When should I expect the cooling fan in my 6300 to increase its' speed.

RoyS

On my 6300, I cheated the setup and ran 30 watts while running JT-65. Keeping in mind the duty cycle of a constant signal, I placed a temperature probe at the exhaust and measured the air temp.
I saw a max temp of 45 deg C. The fan speed never changed. Since there is no adjustment like on my 3000, I wonder at what temp should the fan speed increase?

Roy - W5TKZ  

Dave - WB5NHL

According to an earlier Flex posting in this community the fans switch to hi speed at 70 degrees C and return to low at 55 degrees C. The temp is measured on the flange of the PA transistors. The absolute max temperature for the PA transistor junction is 175 degrees C.

DrTeeth

I run DDutil and it gives a PA temp reading. Maybe more reliable than measuring air temp?

KY6LA_Howard

I believe you are correct about DDUTIL

Steve-N5AC

The PA temp reading reported by SmartSDR (which DDUtil displays) is the temp we use to adjust the fan speed.  For testing in the lab, we use a thermocouple inserted into the heat sink and found that the temperatures are fairly close.  The reported temp and heat sink temp lag the junction temp, of course.