How To: Hack a Radio to Pick Up Different Frequencies - Including Law Enforcement & More

Hack a Radio to Pick Up Different Frequencies - Including Law Enforcement & More

Hardware hacks are something I feel we don't get enough of at Null Byte, so today I figured I would introduce a fun one. I've always been a curious hardware hacker. Taking things apart and learning how their internals work has always been a part of my nature. Quite some years ago, my father showed me a really cool trick on how to hack normal radios to scan frequencies that are normally non-listenable. This little hack allowed us to scan frequencies belonging to law enforcement, and even frequencies that the town fair had used to make announcements over a loudspeaker.

To have fun with this cool hack, we're going to need a few things.

Note: I'm not sure if this works on all radios. I haven't tried it on anything other than 3 cheap radios from Wal-Mart. I would imagine that all radios work the same, so in theory, this should be possible with any radio.

Requirements

  • A cheap, disposable radio
  • A Philips-head screwdriver

Step 1 Pop Open the Radio

First, let's take apart the radio so that we can get to its internals. You need to remove all of the screws necessary to get the case completely separated. Depending on the radio model, this may mean that you need to remove all of the screws.

How to Hack a Radio to Pick Up Different Frequencies - Including Law Enforcement & More

Step 2 Hack the Tuner

Radios change which station they're listening to by adjusting a small, copper-looking wire coiled around a cylinder. When adjusted, the gaps between the coils in the copper wire become tighter or more separated depending on how the tuner knob is adjusted.

In order to hack your radio, here's what you need to do:

  1. Turn the tuning knob on the outside of the radio.
  2. Observe the mechanism connected to the tuning knob on the inside of the radio, while continuing to turn the knob. This will lead to your wire and cylinder that controls what frequency the radio is scanning.
  3. Turn the radio on. If it doesn't turn on, make sure everything is connected properly.
  4. Turn the volume up.
  5. Pull and separate the wire that is on the cylinder. You should hear the static shift and warp, this means you are changing stations. Adjust the coil until you start hearing human-related sounds from the speakers.
  6. Congratulations! You are listening to a broadcast that isn't supposed to be a broadcast.

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9 Comments

I usually do this with Wunder Radio on my iPod, but I had no idea you could do this on a real radio!

Not sure which century this how-to was written in, but looking at the photo accompanying it I would guess towards the end of WWII. Most new and cheap radio receivers do not use capacitive/inductive resonator circuits you can toy with. Oh and by the way even if you can hack the cheap radio to receive in a higher or lower band, there is nothing interesting to listen to anymore as mobile phones, cordless phones, baby monitors, public safety and commercial broadcasts have either gone digital or are transmitting at microwave frequencies your hacked little radio just cannot get to, even if you hit it with a hammer. So, rather spend your money on a cheap radio scanner (also available at Wal-Mart) with which you can listen to many, many interesting things without having to hack anything.

Yeah, but this was just for fun, just to show people it's possible, nothing more :D. Police scanners are cheap nowadays, and hacking cell phones isn't exactly hard via bluetooth. A friend I have has actually inspired me to attempt to write a Linux driver for a PCIe, large spectrum radio antennae. Imagine the fun that could happen with that? Haha. Got a bit more ASM before I'm ready for that, though...

Sorry did not mean to sound critical. From your comment I deduct you want to sample (A/D) RF directly into your computer so you can do the demodulation and filtering digitally. In the world of DIY radio, Software Defined Radio (SDR for short) is all the rage these days. You can buy them commercially, in kit form or build e'm from scratch. For less than a cheap wall-mart radio you can buy a Softrock SDR kit and get into the game (http://www.wb5rvz.com/)

That's so awesome, thanks :) I got a new project to work on soon now, haha.

please tell me how i hack police radio conversation via my cell phone (huawei ideos) by using radio of my cell phone or some thing else

please call me and tell me how I can put the frequency for my Autopage car alarm remote control into my personal smartphone to work it from my cell phone instead of using my Autopage remote control 323 241 8705

I know there has to be a way to recognize the signal from my cell phone to my remote control unit from my car to record the frequency to make it work

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