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Entry  Thu Apr 4 18:40:18 2019, anchal, DailyProgress, Mode matching, Re-aligned South Path 
    Reply  Fri Apr 5 19:28:56 2019, anchal, DailyProgress, Mode matching, Re-aligned South Path 
Message ID: 2316     Entry time: Fri Apr 5 19:28:56 2019     In reply to: 2315
Author: anchal 
Type: DailyProgress 
Category: Mode matching 
Subject: Re-aligned South Path 

Today I aligned the south path completely with about 60% matching with the cavity. I guess I got lucky or I really know how to do this correctly now (see PSL:2253).

I have just one last weird thing remaining in South Path. The South Cavity Reflection RFPD doesn't behave well with its RF cage lid on. More specifically, the +5V voltage regulator LM309H stops working for some reason and +5Vrail becomes -0.6 V. But with lid off, everything works. I was even able to lock FSS nicely. So something is going on which I am trying to understand for a long time now. I have replaced MAX4107ES, LM309H and capacitor at the input of LM309H, but nothing works. The RF cage has a layer of electrical insulation tape from the inside, so there is no chance of it shorting any tall component (only tall component is an Inductor, see PSL:2241). I'll look a little bit more into this on Monday but otherwise, I'll just go ahead and install RFPD without this RF cage lid. Anyways the box itself should provide pretty good insulation from RF interference. If anyone has any clues about this -0.6V issue, please help me.

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