I recently purchased the kit from UpTech store through aliexpress. I assembled the boards as per "(tr)uSDX #2 - complete assembly Instructions" video and the schematic. I have flashed both the bootloader and the firmware (stable) onto the board following the steps on the website. I've setup the features in the menu as per DL2MAN's video "(tr)uSDX #4 - How to use it" and I've followed the "(tr)uSDX - Tuning the RF Section for Output Power and Efficiency" utilising a nanovna and a 50ohm dummy load.
My first readings after aligning the second harmonic (running 12V/1A PSU) for each band was:
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Name, Band (M), Freq (Mhz), Power (w), Efficiency (%)
L1, 20, 14.06, 3.19, 69.37
L2,30, 10.106,4.73, 73.75
L3, 40, 7.03, 3.38, 73.6
L4, 60, 5.351.5, 3.72, 72.75
L5, 80, 3.56, 6.35, 74.34
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Name, Band (M), Freq (Mhz), Power (w), Efficiency (%)
L1, 20, 14.06, 4.3, 70
L2,30, 10.106,4.73, 73.75
L3, 40, 7.03, 4.7, 74
L4, 60, 5.351.5, 4.99, 74
L5, 80, 3.56, 6.35, 74.34
Right now i'm unable to get above 74% efficiency. Does anyone have any recommendations on what to try?
Update: I haven't tried the "Suggested Mod of T2 for Efficiency Improvements" I just followed the windings as detailed in the schematic/iBOM. I'll give that a shot but if anyone has anything else I should look at , please let me know.