Intermodulation measurement Micro PA50-3

Hi everyone,

on this reflector there already have been some threads on the Micro PA50/PA50+.

There is now a version 3 available (Micro PA50-3) and I’m currently trying to check it’s RF parameters. For what I can see now input SWR is not perfect but ok (1.4…1.6) and harmonics are also fine (-50…-60dBc).

I also was trying to do IM3 measurements and found that the PAs automatic band selection is going mad when I apply a dual tone. For example I’m measuring at 14.300MHz and the PA automatically switches to 30m. Power/SWR/Frequency shown on the PA are not correct. This does not happen when just applying a single carrier. As far as I can see, the automatic band selection can not be turned off.

Has anyone seen this behaviour before, and/or does anyone know if it is possible to fix the band without having the automatic selection in place?

I know that there is a support group on facebook, but I don’t use FB at all.

Happy to share my results in case I succeed with the measurements.

vy 73

Simon, DJ4MZ/F4VVG

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