I knew a guy that was a radar guru with a local defense contractor.
He said the early police radars were not filtered to prevent a huge return signal burning them up.
He said it was amusing to watch the police officer as he passed banging the radar gun with his hand wondering why it quit. Or why it was smoking.
He said he could tell when the unit triggered because the headlights dimmed.
Fresh out of school I worked for a wholesale electronics firm that sold (among other things) CB radios and accessories and radar detectors. The jammer I bought was “advertised” (word of mouth) as a radar detector tester. It was supposed to be something that you could use as a sales and technical tool to verify that a detector was capable of triggering an alarm upon reception of the radar wave transmission.
The funny thing was that it came with a cigarette lighter plug for power and had sunvisor clips on it. That made it perfect to set side by side with my own detector in my van.
I would be tooling down the highway at 75 (I can’t drive 55 ;’) and a Porsche would come up on me like I was standing still. Hit the jammer for a second or two and the other car would immediately hit the brakes and wildly look for the cop. Sometimes I would use it on cops in the speed traps. I’d find a vantage point where I could watch him but he wouldn’t know I was there. When he would start flashing cars (I would know because my own detector would go off) I’d hit the detector. I know that I frustrated the crap outta a bunch of cops who never did catch on to what I was doing ;’)