Hello All I have a Well trusted HP 8648C signal generator I used for many years. It has the high output option (20dBm output). It has now low output around 2-3dBm output maximum and it is not stable in amplitude. I have ruled out the Attenuator and Reverse power protection. I measure the power direct on the output module.

I heard about Failure of the output MMIC. Can anyone comment on that.

I have seen that MMIC type for sale on Alibaba page. Has anyone ever tried buying that component from them. Is it safe to assume the part is genuine ?

73 Peter OZ1LPR