Related wiki page: List of DC QPDs
Here is an executive summary:
- The QPD is physically taken out.
- The reverse bias voltage is decreased to 3V from 15 V to adapt it for FGA21s.
- The transimpedance gains were increased.
- A set of cables were directly soldered onto the circuit and their ends were connected to a DB9 male connector.
The technical details can be found in the JGW document server at S1707229.