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			| Microwave Detectors - 
		Amplifiers - Radar Circuits
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							| Build your own cable radar:  
							10/01/98 Electronic Design - Ideas for Design /  
							A time domain reflectometer (TDR) is a handy but 
							rather expensive instrument, and isn’t commonly 
							found on every bench. I used to rent them, but after 
							having paid large bills for several years, I decided 
							to make my own. I saved a bundle and was able to. . 
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							| Digital Radar Speedometer: |  
							| Economy radar detector 
							:  This circuit uses a 1458 dual 
							op-amp to form a radar detector. C1 is the detector 
							of the radar signal. The first op-amp forms a 
							current-to-voltage converter and the second op-amp 
							buffers the output to drive the piezo transducer. R5 
							sets the switching threshold of the second op-amp; 
							normally it is adjusted so that the circuit barely 
							triggers on background noise, then it's backed off a 
							bit. The response of the circuit may be tuned by 
							adjusting the length of the leads on C1. For typical 
							road-radar systems, the input capacitor's leads 
							should be about 0.5 to 0.6 inches long. |  
							| "Radio-Electronics" Magazine, Jul,86 issue (C) 
							Copyright Gernsback Publications, Inc.,1986 |  |  |  
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