Evan,
That all looks good, thanks for doing such a thorough analysis!
IMD could vary wildly depending on mike gain, and RV1 setting.
Also, various builds may have significantly different gains due to differences in filters and transistors.
Would be useful to know a bit more about how you conducted the IMD test:
? What tones were injected into the mike jack, and at what level.
? Exactly which unwanted product was observed when measuring IMD
? Signal level observed into Q90.
? Power out to the dummy load.
Just figures for 40m would be most helpful.
I doubt this signal is any wider than an AM phone station,
and should thus be quite acceptable at these power levels.
Of course, creating nearby hash in low power digital mode watering holes could be of concern.
IMD is of even more concern if the uBitx is used with a high powered linear.
Jerry, KE7ER
On Sun, Apr 11, 2021 at 07:50 AM, Evan Hand wrote:
I did do the testing of my modified v4 against my unmodified v5.? I have posted the power levels of the v4 on this thread.? The IMD measurements that I got are as follows:
