The 75 Meter QRP SSB Transceiver Theory of Operation 6-30-03 In general, the transceiver switches the 4-element 1500 ohm xtal BPF ends between the inputs and outputs of the two SA602s to reverse the signal flow for R/T operation. Since no IF amplifier is used in the design, 20 dB of additional receiver gain is […]
Posts tagged 2N2222，
Audio circuit using 12AX7, 2x6BQ5, EL84 Audio circuit using 12AX7, 2x6BQ5, EL84
Description of the New Circuit A brief description of the assembly, product, or sub-system for which this printed circuit board or PCB is currently in development for. Conductor Layout Guidelines Multi-layer Printed Wiring Boards A multi-layer board should be used with internal conductor layers. Each layer should be separated by a power or ground plane. […]
Circuit diagram keytop and display A keyboard “key figure” who work with electrical contact between the surface of the keyboard and the underlying circuit when pressed keytop area, used by some home computers the early 1980s, and has been widely used in consumer electronic devices.
Power Supply Control circuit Power Supply Control using LM7812, LM7912