Horiz. freq. detector

positronicle

New Member

• Feb 4, 2008

• #1

Does anyone know of a good compact design for detecting the horizontal freq. of the NTSC standard(tv's, camera's, etc)? Thanks all.

 

Last edited: Feb 4, 2008

Nigel Goodwin

Super Moderator

Most Helpful Member

• Feb 5, 2008

• #2

I suggest you give more details of what you're trying to do?.

 

B

Blueteeth

Well-Known Member

• Feb 5, 2008

• #3

Is this what you are looking for?

**broken link removed**

You could use that with a PLL if you wish to know the exact timing.

Blueteeth

 

positronicle

New Member

• Feb 5, 2008

• #4

I'm interested in building a fairly sensitive detector, in order to locate hidden recording devices.

 

M

mneary

New Member

• Feb 5, 2008

• #5

Now that cameras and monitors don't use magnetic deflection, and with the VCR dying, storage is mostly digital, radiation of 15,750 KHz is almost nonexistent.

 

positronicle

New Member

• Feb 5, 2008

• #6

mneary said:

Now that cameras and monitors don't use magnetic deflection, and with the VCR dying, storage is mostly digital, radiation of 15,750 KHz is almost nonexistent.

Click to expand...

I suppose you are right. Then that would bring me to my next question. Does anyone know how well those laser camera(lens) detectors work? I am already equipped to deal with the wireless variety of cameras. The wired ones, seem to be a bit more elusive, though.

 

M

mneary

New Member

• Feb 5, 2008

• #7

A wire leading to a camera or microphone might be detected with an RF antenna scanning the walls, etc. Changes to the radiated pattern would indicate something conductive parallel to the antenna. No help, however, if they are inside an existing conduit or shield.

And now with flash memory, a camera can save pictures for later retrieval.

Oh, and I meant 15,750 Hz.

 

Hero999

Banned

• Feb 6, 2008

• #8

Use an AM radio aerial with the coil rewound and a larger capacitor added so it resonates at 15.7kHz.

Use an amplifier followed by an NE567 tone decoder to light an LED or sound a piezo buzzer when the radiation is detected.