3 KILOBAUD FULL DUPLEX FSK MODEM
The circuit described involves a frequency-shift keying (FSK) communication system that operates within a specified bandwidth of 13 kHz. The mark and space frequencies are set at 1070 Hz and 1270 Hz, respectively. This modulation scheme allows for the transmission of digital signals over an analog medium, making it suitable for various communication applications.
The Exar XR-2206 function generator is employed to produce the required frequency signals. This versatile component can generate sine, square, triangular, and sawtooth waveforms, ensuring that the output can be tailored to meet the specific requirements of the FSK modulation. The XR-2211 FSK demodulator, on the other hand, is responsible for decoding the modulated signals back into their original digital form. It effectively detects the frequency changes in the incoming signal, allowing for accurate data recovery.
The power supply for this circuit is designed to operate at voltages below 12 V, providing flexibility in terms of power source selection. This is particularly advantageous in portable or battery-operated applications where minimizing power consumption is critical.
The design procedure outlined in the report serves as a guide for engineers looking to implement similar systems. It likely encompasses component selection, circuit layout considerations, and calibration processes to ensure optimal performance of the FSK communication system. The reference to the "Phase-Locked Loop Data Book" indicates that additional theoretical background and practical examples are available for those interested in further exploring phase-locked loop technology and its applications in frequency modulation and demodulation.Values shown are for 13-kHz bandwidth 1070 Hz for mark and 1270 Hz for space, using Exar XR-2206 function generator and XR-2211 FSK de-modulator Report gives design procedure Supply can be ‹12 v "Phase-Locked Loop Data Book, "Exar Integrated Systems, Sunnyvale, CA, 1978, p 57 61. 🔗 External reference
Related Circuits
The Full-Cup Detector utilizes a 555 oscillator/timer configured to generate a 15 Hz clicking sound until its probe contacts are bridged. At that point, the output frequency increases to approximately 500 Hz. This device is designed to assist visually...
A highly effective application of the 565 Phase-Locked Loop (PLL) is its use as a Frequency Shift Keying (FSK) demodulator. In the 565 PLL, frequency shifting is typically achieved by driving a Voltage-Controlled Oscillator (VCO) with a binary data...
The adjustment potentiometer RP can modify the charging current. The adjustment potentiometer, designated as RP, serves a critical role in regulating the charging current within an electronic circuit. This component is typically a variable resistor that allows for fine-tuning of...
This design enables the operation of two intercom stations, allowing the operator to remain hands-free for other tasks, thus eliminating the typical push-to-talk operation mode. No complex changeover switching is necessary; the two units are interconnected using a thin...
The TBA120U is an intermediate frequency (IF) amplifier that includes a symmetrical frequency modulation (FM) demodulator and an audio frequency (AF) amplifier with adjustable output voltage. The AF amplifier features an output for volume control and an input for...
This circuit employs an 87C57 microcontroller along with several peripherals to convert X-10 power-line carrier-code formats from a personal computer for use with an X-10 power-line interface in a home-control system. Software details can be found in the reference. The...