KEMO Ultrasonic Signal Generator Module, Push Button Switch, Rotary Actuator, Automatic Operation, Black

I have tried every device under the sun to stop my neighbor's dogs from barking...the 9V handheld units, the rechargeable ones that detect barking, even spent $150 on the "Good Life" unit. Nothing worked, at least not in the long term.I bought two of these frequency generators, two L001 Kemo tweeters, a large unfinished pine box with lid 11.4"x11.4"x8.25", a BN-LINK remote control plug outlet, and a Chanzon 12volt-1amp-12watt household plug outlet to power everything (all from Amazon). I wanted 2 frequency generators to run at different frequencies for maximum effectiveness.I cut the rectangles out for the tweeters using a wood router and soldered the speaker wire to the speakers and just used electrical butt connectors for everything else. If you don't have these tools you can find everything you need on Amazon. You'll just have to watch some youtube videos on how to use a router, a soldering iron, and how to crimp on electrical connectors...or you could just pay someone on Craigslist to build this box for you, most handymen can easily do it.When you get the Chanzon plug you will need to cut the end off and strip the wires bare. The one with the small white dashes on it is the ground wire and the other is positive. You will connect them to the frequency generators. I wired the generators in parallel, meaning that both positives went to the Chanzon positive and both negatives went to the Chanzon negative. Wiring the generators to the speakers is easy because it doesn't matter which way you connect them, the polarity can be reversed and the speakers will still work.I used some screws to attach the generators to the inside of the box and then drilled a small hole through the box for the power wire to come through. This box and speakers are not fully weather proof so you will need to keep it under cover as best as possible. I keep it on my patio and point the speakers at the fence. At this point you are ready to plug the Chanzon into the BN-LINK remote control outlet and then plug the BN-LINK into the nearest outlet, I used an extension cord for this last step as I didn't have a plug nearby.I initially started the frequency at 5 on one generator and 6 on the other. I figured this was good enough because I couldn't hear either of them but I am practically deaf lol. Turns out my GF and our kids could hear the frequencies so I turned them up to 7 and 8 and finally everyone said it was completely quiet while turned on.Now, please be aware that there will be a chirp when you power the device up regardless of how high you turn the frequency up but you can't hear the chirp inside your house so no one else will really be able to hear it either unless they are outside when you turn it on. I am not bothered if this happens. My neighbors already know I hate their dogs. As per another Amazon reviewer suggested, I tried to wire in a 10 second timer delay to keep the speakers from putting out any noise until the generators were done chirping but I couldn't figure it out, it is beyond my wiring capabilities apparently.Anyway, the BN-LINK has a blue light on it that illuminates when you power the device on. You won't be able to see it during the day but I can look outside at night and tell if the device is on or off because I forget sometimes when I am training the dogs not to bark. The remote works really well and I can be on my couch in the living room and it will still reach outside even through the wall or glass windows. Maybe up to 25 feet and probably 35 or more outside in direct line of sight.It will take a little bit of time for the dogs to figure out the training. They do not like the machine at all. They often go to the other side of their house when it is on which is fine with me because I can't hear their barking as much over there. They have multiple dogs and each dog will react to different frequencies and this is why you might want two generators like I bought. I carry the remote with me when I take the trash out or if I am mowing the yard. They are starting to learn to avoid me like the plague. It is not a perfect scenario but it has improved a lot! I was literally ready to pack up and move but at this point I might be able to tolerate them a little longer. Good luck with your own doggy troubles! Best wishes.

Nice adjustable pitch

This sweeps in frequency every one second or so, about 20% of the band.at setting of 10, low frequency will be 32kHz, high frequency will be 40kHz.unloaded (not attached to speaker), voltage out is +-10V square wave.works down to power supply of 5VDC.i'm returning because i wanted a steady tone,otherwise operation is simple, construction looks good, case is potted from back side.

This was the working core of my design to stop two big dogs barking from my idiot back yard neighbors. I already knew from my other neighbors that had been suffering for years that there was no use talking to them and they had no intention of trying to train them or fix the problem. So as a tech I knew this could help. Although I was skeptical because these dogs were big and loud...I wasn't sure if this would have any effect on them.I bought this unit but its actually a little different than what is pictured. Its actually a bit newer looking and smaller in design. The knob is smaller and the back sealed with epoxy. Very solid.In response to other reviews, I want to say this. If you over power your speakers or your amp cannot handle the proper line input or frequency range of the generator then your will more than likely run into problems. Thus blowing out something and causing failure.My design included an amp with a proper resistor network in front of that with 2 high power peizo speakers custom mounted into tubes to make cannons. I also used an RF remote to turn it on. Since this was a stealth design I did notice when you turn the unit on, you actually will hear the generator "ramp up" from the lowest to the higher frequency which takes only about a second but still you can hear it. So to remedy that problem, I simply put a 555 timer relay on the final output line to the speaker. So when you turn the whole thing on, the speakers get connected 2 seconds later after the generator is "booted up" and at the proper frequency that you cannot hear.The final result was pretty good. It takes time though as it wont immediately stop all dogs from barking. You have to train them, every time you hear them dog bark, you turn it on, they stop and you stop. Eventually they will learn and after a couple weeks, its completely different now and Im finally getting peace. No more 6am wake up dog calls and I seem to be the hero of the neighborhood. Fingers crossed it stays like this.I gave it 4/5 stars. It would of been perfect if it had the ability to adjust the power output levels or have a built in amp to save time. Plus the fact it does not turn on at the proper frequency first, instead it has to start at the lowest and go up. Thus needing to add another part to my solution.The frequency dial is not as precise according to the manual and the ranges overlap between numbers so its hard to know exactly where its at.Overall though this is a good unit. It drives the sound well. When you hear it, its like a siren, pulsing in your ears and it is very annoying. The peizos I used also helps as they were pretty good and loud but I think my wife nearly lost her mind on me while I was testing so make sure your alone when you do. That's it for now...good luck out there to anyone dealing with idiots like the ones that live behind me. Hope this helps.

The dogs were not phased one bit either way. I'll probably continue to experiment with it but I will say that the "ramp up" phenomena that other purchasers complain about seemed to be remedied by adding a rocker switch on the speaker side of the circuit. I used the M048N piezo speaker, a 12-15V rechargable Lithium ion battery pack and switch https://www.amazon.com/dp/B0DK52TPSQ?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1 to turn it on / off. I used a simple bread board to plug all the wires into and make the circuit. I think the thing to do is amplify the signal and get a higher wattage piezo speaker. Mixed review here but this thing did work out of the box and does generate some frequencies.

Seems to work for barking dogs. Would recommend and I even bought a 2nd.