We checked POX and POY RF signal chains for sanity check since Xarm cannot be locked in IR stably as opposed to Yarm.
POX beam seems to be healthy. This issue doesn't prevent us from closing the vacuum tank.
- RF PD has SPB-10.7+ and ZFL-500NL+ attached to the RF output.
- At the demodulation electronics rack, SMA connectors are used everywhere.
- With Yarm flashing at ~1, RF output has ~24 mVpp right after RF PD, ~580mVpp after SPB-10.7+ and ZFL-500NL+, and ~150mVpp at right before the demodulation box.
- There is roughly a factor of 3 loss in the cabling from POY RF PD to the demodulation rack.
- Laser power at POY RF PD was measured to be 16 uW
- RF PD doesn't have amplifiers attached.
- At the demodulation electronics rack, N connector is used.
- With Xarm flashing at ~1, RF output has ~30 mVpp right after RF PD, and ~20mVpp at right before the demodulation box.
- Losses in the cabling from POX RF PD to the demodulation rack is small compared with that for POY.
- Laser power at POX RF PD was measured to be 16 uW
- POX and POY RF PDs are receiving almost the same mount of power
- POY has larger error signal than POX because of RF amplifier, but the cable loss is high
- There might be something in the electronics, but we can close the vacuum tanks