LSC rack, but an RFamp was inserted. 
  The 90 MHz excitation signal to the I&Q demodulater of the 90 MHz RFPD in the LSC rack has been reduced by 0.69 dBm from 12.48 to 11.79. We checked the error signal before and after the work and found that it had dropped slightly.(FIG.1, 2 ) 
  No light is coming to the RFPD at this time, so we were looking at dark noise. May need to be investigated when light arrives.
  We also checked the frequency spectrum and found no change. But there was a 50 MHz line. I'm not sure. But there may be a signal being passed around from the RFamp.(FIG.3 ) 

Note

• The same process was followed as in klog27900 for measurements and connection.