Farhan,
It is good to know that the SMD devices installed on the sBitx are COG 250 volts.? That is far and above the needed rating for the V3 power levels.? Do you know the size?? It would make it easier for Jack to order the correct part to replace.
The rating means that overvoltage was not likely the factor causing the capacitor to fail.? The question is if the sBitx ever worked on 17 meters, or was it a bad part when built?? Rereading Jacks's post, it looks like it did work at one point.? Even with the potential of 40+ watts with the V2 hardware, the voltage would not have come close to the 250vdc rating of the filter capacitors.? It would be only with a severely mismatched load.? At 50 ohms, 40 watts is a 63 volt peak, and 110 volts is at 3:1 SWR.? Beyond 3:1, I am unsure if you can assume the 40-watt power to calculate the voltage (P=Vpp^2/2R).? This would best be done with measurements.
Thank you again, Farhan,? for the information.
73
Evan
AC9TU
