KEMO Ultrasonic Power Cannon Building Block

does not work on dogs, cats at all, they barely flinch. probably need to hook it up to a high power amp with high capacity tweeters, then should work.

1. BUY THE RIGHT PIEZO speaker. I can't say that enough times. 2. Yes, it's a .5s burst every 5s. So buy more than one, and stagger them! Yeah it might get expensive. But what do you want? Something that works, or another gadget that doesn't? I have 3 of them now and I run them staggered; this isn't hard if you know how. I don't want to add any more for fear the cannon will get heavy, but that's probably unjustified. What really gets heavy is the battery pack, although LiPo's work and... google is your friend. I'm not going to give a tutorial, again google is your friend. They're hooked up to a pair of the piezos that I have in my "double barrel" shotgun made of 1" PVC piping. The extra set of electronics/passives and the amps themselves are in the "magazine." I use it to shut up a dog that's about 200 meters away. It works EVERY time. the dog will run around to the other side of their barn and stay there for at least an hour. On the other side of my property is another pair of dogs- a Marmaduke dog and a bulldog, both very stupid animals. It takes a few rounds to get them to leave, but they do. Works every time. (I'm a dog lover, btw, so don't get all wierd on me. (I have two myself but they come when they're called and shut up when I do call them. So this is really about the owners, not the dogs.) The cannon will also work on a variety of other animals, too. Birds, for example. Specifically, chickens- including roosters. But it doesn't last long and it can't be used too often; they get used to it pretty quick. It WILL scare wild birds away though. This rig is not for the noob. Know what you're doing and it'll work. Last little comment: you absolutely MUST use the right speaker for this thing. MANDATORY. The last one I bought came with the right speaker; the company must've gotten wise to this. Don't listen to anyone who says the thing doesn't work, I'd bet it's because they got the wrong speaker for it. (Yeah yeah ask me how I know.) Anyway, 5 stars because it's awesome, with 3 for ease of use/sturdiness and 4 for value.

Works great...the mutt next door starts frantically yipping and trying to get inside its' house!

I bought two of these to make sound cannons. The units get 13V in but only puts out 2.7VAC to the speaker. So, I took my cannon, pointed it at two dogs 10 feet away, applied the power at 13V and nothing. The dogs didn't even turn their heads. So I ask, Is this high power pulse generator actually working? Considering it only sounds off for .5seconds every 5 seconds seems rather pointless in deterring animals or scaring away dogs. 1/2 second of sound is a bleep in an animals audio world. Update: I was able to record the sound cannon (unable to upload audio files on amazon) in my home studio using a Rodes NT1000 powered condenser microphone. It generated a tone pulse every 5 seconds at 26Khz. It was then transferred to Melodyne and I manipulated the frequency so I could hear it. My conclusion is this is not going to scare any domestic animal. In fact I tried it on the neighbors cat and he only turned his head to look. Do not but this to keep barking dogs quiet. Use Kemos adjustable generator and piezo tweeter, so you can dial in a frequency that the animal hates, then broadcast it continuously.

It works as advertised...first time. The photo shows Rev 1 of my project. The oscillator only has the one frequency and its usefulness is limited. I added a USB port to power an external oscillator with its own amplifier that is variable and can run on the same battery. The speaker is in a caulking tube attached to its plunger so I can place it in differing places based on frequency/wavelength. Practical? Useful? It's clunky, over engineered, and not very practical. It was designed on the fly and was a LOT of fun making it. The overdesigning of Rev 2 is in underway. It will have double barrels and 2 seperate Kemo oscillators operating independently and on different frequecies. The variable ones are much more useful and less clunky since they can live onboard.

work well, has been keeping dogs away for over a year, runs 24/7

It does not work. I don't think it even puts out a signal. The animals (dogs and cats) I tried it on just looked at me with a blank expression. I hooked it up to an output meter and no signal was registered. Next time I will hook it up to an oscilloscope to see what kind of signal if any it is putting out.

I really wanted to like this product. I would have been happy if it was either ultrasonic or high powered (preferably both). The one I received was actually 11,500 Hz and ~50 db. I can confirm it does buzz for 0.5 sec every 5 seconds. Didn't bother my cats at all, who were lounging around the house.