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Entry  Wed Apr 3 17:40:18 2013, Jamie, Configuration, Electronics, putting together a 110 MHz LSC demod board 
    Reply  Wed Apr 3 18:41:22 2013, Jamie, Configuration, Electronics, putting together a 110 MHz LSC demod board 
    Reply  Wed Apr 3 22:26:51 2013, rana, Configuration, Electronics, putting together a 110 MHz LSC demod board 
       Reply  Thu Apr 4 14:37:15 2013, Jamie, Configuration, Electronics, putting together a 110 MHz LSC demod board 
          Reply  Mon Aug 26 18:55:18 2013, Jenne, Configuration, Electronics, putting together a 110 MHz LSC demod board for AS AS110_demod_board_modifications.pdf
             Reply  Mon Aug 26 20:13:17 2013, rana, Configuration, Electronics, putting together a 110 MHz LSC demod board for AS 
                Reply  Tue Aug 27 15:31:48 2013, Jenne, Configuration, Electronics, putting together a 110 MHz LSC demod board for AS 
                   Reply  Tue Sep 3 21:10:36 2013, Jenne, Configuration, Electronics, putting together a 110 MHz LSC demod board for AS 
             Reply  Tue Aug 27 17:32:52 2013, Jenne, Configuration, Electronics, putting together a 110 MHz LSC demod board for AS 
                Reply  Tue Aug 27 18:21:35 2013, Jenne, Configuration, Electronics, 110 MHz LO options 
                   Reply  Tue Aug 27 18:58:52 2013, Koji, Configuration, Electronics, 110 MHz LO options 
                   Reply  Mon Sep 2 16:46:32 2013, Jenne, Update, Electronics, RF distribution box is on the bench 
                      Reply  Mon Sep 2 18:06:21 2013, Jenne, Update, Electronics, RF distribution box: 110 MHz LO options RF_distribution_box_proposed_modifications.pdf0902131751.jpg0902131751a.jpg
                         Reply  Tue Sep 3 21:08:13 2013, Jenne, Update, Electronics, RF distribution box: 110 MHz LO options 
                            Reply  Wed Sep 4 16:06:40 2013, Jenne, Update, Electronics, RF distribution box: Reinstalled 
                               Reply  Wed Sep 4 21:44:54 2013, Not Jenne, Update, Electronics, RF distribution box: Reinstalled 
Message ID: 9072     Entry time: Tue Aug 27 18:21:35 2013     In reply to: 9071     Reply to this: 9073   9095
Author: Jenne 
Type: Configuration 
Category: Electronics 
Subject: 110 MHz LO options 

As I see it, we have a few options for getting the 110 MHz LO to both the POP110 and AS110 demod boards.  

The current situation is described by Kiwamu in elog 5746.  The 55 MHz signal comes into the box, and is split 4 ways, with each path having 19.7 dBm.  One of these 4 is for 110.  It has a 2dB attenuator (giving us ~17.7 dBm), and then it goes to an MK-2 frequency multiplier.  I'm a little lost on why we're giving the MK-2 17 dBm, since it says that it can handle an input power between 1 - 15 dBm.  It has ~16 dB conversion loss, so the 110 output of the distribution board has (according to the drawing) 1.9 dBm.  The demod boards have a 10 dB attenuator as the first element on the LO path, so we're giving the ERA-5 -8 dBm. 

We can either amplify the 110 leaving the distribution box, split it, and then attenuate it to the appropriate level for the demod boards, or we can change the attenuators on the POP110 and AS110 demod boards. 

Since we seem to be over driving the 2x frequency multiplier, I think I should change the 2dB attenuator to a 5dB attenuator, so we're giving the 2x multiplier ~15 dBm.  The conversion loss of ~16 dB means we'll have -1 dBm of 110 MHz.  I want to amplify that by ~10 dB, to give 9 dBm.  Attenuate by 5 dB to get to 4 dBm, then split into 2, giving me 2 110 MHz spigots, each of ~1 dBm.  Since the demod boards expect between 0-2 dBm for the LO's, this should be just fine.

Thoughts, before I start scrounging parts, and pulling the RF distribution box?

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