UpTech Store Efficiency Kit Lo
Posted: 27 Nov 2022, 06:35
Hello all,
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:
After removing one turn form L12, L31, L42 and realignment with nanovna. I was able to get this. (I intend to add another turn to L51 to lower the power but I haven't done that yet.)
After a number of times going back with nanovna and adjusting coils I wasn't able to get above 74% efficiency. I read through the forums and I noticed some people mentioned lowering windings on L15 from 22 to 19 improved efficiency. There was also a link to a video by DL2MAN talking about the wire diameter originally being 0.4mm and the kit now had 0.54. Therefore 19 windings should be fine. So I got out my calipers and measured the wire which turned out to be 0.5mm. I lowered the windings to 19 and remeasured. I noticed a slight increase in power but no change in efficiency.
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.
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:
Code: Select all
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, 74.34Code: Select all
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, 74.34Right 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.
