NAOJ GW Elog Logbook 3.2
[Logan, Marc]
Following the reinstallation of the mixers box we could not lock the GRMC.
We found out it was because the DDS2 was not generating any sidebands but was just outputing some low amplitude broadband noise.
We could see that this issue was somehow related to the 500MHz clock as the software could not recognize it from time to time.
Today we checked the DDS2.
All voltages supply are correct.
All output (filtered or not) are just noise increase.
Then we checked the 500 MHz clock output and got
Channel 1 : -8.6dBm
Channel 2 : -16.7dBm
Channel 3 : -19dBm
Channel 4 : -21 dBm
We checked the output of Wenzel output and got -8dBm.
It seems there are some issues with the splitter (ZFRSC-4-842-S+) that creates the low clock power.
We swapped the clock of DDS2 to channel 1 and got the expected output powers.
We'll check if the remaining amplifier can be used for this clock output or if we have to purchase a new splitter.
[Logan, Marc]
We added one of the 2 remaining RF amplifier to the 500MHz clock output.
We soldered it to the NIM rack +12V and ground used for the LNVR. Note that we could have tried to use the +12V from the LNVR but were a bit worried to further damaged the clock..
The output of the clock is now +7.9dBm.
The output of the following splitter are
1 : -1.73dBm ; 2 : -6.19 dBm ; 3 : -5.09 dBm ; 4 : -5.33 dBm
Finally, we connected DDS2 to each output of the splitter and checked the signal output from DAC0.
We got about -9 dBm from all.
Next steps are fixing the clock crystal (was not fixed anymore) and the RF amplifier ; recover the electronic connections and recover squeezing.