Öz This paper introduces a new adaptive data transmission rate measurement system for wireless HF digital communication. The system automatically detects and displays the transmission rate of digital data in the presence of FSK modulated signals. For that purpose, a digital phase locked loop (DPLL) and a microprocessor with its peripheral components are used in order to measure the data rates of the digital signals sensed through a receiver and an antenna. After the system is locked to the input frequency, the software ran by microprocessor measures the data transmission rate of captured signal within a limited nurnber of data sequence. The detection and the measurement range of the data rate is between 45 Baud and 52000 Baud according to the available standards. The experimental results show that the data rate measurement system can reliably be applied to a communication system whenever the data rate is required for establishing a first connection successfully.