[Marc, Shalika]

We removed the 3 broken amplifiers from DDS3 (ie the ones connected to DAC1,2,3).

We confirmed that the ground and +12V were correctly provided.

We soldered the DAC1 amplifier, brought it to TAMA to test the output and measured the expected 9dBm.

We then soldered the 2 remaining amplifiers.

We then measured :

DAC0 -> 6.5dBm

DAC1 -> 9dBm

DAC2 -> 9.6 dBm

DAC3 -> -23 dBm

Because we did not remove DAC0 amplifier before installing the new amplifiers, we suspected that some bad connections could explain the too low output of DAC3.

We tighten better the connections of all amplifiers and this time we got

DAC0 -> -20 dBm while all other outputs were same...

We tried to untighten a little the connection and this time DAC0 -> -36 dBm (other unchanged)..

We need to investigate the reason for this drop (maybe same as what happened before that `broke` the amplifiers?)