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I'm ready to install four MRF422's in an amp project I'm working on.
The bias voltage is set and switched by the T-R relay (manual no COR).
Installing the transistors is a point of no return and this is my first time doing this.
As for Transformer capacitors I'm guessing based on diagrams I've found online.

Can I further tune the Input/Output T's without a VNA before I install transistors?
I do have an MFJ antenna analyzer (old model) and I've seen vids using resistors to tune Inp/Outp networks but they used VNA's.

As is now, I put 390pF on the output side of each Input Transformer and 1000pF on input side of Output Transformers. Have ceramic trimmers on Output Trans and plenty of fixed Micas to add or subtract as needed.

If I buy any more test equipment, my wife is gonna kill me.
neil

<blockquote data-quote="Naysayer" data-source="post: 792933" data-attributes="member: 57429">I&#039;m ready to install four MRF422&#039;s in an amp project I&#039;m working on.&nbsp; The bias voltage is set and switched by the T-R relay (manual no COR).Installing the transistors is a point of no return and this is my first time doing this. As for Transformer capacitors I&#039;m guessing based on diagrams I&#039;ve found online. Can I further tune the Input/Output T&#039;s without a VNA before I install transistors?I do have an MFJ antenna analyzer (old model) and I&#039;ve seen vids using resistors to tune Inp/Outp networks but they used VNA&#039;s.As is now, I put 390pF on the output side of each Input Transformer and 1000pF on input side of Output Transformers. Have ceramic trimmers on Output Trans and plenty of fixed Micas to add or subtract as needed.If I buy any more test equipment, my wife is gonna kill me.neil</blockquote>

[QUOTE="Naysayer, post: 792933, member: 57429"] I'm ready to install four MRF422's in an amp project I'm working on. The bias voltage is set and switched by the T-R relay (manual no COR). Installing the transistors is a point of no return and this is my first time doing this. As for Transformer capacitors I'm guessing based on diagrams I've found online. Can I further tune the Input/Output T's without a VNA before I install transistors? I do have an MFJ antenna analyzer (old model) and I've seen vids using resistors to tune Inp/Outp networks but they used VNA's. As is now, I put 390pF on the output side of each Input Transformer and 1000pF on input side of Output Transformers. Have ceramic trimmers on Output Trans and plenty of fixed Micas to add or subtract as needed. If I buy any more test equipment, my wife is gonna kill me. neil [/QUOTE]

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