Qrp-cw-transceiver


Posted on May 22, 2012

This is a 3-W, single-circuit board, VFO-controlled CW transceiver for 40 or 30 meters, featuring a direct-conversion receiver with audio filtering, Receiver Incremental Tuning (RIT), and speaker level audio volume. The transmit frequency is generated by Ql and its associated components in tbe VFO. The buffer, Q2, isolates the oscillator from the other circuitry to help keep the VFO stable. Q3 builds up tbe signal to a more usable level. The driver, Q4, amplifies the signal. The final, Q5, amplifies it to the 3-W level.


Qrp-cw-transceiver
Click here to download the full size of the above Circuit.

Key tbe transmitter by turning the power to tbe driver on and off, using Q6 as a switching transistor. Select tbe frequency by varying tbe tuning capacitor, C2. The VFO frequency feeds into the diode-ring mixer, and is mixed with the incoming 7-or 10-MHz signal. The difference, or produce, is the audio frequency. The post-mixer circuitry amplifies tbe audio signal to speaker level: Q8 preamplifies the signal a little, U2 is an audio filter tbat attenuates the audio signals above about 700Hz, and U3 amplifies tbe signal from the audio filter to listening level.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Composite Video titling Generator
Lie detector
60 watt 2n3055 power amplifier
Differential Equations
Head light timer circuit
fogger timer
Shock alarm circuit
BA1404 FM Stereo modulator circuit design electronic project
Atmel 89C2051 In-Circuit Programmer
Fridge Door Alarm Schematic 2nd Version
Interactive Toy Traffic Lights
Test circuit diagram with feedback factor of 1 83 DA6101Q 6111Q
Lift control circuit attached to the wall



Top