This unit is a bit harder to assemble than a division detector, owing to the fact that it has many more components. The PC board is well done, if a bit cramped. The assembly instructions are clear and an excellent diagram is given. The circuit description genuinely tries to explain how the unit works, and scucceeds. This is indeed a "smart kit"!
Schematic diagram and parts list.
The additional tuning control is a bit intimidating at first, because one doesn't really know where to set it when looking for bats. I detected my firt bats by placing this control in the second quarter of it's range.
sample 1 (2.2 s, 19 kb mp3).
amplitude and frequency plots
The pulse rate is about 10 per second, but the pulse constituent frequency is unknown.
sample 2 (2.2 s, 19 kb mp3).
amplitude and frequency plots.
The pulse rate is about 5 per second, and the pulse frequency appears to be higher than in the previous sample.
As in the case of the division detector, all sound and image processing was done with linux-snd, gimp and bladeenc.