Re: I need a V3 or V4 uBitx board.

Jerry Gaffke

A good reminder to install a 0.5 Amp fuse or polyswitch plus a series diode (1n4007 perhaps)
from power supply into the main 12v power rail of the uBitx or Bitx40 board.
Would likely have avoided all the trouble here. 
The main board does not care about the forward voltage across the diode.
Fusing most of the rig at only 0.5 Amps means far less damage will occur before that fuse blows.

I keep have a separate fuse of 3 Amps from power supply into the PA-PWR rail.
Don't bother with a diode there, since if reverse polarity does occur the IRF510 intrinsic diodes
will conduct and blow the 3 Amp fuse.   When running from a battery, would prefer not to have
a diode drop into the IRF510 drains, as it reduces available power out.


On Sat, Jun 23, 2018 at 02:23 pm, Don, ND6T wrote:
No, looks like TX to one of the many ground connections on the kit board. Quite solid, thus the smoked trace. There is something else going on, too. Probably minor. -Don

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