How does one determine / calculate the input impedance in a cathode driven GG circuit? A pointer to a book / article would be great. THX, Bill * * * * * * * * * * * * * * * * * Bill Coleman N2BC http://home.stny.rr.com -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com