[hpsdr] Stuff,

[FRANCIS CARCIA]

hi Joe,
Take your time I have plenty to keep me busy. I'm working on my second prototype modified MRI amplifier so not operating much. This one will be on a bigger heat sink with a big slab of 3/8 copper under the FETs
I have a wireless network and want to make sure nothing is coming in from spam land while I run Hermes.


Kjell, I have not built my Munin but I wonder if the bias series diodes need a bypass cap on the cathode side. Maybe RF is getting rectified to change the operating point. 
I had all kinds of problems with my modified MRI amp when a very low level 80MHz oscillation was getting into the bias circuit and causing a positive offset. When drive was applied the offset went away causing a bias shift toward class C. This trashed the IMD. I put 470 ohms in series with ,1uf gate to drain on each of the 8 FETs and problem went away.  Take a close look at the output with a scope. 
My IMD is great with Warren's magic running. 4 stages of amplification and better then -50dBc IP3.
Frank WA1GFZ 
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