Detecting wireless cameras

[Sizor]

Hi, I would like to build a simple device that can detec wireless cameras that emit freequencies between 1mhz & 3ghz.

Can anyone please provide a schematic?

Thank you in advance...

 

[Rajaneesh]

Hi, I would like to build a simple device that can detec wireless cameras that emit freequencies between 1mhz & 3ghz.

Can anyone please provide a schematic?

Thank you in advance...

Seems to be like...you wanted to find the hidden cams....!!!!!!

 

[Birdman Adam]

From what I understand detecting a video signal in that whole range would be hard to design and build. You would also have problems discriminating between things like wifi or television signals and actual hidden cameras. Almost all cameras that can be bought at video-surveillance and 'spy sites' are in the 2.4, 1.2, or 5.8 GHz range.
If you want to locate cameras in a room, you would be better off using something like this: Mini Hidden Camera Detector
Other frequencies in the range you suggested would be used by law enforcement. I would consult police or PI if you think your being watched!

EDIT:
Just found this site - **broken link removed**

 

[Dick Cappels]

The first one of these would probably be the best but or wireless camera detector. Also, just search the web for "Field Strength Meter" and "Field Strength Detector" for other ideas.

A Field Strength Meter Using A Biased Schottky Detector
Field_Strength_Meter_FSM_With_Schottky_Detector

Digital RF Field Strength Indicator
a

A Field Strength Indicator -Analog only
analogfsi

RF Field Strength Probe
a

 

[Sizor]

Birdman Adam, a friend of mine travels a lot for work and sleeps in hotels. Someone said to them that some hotels have hidden cams and now they are scared to even take a shower!!!!!!!!!!!!!!!!!!!!!

The reason I pointed out does frequencies is because when I searched the net I found some devices that scan for that range like the The Chinavision CMVM-J19 spy camera and Wi-Fi detector, I had no clue that law enforcement use that range. I taught I can build something similar for them. Thanks for the links, very interesting stuff, much appreciated.

Dick Cappels, this is amazing!!! I was just reading up on transmitting and receiving signals and your suggestion for a strength meter is fantastic!!! Seems pretty simple and straight forward. I will look into it and let you know how it goes.

A few weeks ago I started reading up on Electrical Engineering because I would like to get a bachelor in telecommunications, so please bare with me if I sometimes don't use the correct terms. I also taught that this might be a good experiment for me to see if I really want to get into this field.

I have a question for you, lets say I would want to countermeasure a specific signal. I would use the "Field Strength Meter" to read the frequency strength and then use a transmitter based on the frequency that was picked up to emit a signal creating destructive interference?

Does that make any sense? If so, can you please steer me towards schematics on building this transmitter.

Would it also be possible to build a transceiver incorporating both devices in one? I would obviously start by learning how to build them individually and eventually incorporate them together if that is possible.

This is great exercise for the brain muscles, I really like this.

Thank you for all your help

 

[Birdman Adam]

I do think about things like that sometimes in places like hotels... Maybe I will build one of those FSMs so I can be sure. I'm pretty sure it's illegal to voice or video record or secretly listen to someone unless you tell them about it. But many covert devices can be bought very easily from so called "spy superstores" and set up by almost anyone. Anyone seen the movie Enemy of The State?

Heres a kit from Adafruit. It seems to self-tune itself with dual PLL to block transmissions like bluetooth, wifi, cell phones and cordless phones, plus much more.
Wave Bubble
Not sure whether this would work for you but its very documented and sounds like a fun build! Plus you can easily hide it in your pocket as a cig box. I would love to use this in movie theatre to stop people talking on the phone!

**broken link removed**

 

[Dick Cappels]

I think I recognize the device in the picture above as a pocket-sized cell phone jammer. Just the kind of thing you might wish you had when the guy at the restaurant table next to you keeps jabbering away about his prostate problem while you are trying to have a relaxing dinner.

Sizor, if, by "destructive interference" you mean sending out a signal that will cancel the out the RF signal arriving at the receiver, it doesn't sound very practical unless you know exactly where the transmitter and receiver are with respect to one-another. Reflections and intervening dialectric materials can make thing hopeless real fast.

If you mean to make a jammer, consider that they are only legal in certain circumstances in some parts of the world, and for the use you intend, it is highly unlikely to be legal anywhere in the world.

 

[Sizor]

Dick, thanks for mentioning that jamming is illegal, I didn't know! As I mentioned earlier I am just learning and I surely don't intend on doing anything illegal, just want to work on something simple that will help me get a feel for the discipline so it can be easier once I start class.

I asked the question about "destructive interference" because I read up on "constructive and destructive interference" and taught it might have been interesting in trying to cancel out the RF signal. I will probably try this at a later date as I will know where both the receiver & transmitter will be located, I will set them up myself for learning purposes.

Is there a difference between canceling out a signal and jamming it? If so, what is the difference?

For now I will attempt to develop a "Field Strength Meter" you referred me to, great site , BTW are does illegal?

