BLF188XR one tough device

[VE3ELQ]

Last night I was on 160M using my dual BLF188 amp when I noticed the power meter hitting the stops and the fans at full speed which they rarely do.  A quick check showed Vdd was 69 Volts instead of the 50V regulated that it is supposed to be. One of the IRFP260 FETs in the regulator had failed dead short drain to source so there was no regulation yet the amp was still alive at 69 volts pumping out lots of extra watts. It was an easy fix.  Thats not an experiment I would have deliberately conducted due to the cost but it did provide a valuable data point.  These BLF188s are pretty tough devices.

73s  Nigel

[KL7OF]

Do you have a picture of the amp??? Glad it didn't fry on the overvoltage...