... YB1620 · Digital Frequency counter · Linear/Log Sweep Frequency Function · External FM VCF Input · TTL/CMOS Output · Sine, Square,Triangle, Ramp, Pulse ... ~20MHz·Output Wave: Sin,Triangle,Puls,Ramp·Signal Type: single,FM,AM,Sweep·Sweep Type: Linear,Log·Sweep Rate: 5s~10ms·Output ...