Yuhang, Eleonora

We installed 12 dB attenuator on the LO of the QPD2 demodulation board, as we did for QPD1 demodulation board 1 (see entry #2112)

We performed the same test and confirmed all the channels are working fine.

The LO was -6dBm, we notice that if we put additional attuantion the demodulated signal is slightly increased. For a LO of -21 dBm the demodulated signal reaches the maximum amplitude and it is a factor 1.2 higher that in  -6dBm case.

Anyway we will split -6dBm LO between the 2 demodulation boxes. The actual LO for each board will be -12dBm which is fine.