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Entry  Sat Nov 21 00:45:30 2015, Koji, Update, IOO, IMC fix PDRFsignal_cable.JPGQsignal_cable1.JPGQsignal_cable2.JPGQsignal_cable3.JPG
    Reply  Sat Nov 21 00:46:33 2015, Koji, Update, IOO, IMC OLTF IMC_OLTF.pdfPMC_noise_comparison.pdf
       Reply  Sun Nov 22 12:12:17 2015, Koji, Update, IOO, IMC OLTF 
    Reply  Sun Nov 22 07:09:01 2015, rana, Update, IOO, IMC fix 
       Reply  Sun Nov 22 12:07:09 2015, Koji, Update, IOO, IMC fix 
          Reply  Mon Nov 23 22:12:10 2015, Koji, Update, IOO, LO level check for the IMC demod board IMG_2137.JPGIMG_2138.JPG
             Reply  Wed Nov 25 04:24:21 2015, rana, Update, IOO, LO level check for the IMC demod board 
                Reply  Wed Nov 25 10:07:10 2015, Koji, Update, IOO, LO level check for the IMC demod board 
                   Reply  Wed Nov 25 16:46:10 2015, Koji, Update, IOO, LO level check for the IMC demod board D990511-40m_151123.pdf
                      Reply  Wed Nov 25 20:07:35 2015, rana, Update, IOO, LO level check for the IMC demod board 
                   Reply  Mon Nov 30 14:12:14 2015, ericq, Update, LSC, LO level check for the LSC RF distribution box 
                      Reply  Mon Nov 30 15:17:57 2015, Koji, Update, LSC, LO level check for the LSC RF distribution box 
Message ID: 11825     Entry time: Mon Nov 30 14:12:14 2015     In reply to: 11808     Reply to this: 11826
Author: ericq 
Type: Update 
Category: LSC 
Subject: LO level check for the LSC RF distribution box 

I checked the RF levels at the LSC LO distribution box, with the agilent scope and a handful of couplers. This was all done with the Marconi at +13dBm. 

I only checked the channels that are currently in use, since the analyzer only measures 3 channels at a time, and rewiring involves walking back and forth to the IOO rack to make sure unpowered amps aren't driven, and I was getting hungry. 

For the most part, the LO levels coming into the LSC demod boards are all around +1.5dBm (i.e. I measured around -18.0dBm out of the ZFDC-20-5 coupler, which has a nominal 19.5dB coupling factor)

The inputs piped over from the IOO rack, labeled as "+6dBm" were found to be 4.7dBm and 2.9dBm for 11Mhz and 55MHz, respectively. 

The 2F signals were generally about 40dB lower, with two exceptions:

  • REFL165's ~332MHz signal was around -18dBc
  • POP22 had many more visible harmonics than any other LO signal
    • 11MHz: -32 dBc
    • 33MHz: -32 dBc
    • 44Mhz: -15dBc 

Here are the raw numbers I measured out of the couplers, all in dBm:

  • 11MHz in: -14.8
  • 55MHz in: -16.6
  • POX11:    -18.7
  • POY11:    -18.0
  • REFL11:   -18.0
  • REFL33:   -18.3
  • POP110:   -17.9
  • AS110:    -18.1
  • POP22:    -19.9
  • REFL165:  -18.5
  • AS55:     -18.6
  • POP55:    -18.8 (this port is used as the REFL55 LO)
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