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circuit explaination required

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robismyname

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I measured the voltage across R88 to be 3.1V. Input power is 5V.

I then removed P11 and P12 (Murata RF test ports) and then replaced them with 100pf caps.

I then noticed my voltage drop across R88 changed to 1.05V.

Can someone help me understand why this happened? It seems like P11 and P12 was producing some sort of biasing.

FYI

C120= 1uF
C121= 1000pF
C122= 22pF
L14= 18nH
 

I am not sure, but the connectors have switches in them so if you don't plug anything in to them you have a DC connection between U36 and U35. Can they be DC coupled? I suspect they need coupling capacitors.

Keith.
 

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