transformers of various Q's. So i have decided to make a transistor
radio from scratch using parts from my scrap parts collection.
Today i built a 2 stage IF amplifier, where, each stage provided
about 30 dB of gain. Circuit Q was very high, set by the IF
transformers which coupled each stage together.
I built a full-wave envelope detector using one of the IF
transformers and two germanium diodes.
I injected a tone into the base of the first stage and sucessfuly
used it as a mixer.
I successfully tuned in AM broadcast bands by injecting an LO into
this mixer, listening to local sports and talk stations.
Next steps:
1. need to build a VFO that can swing a couple of volts on the output.
2. modify the IF amps so that they are adjustable gain
3. build a front-end that is band-limited with a bandpass filter or
adjustable resonator transformer of some kind.
4. look into using this at short-wave frequencies, might have to
build an RF amp and pre-selector.
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