uSDX

Published on 2022-04-18

⚓ Symptoms

TX on 4 bands cooks the final PA (IRLML2060), the 4 others bands are OK.

Power usage, default settings, on CW, keying, power supply was limited to 700mA:

bandpower usage
80483mA
60516mA
40601mA
30517mA
20700mA
17700mA
15700mA
10700mA

Unlimiting the PSU, or setting a limit of ~800mA will ends up with the PA cooked.

The 40m band was worked on WSPR and JS8 for a few hours on unregulated 3S 18650 without issues.

⚓ Tests

Some ideas to tests: https://twitter.com/DaSharkbiscuit/status/1481926263732330497

⚓ Around 14 Jan

I did another test in Tx in CW (table upper), and the PA doesn’t seems to cook itself immediately, from what I remember, when keying, the power usage stayed around 400/500mA for one to two seconds then switched to +700mA and the PA cooked if offered more.