The AM Forum

I have made an Excel spreadsheet that calculates the values for Class E power amplifiers.  I used the January 2001 QEX article by Nathan Sokal WA1HQC as the reference.

The L network to match the ouput impedance of 50 Ohms is included on the output of the basic tank circuit.

For INPUT DATA, you enter Q, frequency, Vcc, drain breakdown voltage, transistor saturation voltage (Vo), desired r.f. output power, expected PA efficiency, and L1 feed choke reactance factor.

For RESULTS, you get DC Input power, DC current, peak Vdrain, drain BV safety factor, R, DC feed impedance, dc feed choke L1 inductance value in uH., shunt cap. C1 value in pf., series tank cap. C2 value in pf., series tank inductor L2 value ( includes L matching inductance) in uH., and "loading" cap. C3 value in pf.  

C1 and C2 values are calculated to compensate for the value of L1 feed choke, per the final terms in Nathan Sokal's C1 and C2 formulas.  So those who want to use a low value of feed choke will get proper C1 and C2 values.

All of this should make the spreadsheet fairly universal in use.

The spreadsheet is produced 3 times in the 39 kbyte book, with tabs for 75 meters, 160 meters and 40 meters. This way, you can keep separate data for the 3 bands and compare easily.  The sheet is already formatted for a portrait-oriented print-out also.

Anyone wishing to check it out, send me a PM with your e-mail address included, and I will e-mail you the file as an attachment.  I'd be interested in feedback.