Mod proposal to PHSNA



Several times that I started to use my PHSNA I got a totally flat sweep graph. It was caused by forgetting to connect the 12 V supply, and since the Arduino is powered by the USB connection, the program does not detect that the Power Detector and the DDS modules are unpowered.
An easy modification is to connect any of the free analog inputs of the Arduino to the 12 V rail using a resistive divider, and modifying the PHSNA windows program to check the 12 v presence as part of the initialization routine.
But later I thought that using a DC/DC converter powered by the +5 V rail to obtain 12 V is a more convenient way, so I'm planning to install one of these cheap Chinese converters ( less than $1) and see if the 5 V regulator in the Arduino can cope with the needed current. Maybe it will need some extra filtering in the 12 V bus but it seems quite feasible.
I'll inform about the results when I finish my tests.

Ignacio, EB4APL

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