Inquiry About Your DIY Ultrasonic Microphone Jammer Project

[oussamaCH20193]

Dear JustAnEngineer,

I hope you are doing well.

First of all, I want to sincerely thank you for sharing your work and knowledge. I truly admire your projects and the way you explain them. Your content has been a great source of inspiration for me, as I am very passionate about electronics and signal processing.

Allow me to introduce myself: My name is Oussama Charef, and I am a young engineer from Algeria specializing in networks and telecommunications. I recently followed your video on the "DIY Ultrasonic Microphone Recording Jammer for Android and iPhone" and built my own version, designing a custom PCB. The jammer works quite well on most devices, but I’ve encountered two challenges:

A slight audible hissing sound coming from the ultrasonic emitters.
Reduced effectiveness on recent iPhones: It seems that at a distance of 10 to 15 cm, iPhones are able to detect and filter the ultrasonic signals, making the jammer less effective.
I was wondering if you have encountered similar issues and if there might be a way to optimize the design or modify the code to improve its efficiency, particularly against iPhones.

I have attached images of my prototype and PCB design for reference. I would be truly grateful for any advice or insights you could share.

Thank you again for your amazing work—I really appreciate the time and effort you put into your projects! Looking forward to your response.

Best regards,
Oussama Charef

ge](https://github.com/user-attachments/assets/ec37aac1-ef28-4617-b4f9-f9346c0ad4bf)

[jellyzily]

hello im a student from china, i want to know what u use ,linux or windows,because i can't use linux,i can't use the code. i need your help..My English is not very good. Please excuse me. Here I offer my best wishes to you.

[jellyzily]

joely7144@gmail.com and 2738292695@qq.com are all my email,if u can see my comment and have time to help me,u can touch me,thank you,best wish to you,and look forward to your reply

[mcore1976]

Hello Oussama ,

I see you have used additional coils and IRF MOSFET which in result will enable higher voltage on ultrasonic transducers therefore higher power will be emitted. IRF serves as additional "voltage key" and is not mandatory. You may play with higher inductance values, I know it has a slightly better effect especially on iPhones, however it may generate noticable sound at some point. Also you may want to put variable resistor instead of to fixed resistors to be able to change the signal shape.

Also please swap the diode to something more powerful like 1N400X to sustain more voltage and current. 1N4148 is just not enough :
https://github.com/mcore1976/antispy-jammer/blob/main/mic-jammer-AD9833-TPA3116D2-IRF-coils.png

I think you need some holes in this plastic case, because the components will eventually get hot and may break.