EMRFD Message Archive 14464

Message Date From Subject
14464 2017-12-22 17:08:02 kc0vsj High Speed Class E Drivers for Paralleled BS170

Using the 3.3v output from the Si5351 to drive three paralleled BS170's in the QRP-Labs QCX is accomplished with 74HCT00N IC's.  The HCT series parts are fast, and have a turn on level below 3.3 volts, and running  on 5volts they make a nice level converter/driver as well as making possible some logic for keying etc.

Is there a minimalist solution for a two transistor (NPN/PNP pair) that will let me do this at speeds over 30Mhz.  Complementary 2n2222/2n2907 open collector design  rise and fall times seem to be  less than the HCT switching times and I am wondering if there is a faster part.

My interest in doing this is to do Manhattan builds of the QRP-Labs Class E design and compare it to the Cripe design.  I have a 30m QCX with 1.5watt output at 12volts which isjust  a bit under what Spice simulation seems to show.  The Cripe design seems to have more output and I am just trying to figure it out.