John Parfrey:
Modified Sine Wave (square wave) from Inverter
John Parfrey:
Crystal Radio
John Parfrey:
iPhone logic board cooking nicely
John Parfrey:
811A Valves
John Parfrey:
811A Valves
John Parfrey:
3.5kV Panel Meter
John Parfrey:
Homemade Linear Amplifier
John Parfrey:
High current MOT transformer
John Parfrey:
1:1 "Guanella" Current Balun
John Parfrey:
Homemade 1.25v - 30v variable bench power supply - inside!
John Parfrey:
Homemade 1.25v - 30v variable bench power supply @ 13.8v
John Parfrey:
Homemade 1.25v - 30v variable bench power supply
John Parfrey:
Homemade Class A audio amplifier - Front
John Parfrey:
Homemade Class A audio amplifier - Rear
John Parfrey:
Homemade Class A audio amplifier
John Parfrey:
Inside the Class A audio amplifier
John Parfrey:
2N3055
John Parfrey:
Inside the homemade DOZ Class A amplifier
John Parfrey:
Multimeters
John Parfrey:
Homemade HF amplifier unfinished
John Parfrey:
CW Capacitive Touch Key Board
John Parfrey:
Kinkless Tetrode 88 (KT88) vacuum tube
John Parfrey:
Nevada TM-1000 Antenna Tuner
John Parfrey:
RF Current Meter
John Parfrey:
4m 70MHz Spectrum Transverter PA board.
John Parfrey:
The start of my KT88 Single Ended audio amplifier.