Abstract: An improved EEG system (10) for telemetrically transmitting brain activity data from a portable transmitter to a processing console. The improved EEG system (10) includes a lightweight transmitter (12) which amplifies and digitizes the EEG signals from a set of electrodes (16) and transmits the digital signals along with a checksum to a receiver (14). The transmitter (12) may be carried by the subject under observation. The transmitter (12) of the preferred embodiment includes at least four circuit boards including a selectively interchangeable montage board (18), an amplifier board (24), a processor board (34), and a transmitter board (54). A signal is transmitted toward the receiver (14) and delivered to a conventional computer-controlled broadcast television tuner (80). The selected receiver (14) outputs data which is in an acceptable form for connection to standard microprocessor peripherals.