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Showing posts from February 11, 2012

The BLF177 some better result

Few days later I changed the coils in the lowpass filter. Almost doubled the inductance from the RFsimm calculated values. Also thicker wire used 1.2mm .  And the Spraque C's replaced by an Arco 80pF compression type trimmer. Now the heat developed is much lower and the efficiency increased to about 50%. Great tool RFsimm99  but still I need to do the old solder work to change real components and test again.  Now the only wish is  having a bit more gain it needs >10W drive for full output.  I can not let out the 1Ohm parasite stopper at the gate. If so i see  oscillations. I tried a wire trough 1 ferrite pearl   with 3 ferrite rings no drive power came through!  1 ring i had power but the ring got hot! Messured 1 wire gives about  70nH (at 500kHz)  Those tiny rings do a lot more then thought! The BLF177 takes a lot RF gate current at low impedance.   A few days  I let it rest it was useless to continue the trial and error method. I went ice-scathing. Then I did chec


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