I was stunned to see this at Wal-Mart. Yep, "Hot Wheels" brand is selling an honest-to-god, 10.525GHz radar gun! Like $30.

It reminds me of Back To The Future II where that amazing, uber-cool hoverboard came in a crappy "Mattel" toy brand, and in pink no less.

Wow. The possibilities... ok I'm not sure what they are, but they've got to be plenty in there somewhere!

This guy's hacked it trying to measure an absolute distance as a rangefinder- difficult though. The transit time is quite low. Also I have to note that the ground and other reflectors are going to provide significant return as well, clouding the signal.

http://www.edparadis.com/radar/

The interface is fairly simple, just a low freq difference signal (I calc like 1100Hz for 100 feet per sec).

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

Neat - I did not realize these were real.

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"Everything that is done in the world is done by hope." -Martin Luther
"There are two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."-Albert Einstein

 

wow, thats pretty cool. It's only $20 at target, but no one has them in stock

I'll have to keep my eyes open for one

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Jeff
To the optimist, the glass is half full.
To the pessimist, the glass is half empty.
To the engineer, the glass is twice as big as it needs to be.

 

I knew they were real, I thought it was ultrasonic not real radar.

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It looks like the Gunn Diode is close enough to the Police X-band that it would have made an interesting "jammer" project 20 years ago.

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--- The days of the digital watch are numbered. ---

 

X-band is 8-12ghz. Modern Gunn Diodes are supposed to be able to form up into the terahertz frequencies when used as a relaxation oscillator, although at that point the physical size of the device is more important, so modern semi conductor manufactoring size is the primary determinate of the maximum frequency, excluding of course primarily the power amplification phase.

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That's why I prefixed it with Police (10.5 to 10.55 GHz). Pretty simple devices; Gunn diode + Microwave diode + audio amp + digital logic = doppler radar gun.

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--- The days of the digital watch are numbered. ---

 

Actually it's not a Gunn diode. It's a transistor Dielectric Resonant Oscillator (whatever that is).

These guys have been hacking it extensively. By itself, it has VERY little range, the transmit power is quite low. Probably due to the need to be cheap and also not cook the heads of kids staring into it.

http://www.austech.info/showthread.php?t=135840&page=1

They replaced the DRO board with a real Gunn diode, upped the voltage with a new battery, and got pretty nice performance!

It's pretty mind-blowing that these are real.

I do have a project in mind where I need to detect not only the velocity of a projectile, but more importantly the change in velocity (in relation to its instantaneous velocity) to calculate its drag coefficient. Doing that would require a Gun diode for range, new processor (no problem) and a new display (probably a serial port for data transfer for display on a laptop).

But now I'm starting to think since I'd throw out the DRO, processor, battery, and display,
is anything left in this device that is worth getting? I'm not clear on what would stay and how hard it would be to make something of my own that did the same job.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

That's like takes a fake gun, cutting out it's innards and glueing a real gun inside =) Stops being a toy at some point!

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