Haynes Build Your Own Bat Detector Kit

For quite some time, around the basement, attic & garage, I had some of those "Pest Repellers" that use ultrasonic sound to repel rodents, bats, insects, etc. I was looking for a way to determine if the devices were actually functioning, since the high frequency sound is well beyond human hearing. This ("bare bones--but NOT A TOY") Kit took about 5 minutes to assemble, mainly plug-in connections--turn it on, play with the volume & frequency adjustments to "tune" it, and go test your ultrasonic systems! I am discovering which of my repellers are actually working (my most expensive repeller was not!), how strong their signals are, and the dispersion patterns of the signals in the spaces where the repellers are placed (I haven't had a chance to detect any Bats yet). O.K, the small box the kit comes in serves as the chassis for the electronics, but it's functional--I thought about putting it in a waterproof box and taking it to the beach to listen for dolphins, porpoises or submarines. Just don't throw it in your toolbox or sit on it. It works--I like it--I wish I had found it sooner--and I'll buy it again! It would also make a good Halloween party favor for anyone 14 years and older, if they're into detecting Bats, ultrasonic signals or mechanical noises from high pressure leaks in A/C or water systems, etc.

I bought this for listening to my pet rats ultrasonic vocalizations. It works. There is no numbers in the dials so you have to guess where to set the knob, but it does work.

Lätt att sätta ihop och vi kunde äntligen identifiera den där fladdermusen som flyger runt vårt hus om nätterna.Riktning på micken kunde varit bättre, men överlag en billig rolig sak för att lyssna på fladdermöss.vad jag skulle önska för att ge fem stjärnor är en mer exakt frekvens-inställning.

After using a borrowed bat detector on a night-time walk with our local ranger, I wanted to buy one of my own. The problem is that most are priced in the £80-£120 range. Not too great if it is discarded after a couple of night-time walks!This little kit is much more reasonably priced.Pros:o Does actually worko Excellent value for moneyo Easy to assemble (no soldering, just plug some parts together)o Could relatively easily be transferred to a plastic box if desired.o Built-in loudspeakero Runs on easily obtained 9V batteryCons:o Cardboard enclosure, so not ruggedo Battery not secure in boxo No headphone socketo Frequency is uncalibrated *o Battery not included* Even some of the expensive ones don't have a frequency readout.For the uninitiated: this consists of an ultrasonic microphone and amplifier followed by a mixer. The output of an ultrasonic CW oscillator is mixed with the (amplified) incoming signal to heterodyne it down to audio frequencies. It is then amplified and fed to a loudspeaker.Bats emit short bursts (not continuous shrieks) otherwise they would not hear the echoes coming back. So, as long as the oscillator is roughly in the right range, the bat's call will sound like a click when mixed down anywhere in the audible range. With a calibrated oscillator (which this does not have) you MIGHT be able to identify the type of bat based on the frequency setting - however I suspect that the bat's flight and other characteristics are possibly more telling anyway.

Super