Prototype KPA500 monitor

[ANDY DURBIN]

The discussion of the impact of antenna system load on PA dissipation inspired me to create a display of KPA500 RF output, PA DC input, PA dissipation, and PA efficiency.   The real time display is a lot more convenient than post processing data logger values in Excel.

https://www.dropbox.com/s/h4dtxrlm891s5b9/Prototype%20KPA500%20Monitor.pdf?dl=0

73,
Andy, k3wyc




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[ANDY DURBIN]

I received a few off list replies and  have updated the report to add the following:


Note - the displayed results are for a test with a well matched dummy load.  Efficiency and PA dissipation are dependent on frequency, output power, and the antenna system load.  Higher dissipation and lower efficiency may be seen in normal operation.


https://www.dropbox.com/s/bypkedec3v6j18r/Prototype%20KPA500%20Monitor%20rev%20a.pdf?dl=0



73,

Andy, k3wyc






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[ANDY DURBIN]

No interest shown here but I have been asked for more information off list.   Since the work is done I'll share it here.

The attached will give you some idea of how PA dissipation and PA efficiency change with output power and loading.   These plots are from a test I ran last year, long before the KPA500 Monitor page was added to my Arduino interface.  The introductory para of the incomplete report is quoted below:


"Summary

A semi-automated test was run for various frequencies and PA load conditions.  Spectrum lab was used to generate a 1,000 Hz tone with a sawtooth amplitude profile.  This tone was used to modulate the TS-590S exciter. An Arduino based data logger recorded serial data from the KPA500 and an LP-100A.  These data were processed in Excel by using a pre-defined template.  The LP-100A provides SWR, Z, and phase angle.  X and R were computed from Z and phase angle."


73,

Andy k3wyc


https://www.dropbox.com/s/r0jq4vdgdndgj53/KPA500%20PA%20diss%20and%20effic%20k3wyc.pdf?dl=0



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[ANDY DURBIN]

Rev A corrects 2 typos in the load descriptions.

https://www.dropbox.com/s/koh1oio8jywwqx9/KPA500%20PA%20diss%20and%20effic%20k3wyc%20rev%20A.pdf?dl=0

Previous file deleted.

73,
Andy k3wyc


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