S-Pixie CW QRP Ham Amateur Shortwave Radio Transceiver 7.023 7.050 Mhz DIY Kits with Transparent Acrylic Shell

Power Supply: DC9 ~ 13.8V (recommended linear power supply or battery), does not distinguish between positive and negative

Antenna: 50 ohm, 7MHz, VSWR 2.0 or less

Receiving Quiescent Current: 20mA

Emission current: 120mA

Transmitting power: 1.2W

Frequency: The oscillator frequency emission; receiving local oscillator frequency

Mode: CW

Key: Manual key

Automatic transmitter: Not supported

Sidetone: None

he circuit principle:

See schematics: with the surrounding elements constituting a typical Colpitts oscillator and keeps oscillating (it has about 1mW when receiving an oscillating signal leakage), the LO signal is coupled directly to the capacitor 8050.

In transmit state (key press), 8050 as a C class amplifier, the signal is amplified by 100nF capacitive coupling to the π-type low-pass filter, and then send the antenna; in the receiving state (key release), and around 9018 elements constituting the beat oscillator (BFO), 1N4001 plus high-voltage, direct current with capacitive pressure is increased at both ends decreases, the natural frequency can be increased to about 0-3KHz, can be easily received signals of 7.023MHz beat .

8050 is biased in the non-linear region (the transistor is then two diodes back to back), and the signal received by the antenna BFO signal for mixing, mixing the audio signals obtained through coupling to the 0.1uF capacitor constituted LM386 audio power amplifiers, audio signal amplified by the LM386 5 feet 10uF capacitor blocking evacuation headphones. Key not only control the LM386 power on-off switch is also biased varactor D2, so that volume changes in different states.

• "PIXIE" is mini the 40 meter band simple micro-power amplitude telegraph transceiver, 9 ~ 13.8V DC power supply.
• Resistance to change is a horizontal packaging vertical packaging, easy to solve the short-circuit resistance has long been a problem..
• Power input does not distinguish between positive and negative, and to improve the power supply range, the user can easily use 13.8V communication power supply, and do not worry about the positive and negative reversed losses..
• Increasing the transmitter side as the buzzer sound prompts (using a jumper cap shielding sound), an increase of LED lights as transmitters prompt..
• You will receive the balun kits with the instructions.Or please contact the seller for the PDF instructions. Enjoy.Thx.