SM-4040 dds Function Generator: 1.40MHz Freq.&wide ... 3.w/AM FM function MCH DDS Function Generator, SM-4040 DDS Function Generator, 40MHz Freq., built-in frequency ... Control modeINT/EXT (External TTL level,F1:low-level,F2:high-level)Phase-shift keyingWaveformsine, squareFrequency range100μHz-20 ... change without prior notice. MCH DDS Function Generator,SM-4040 dds function generator,40MHz frequency w/AM FM ...