[Marc, Shalika]

Yesterday we checked again DDS3 outputs and got similar results as last time (3178).

We opened the box to check the +12V/GND provided to each amplifiers. We found that DAC0 and DAC3 were not receiving the expected voltage.

DAC3 +12V cable got easily disconnected and we found that DAC0 +12V pin was extremely tilted..

We removed DAC0 amplifier and soldered a new one. We also resoldered DAC3.

Our guess is that all the +12V/GND cables have a strong strain and twist due to the limited space in the board. So we replace the connection to the board output from a SMA female to female connector to a about 5cm length SMA cable.

All the ouputs of the board are now as expected :

DAC0 8.8dBm

DAC1 9 dBm

DAC2 8.6 dBm

DAC3 8.6 dBm

Maybe the strong twist of DAC0 amplifier +12V pin was the reason for all our issue?

Also the board inside is now quite messy. If we want to tidy it we should prepare some custom length SMA cables.