Frequency Division Detector by Tony Messina (It is called The Enhanced Simple Bat Detector). This was the first detector kit that I built (in fact I built several and gave two to a school science program). I was so excited after building this kit that I had to go out every evening and listen to the bats as they flew around our garden. I use this detector often because it is small and sensitive to the bat calls. |
The Belfry Bat Detector (also frequency division but uses a slightly different circuit). This detector has an additional amplifier stage so it has the effect of being very sensitive to the bat calls. |
The Bat Scanner. This detector is a heterodyne type and also features a digital read-out. It will scan the frequency range and stop when it detects a bat, showing the frequency of the bat call you are receiving. Up/down buttons are used for manually selecting the frequency at which you wish to listen to the bats. It is very accurate, sensitive and quiet. The Bat Scanner comes from Tony Messina. |
The Deluxe Bat Detector (another frequency division but again, uses a slightly different circuit) In mine I added a trim pot to the front end op amp feedback so I could tweek the gain to its maximum. This one comes from Electronic Goldmine. |
Bat Chirp is another great product of Tony Messina. It does the work of my "Bat Amigo", only better. Bat Chirp emits a constant 40KHz signal, a series of bat-like chirps, and a sequence of chirps that sound like a bat flying by. |
The Ultrasonic Translator is a heterodyne circuit from Transtronics that came as a very inexpensive kit. It was easy to build and performs quite well even with some background noise. I installed the transducer in a PVC pipe fitting and put a jack on the side to plug it in. Also, I put in a headphone jack and a switch to select between the headphones and the internal speaker. Unfortunately, I think this kit is no longer available. |
Thanks for your visit. If you have any comments or questions, please e-mail: wolfden@terragon.com