Two BJT Transceiver for 40 Meter Band
ABACUS-3 by DL6ZB
Here is a very simple constructed 2 BJT transceiver. I made it for the 40m band.
The variable resistor is trimmed for best receiver performance. Signals are loud and clear with high-Z headphones.
The variable capacitor is trimmed for best output power which should be about 80 mW.
The power can be increased by using changing the 56 ohms resistor to a
lower value. Do not go below 22 ohms. A heat sink is mandatory.
This transceiver perfoms surprisingly well regarding it's low power and poor receiver.