We are hacking the PMC card, to try to lock the PMC without using a computer.

Aidan helped me try to lock the PMC with the current equipment (LIGO PMC card, the schematic can be found here). Since, the computer for controlling the card is not here and we cannot put it back together within one week I have left, we are trying to use the card and send in signals to control the card manually. For today test, we used a spare PMC left on the crate (I think Frank used it to drive the PZT for shaking the table, long time ago. It might be modifed from what we saw on the schematic.)

We tested the control signal for the high voltage output using the following procedures.

• Power up the card with +/- 24 V with a power supply
• Use Acromag to send Vin ( I think it can send in +/- 10 V, but we used only [-6 , 2] V) .
• Use HV from the power supply on the rag with 0-200 V. 
• Measure Vout at J6 (where it will be connected to the PMC's PZT)

The HV drive is working and linear with the input control [HV = -24.1*Vin + 40] (Vin = [-6,2] V, HV = [4,185] V). At first, we injected the signal at INOFFSET2 (through R4), but we couldn't see the signal out. I'm not sure why, but we are working on it.

To do:

• Setup RFPD on the table for the PMC
• Add the EOM on the path (may be temporary, as the mount is not ready)
• Connect the LO to EOM and the PMC card
• Check Error signal
• Lock the cavity
• Note: the mysterious mode I reported in previous log may be mode hopping (as suggested by Johanness during Pizza meeting) I'll check that by operate the laser at different slow offset and see if there's any change or not