Wanting to test home built lidar jammer

[Swamp]

I gather that your pulse generator is a resistor-capacitor timing circuit with the TO-92's handling swiching duties to trigger the jammer (er, excuse me, transponder) and I'm wondering why not use a 555 or 556?

I use them a fair bit to make adjustable PWM type circuits; by using a 556 I can have one section generating a frequency that is adjustable via a pot which feeds into the trigger on the second section which ouputs an adjustable pulse width also adjustable with a pot.

PS, Cool Project!

[Solion]

The premise is to make this as simple and easy a build as possible, Sadly Radio shack is not the store it once was and getting ahold of a 555 timers and such tends to put people off , But I do see your point.

But yeah , this is just a pair of 2n4401's with a third to give me my negative pulse to pull down the FET. This unit is the home made JAm -- Um , transponder portion of the system. I will be testing tomorrow to see if a 2khz pulse rate will jam with the heads I built. so there are two sides to this first, can offboard heads be added to a blinder, and second will the 2khz square wave generator jam a gun with the heads I built.


If the 2khz generator works, I will be connecting it to a elcheapo radar/laser detector. I hacked the LASER LED inside it to drive a transistor to flip the square wave generator on.

All in all. for about 40.00 you can build the Ja...transponder portion of this with the IR leds

Do I expect it to throw a jam code on some guns? Probly. But if you are smart and slow, then shutdown the Jtransponderand allow them to hit you , then it may be an elcheapo way to help save your ass.

we will know tomorrow if this has all been in vain or not

[Lucky225]

They don't sell 555s at ratshack any more?

[Solion]

sadly not , you can buy them online through their website. but not in most stores.

It has become an electronics store with parts as a sideline . FRYs however, mmmmm parts heaven

[Solion]

TEST RESULTS OF THE HOME MADE LIDAR JA_,TRANSPONDER



Well Cat4 was kind enough to put up with me and my mad science today in the not so wonderful weather, However we did get a break for abit, a respite from the rain to test 2 things...

First the offboard heads driven by a blinder unit. to be frank, given all that was said here I was not expecting much from this setup. Timings being as crucial as they are for a successful ja---transponder interferance. all I could do was hope. However..against the PLIII the blinder driven offboard heads punch through only happened at about 328 feet ( if I am wrong Cat4 will correct me) this is a significant step forward since the last test (since the last test was such an epic fail anything would be better) On this side of things I may adjust the power output to the leds, such low rates are just not getting them lit bright enough. But the viability of offboard heads seems plausible at least and worth looking into.

Now for the other side of things..... The home made Transponder . this is a square wave generator driving the FET unit used by the blinder test. that when fired by a elcheapo laser detector will transponderize a gun. my starting rate was 2 khz... and the result?

EPIC FAIL!!!... thats right, 2khz right to the leds = epic fail Like there wasn't even any jamming at all. max range punch through... However , Undaunted I had brought more than one frequency to drive the generator.. SO , I decided to go for broke. 90 KHZ it was the highest one I could drive for this test. So .. Shrug? why not ..

Aaannnddddd Drum roll please .... EPIC WIN!. punch through center mass at.. wait for it..

28 feet !!

Second run (just so I and Cat4 were not hallucinating) Headlight shot

128 feet!!

I went then and adjusted the led array to see if I could improve the headlight shot .. answer was ..... Feh 220 feet. I adjusted wrong ...

I then swapped in a cap for 50khz just to see what would happen and adjusted the led array back into place ... the last shot was 28 feet again , but I don't know if the was a CM or headlight, Cat4 can tell us here this evening.

This is the way I remember it. If Cat4 says different Ill default to him as I am a giddy mad scientist at the moment. As for jam codes. this was just against the PL3 so no jam codes for that gun. but given the epic fail that was my previous attempt, this is a major improvement.

Now to tune this bugger UP!

[The Chariot]

I wanted to be the first to say congratulations!

[wesley_willis]

very nice

[Solion]

I wanted to be the first to say congratulations!

Thanks , this has been a great bit of mad science fun and I am not done yet. with an offboard array there is no reason I cannot now build maker lamp arrays to fit my corner lights and even my headlights.

I will continue to expand the array bit by bit till we are rock solid. and I may pump the rates up to 1-4 MHZ at some point But 50 and 90 khz worked well. One step at a time as they say. Will know allot more when we shoot other guns at it. can't wait till the end of the month to see the overall numbers at the frozen toes event

we will need a "mad scientist " column for our test results

[speed-dreams]

very nice... now try to get a micro PIC or a RISC program it, find a Oscilloscope with a A/D system that collects data, and try to borrow the guns from somebody, and you'll have your own jammer

[Solion]

very nice... now try to get a micro PIC or a RISC program it, find a Oscilloscope with a A/D system that collects data, and try to borrow the guns from somebody, and you'll have your own jammer

HEH, well if I wanted a jammer that would not throw jam codes that would be a way to go. But most guns out there don't throw codes at all. this is a 40.00 build almost anyone with a soldering iron and a trip to ratshack could build (save for the vishay 890's from digikey)

It jams the PLIII. I wont consider this a complete success till we have done a few other guns. But as it is I am doing better than laser star with the PLIII,

The only guns I think I need to worry about is the laser Atlanta (of which I am told it will throw a jam code on headlights sometimes) and the Stalker.

The trafipatrol gun would be tough, But its in Europe only

I am going forward today and ordering more the the Vishay leds for the marker lights and the heads for the rear of the car.

At the end of the month there will be a full scale test across several guns I hope to be ready for it with a full loadout of Leds and various frequencies up to 4 mhz