Robie Jr ultrasonic signals

Using the Bitscope on the Robie Jr Ultrasonic control shows these wave forms. Measurements were taken from CN1 at pins 4 and 5 on the OKI M6411b-24 IC.

Signal time ~25 ms

Time between signals ~98 ms

Not sure why the signal is so fuzzy? Is it the 30 year old electrolytic caps? Is the signal similar to an IR signal? When using the logic analyzer I seem to get different packets every time. Will continue pondering...