<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>hi Joe,</div><div>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</div><div>I have a wireless network and want to make sure nothing is coming in from spam land while I run Hermes.<br></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: 'times new roman', 'new york', times, serif; background-color: transparent; font-style: normal;"><br></div><div>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. </div><div>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. </div><div>My IMD is great with Warren's magic running. 4 stages of amplification and better then -50dBc IP3.</div><div>Frank WA1GFZ </div></div></body></html>