Amplifier for 6 meters

[VK4RW]

Hi Ron

The MRF492 is rated for a maximum output of 70W.  It loses linearity if used above this power level.

I have modified DSE K6349 100W PAs that use two MRF492s from 100W to 130W output.  This involved replacing the PA coil with a much heavier gauge wire and likewise the filter coil and capacitors.  It also greatly improving the bias circuit which is not just a simple diode based one.  

A single MRF492 will not get you a clean 100W especially if a simple diode based bias circuit is used as per the DL5DBM article.

73s

Igor

Hi Igor

The transistor being used in the amplifier is now a 2SC2879.  After receiving some excellent advice I discarded the MRF492.

Between natural disasters, I am wiring up the switching relays, so almost ready to go.

73

Ron

Hi Ron

The 2SC2879 is a better transistor but it is listed as a 2-30 MHz device so may not work too well at 50 MHz.

73s

Igor

Hi Igor

I did note that on the datasheet, but it was in the junk box, so nothing to lose.  All in the name of experimentation.

Thank you for your interest in the project.


73
Ron