The ETB-263 Modulator and Demodulator Trainer is a comprehensive educational tool designed to study four fundamental digital modulation techniques: Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Binary Phase Shift Keying (BPSK), and Differential Binary Phase Shift Keying (DBPSK). It provides both modulation and demodulation circuits for each technique, allowing hands-on experimentation and comparative analysis. Suitable for digital communication labs, this model helps students grasp key modulation concepts, signal waveforms, bit error rates, and noise effects.