Back in 2009, Jenne replaced the PMC board mixer with a Level 13 one. Today I noticed that the LO level on the PMC screen was showing a LO level of ~5-10 dBm and fluctuating a lot. I think that it is related to the well known failure of the Mini-Circuits ERA-5SM amplifier which is on the D000419-A schematic (PMC Frequency Reference Card). The Hanford one was dying for 12 years and we found it in late 2008. If we don't have any in the blue bin, we should ask Steve to order 10 of them.
The attached trend shows 2000 days of hour trend of the PMC LODET channel. The big break in 2009 is when Jenne changed the mixer and then attenuated the input by 3 dB. The slow decay since then is the dying amplifier I guess.
Since the LOCALC channel was not in the trend, I added it to the C0EDCU file tonight and restarted the FB DAQD process. Its now in the dataviewer list.
I went out and took out the 3 dB attenuator between the LO card and the PMC Mixer. The LO monitor now reads 14.9 dBm (??!!). The SRA-3MH mixer data sheet claims that the mixer works fine with an LO between 10 and 16 dBm, so I'll leave it as is. After we get the ERA-5, lets fix the LODET monitor by upping its gain and recalibrating the channel.