Colpitts Gennie -not Armstrong this time
Posted: Thu Aug 15, 2024 6:01 am
The Colpitts approach uses no tickler coil nor throttle capacitor for regeneration, as opposed to the Armstrong circuit. In our case, it resorts to transistor Q1's base-emitter input capacitance and NPO-type ceramic capacitor C2 to effect the correct impedance transformation and phase shift necessary for regeneration to take place. Q1 is the amplifier-detector and along with its associated circuitry forms the common-collector Colpitts regenerative amplifier, with R9 as the reaction control.
The design comes from Ramon Vargas Patron - Lima Peru,and further details are available at: https://www.cxi1.co.uk/Circuits/rf/swr.htm
The high impedance audio output might be improved with a simple amp (even IC) and maybe drive a speaker?
The design comes from Ramon Vargas Patron - Lima Peru,and further details are available at: https://www.cxi1.co.uk/Circuits/rf/swr.htm
The high impedance audio output might be improved with a simple amp (even IC) and maybe drive a speaker?