Super-Simple Shortwave Receiver Circuit


Posted on Oct 6, 2012

Integrated circuit Ul (an NE602 double-balanced mixer) is a combination oscillator and frequency mixer. Signals from the antenna input (at Jl) are fed through dc-blocking capacitor C1 to the RF-gain control, Rl, and fed to the input of Ul at pins 1 and 2. The local-oscillator frequency, which varies with the settings of R2 and L2, is mixed internally within Ul, resulting in an output. The mixer output at pin 4 of Ul is applied to a tunable 260-kHz band-pass intermediate-frequency (IF) transformer, L3, tlirough dc-blocking capacitor C7.


Super-Simple Shortwave Receiver Circuit
Click here to download the full size of the above Circuit.

Therefore, signals that are roughly 260 kHz above and below the local-oscillator frequency are passed while others are effectively blocked. The IF frequencies are now amplified by Q2 and Q3. The AM audio signal is detected by D2 and its associated components, which bypass the RF signals, and leave only the audio signals. The signals are preamplified by Ul -a (half of an LM358 dual op amp). The audio is then boosted to speaker level by the LM386 low-voltage audio power amplifier, U3.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

TDA 7053 Stereo Audio Amplifier Circuit
Laser Communication (Transmitter
microcontroller Arduino 230v Light bulb dimming
Full bridge class d amp using 555 timer
tone control circuit designed
555 Timer as Monostable Multivibrator
Audio Power Amplifier 60W with TDA7294 circuit
arm7 slicker article
Yaesu FT-736R AGC
HP 200LX USB / Power Supply dongle
UNIVERSAL BATTERY CHARGER
Accelerate the role of capacitance



Top