Radio Beacon Converter


Posted on Aug 21, 2012

The radio beacon band extends from 280 to 516 kHz. Each beacon has its own characteristic AM`-modulated morse-coded


Radio Beacon Converter
Click here to download the full size of the above Circuit.

callsign that is transmitted on a specific frequency. To be able to receive distant beacons, the aerial signal is passed through a band-pass filter that effectively suppresses longwave and mediumwave signals. The filter also converts the aerial impedance, Zm, from about 10 KOhmhm to the input impedance of mixer IC1, which is about 1 KOhmhm. The mixer adds or subtracts the received signal to/from the local oscillator signal so that the beacon signal can be received on a normal shortwave receiver. The resulting frequencies are from 9.72 to 9.48 MHz or from 10.280 to 10.516 MHz. In the construction of the converter, some components must be surrounded by a metal shield, as indicated by dashed lines on the PC board layout. The circuit is aligned with the aid of an SSB receiver, to which the output of the converter is connected. Tune the receiver to 10 MHz and adjust the oscillator frequency of the converter with C8 for zero beat. Next, detune the receiver slightly until you hear a pleasant whistle, which is adjusted for minimum level with the aid of PI. Finally, tune to a beacon transmitting at or about 300 kHz and adjust C13 for maximum sound output.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Low power temperature controller
DIY GPS Jammer
Tube Preamplifier with ECC88
Decade resistor box
9 V NiCd or NiMH accumulator charger
Basic-track-and-hold-sample-and-hold
5W 7Mhz Rf Power Amplifier Circuit
Another RF Field Strength Meter
Geiger Counter
Noise Suppression For R/C Receivers
Infrared proximity sensor serial Si1143 of Silicon Labs Company
100w inverter
Long range FM transmitter
gmcounter
Easy Auto power battery charging circuit
Ten-segment frequency equalizer



Top