- #36
Baluncore
Science Advisor
2023 Award
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Both the diode and the transistor will be forward biassed and will operate with the +3V supply. The LED, (as shown in the video), illuminates when there is sufficient audio input. The LED is forward biassed, so it gives a couple of volts compliance for the oscillation of both phases. Build it and take a look, or simulate it and you will see.StandardsGuy said:The diode serves no useful purpose and looks to be in backwards, but no polarity of voltage is shown.
The transistor bias current is limited by the audio source provided in the kit. The LED and the +3V supply in the kit limit the collector current. It is the half wave bias that generates the AM signal.StandardsGuy said:There is little current limiting in the circuit, so the transistor may fail from excess current, except that the transistor has no bias.
Yes, but it is more than sufficient to demonstrate the AM modulation on an AM receiver where only 10 uV of antenna input is needed.StandardsGuy said:The inductor is a very poor antenna.
If it worked any better it would need more than a "very low" EIRP class license.StandardsGuy said:How does it work? Poorly if at all.