Also, do you gentlemen know any other docs or sites I can visit that will help me understand RF signals, waves & electronics? Or any suggestions on what can be a good start for a newbie like me?

Thanks again

 

[Dick Cappels]

I don't know of any laws that prohibit field strength meters, but every jurisdiction has its own laws (by definition) so you never know until you check. The reason its usually against the law to jam radio communications is because organization are licensed by their government to use those frequencies, and the government tries to protect the rights granted in those licenses.

Actually, now that you mention it, you can cancel some electric and magnetic fields, as we have done in CRT displays for about 15 years, but in that case, the cancellation signal is generated in close vicinity to the signal source and the frequencies are in the tens of kilohertz rather than the hundreds of megahertz. (Seyno Sluyterman holds the basic patent for magnetic field cancellation and I hold the basic patent for electric field cancellation in CRT displays).

I think that the internet is your best source of information about RF. There are plenty of books, but frankly speaking (writing), they are not as "lively" and current as some websites. One of my favorites is Harry Lythall's Homebrew pages Harry's Homebrew Homepage Another exellent place is the pages of Kazuhiro Sunamura, a Japanese mechanical engineer who has posted many wonderfully illustrated projects, both simple and complex at **broken link removed**

Of course, feel free to email me with any questions that you think I might be able to answer at the email address on my website.

 

[gary350]

If you can not build a detector then build an EMP.

Make a pancake coil 5" diameter by 1/4" thick about 1000 turns of #24 enamel coated copper wire. Paint the coil with polyurethane.

You need a capacitor or cap bank 10,000. up 200 VDC.

You need a power supply to charge the capacitor from 120 volts AC to 170 volts DC.

You can also use a photo flash unit from a throw away camera to charge the capacitor using a 1.5 volt size D battery.

Charge the capacitor then discharge it through the coil. The coil will produce an EMP that will distroy a cell phone and many other electronic devices if it is within 3 ft of the coil.

If you think there may be a hidden camera then use the EMP to distroy the camera. Zap and its dead. Nice thing about an EMP it is not legally a jammer so it is 100% legal.

I know a few things about spy cameras. It depends on the camera but if it is a cheap thing then you can find it with a field strength meter. Some of the top secret high tech stuff the department of defence uses stores information in a zip file. When the file is full it transmits the zip file in a micro second. Even if you have a listing device tuned in to the correct frequency the transmitted zip file sounds like static, just a tiny little click every so often. A spectrum analizer can be used to find high tech bugs.

 

[kchriste]

I would use the field strength meter to locate the camera and disable it by covering the lens with something. Maybe even take the camera if you were really PO'd.
I doubt that the EMP pulse thing would work, and if it did what about the TV in the room? The phone? Your own stuff?

 

[Dick Cappels]

...and remember to take off your watch...

 

[gary350]

The EMP has a range of 3 ft. Anything is the room is fine as long as it is more than 3 ft away. Anything within 3 ft will permently die.

 

[Dick Cappels]

That's pretty precise.

 

[Sizor]

gary350, when you say that anything within 3 ft of the EMP will permanently die, does this also include living species, like humans??? Not familiar with EMP's!

Can you please tell me if this type of Software can do the job? Download OscilloMeter - Spectrum Analyzer 4.14 Free Trial : Real-time OscilloScope + Spectrum Analyzer. : My Music Tools

If so, what data should I be looking for in the Multi Meter?

Thanks

 

[gary350]

EMP = Electro Magnetic Pulse

A large magnetic field pulse causes semiconductors to produce a high voltage inside themself that makes them burn themself out.

Electromagnetic pulse - Wikipedia, the free encyclopedia

 

[bharathionic]

Sir,
can the circuits provided are able to find the frequency range of about 4.2 GHz?

 

[electroyas]

EMP i like that idea , but i dont think it will destroy it if it is covered by metal , apart from that it will destroy expensive equipment like lcd tv and smart phones in range. I think best thing is the field strength meter. If there is a detection then there should be some kind of a wireless device, definitly spy if its inside some book shelf or hole in the wall.

 

[KeepItSimpleStupid]

I think I recognize the device in the picture above as a pocket-sized cell phone jammer. Just the kind of thing you might wish you had when the guy at the restaurant table next to you keeps jabbering away about his prostate problem while you are trying to have a relaxing dinner.

Aside: Your supposed to yell "Honey, get off the phone and come to bed".

 

[unclejed613]

so called "EMP" devices are severely limited in their effectiveness by the inverse square law (field strength decreases proportional to the inverse square of the distance). also in the pancake coil device somebody described above, there's a lot of wire resistance, which reduces the current spike from the capacitors. the US Air Force's EMP test stand had a peak power 0.2TW (200GW), the EMP simulator required close proximity to the airframe being tested. that's a lot of energy, and if the requirement is portability, even your best efforts charging a device from a 15 or 20A wall outlet will fall far short of anything useful.

on a lighter note, this thread has been nominated for a "Marvin the Martian" award, pending decision of the judges......