NExT & Off The Shelf Car Starting Module, but still a work in progress

Okay, so. Last week, I got my first implants Spark2 + NExT.

Then I ordered a Proxmark3, which arrived yesterday. Was able to get it going thanks to the very detailed instructions (thanks Amal). Used it to clone the backup key card for my Digital Guard Dawg ( pushbutton start system. The system uses active powered keys, but has a backup key card like so:

Which was easily cloned with the Proxmark3.

I had to move the antenna from under the dash, because while the backup key card was easily read through the fiberglass, I didn’t suspect the NExT would be. Antenna is the black thing in my hand here:

I can start the car successfully, but the antenna will HAVE to be mounted away from the aluminum dash, but even when held at a distance, it takes some fiddling to get it to start.

Any tips on boosting strength, or sourcing/building an antenna better suited to the implant?

Either way, I’m pretty stoked that this worked (sort of) with my already installed system!


first I would ask them if you can buy a replacement antenna to see if you can get a spare… then measure the inductance of that spare antenna… then you can go about re-creating it in a new shape (with the same inductance) that may work better for you… for example, a cylindrical coil shape?


Perfect, I’ve reached out to them, I’ll keep everyone posted when I have more info. Having an off-the-shelf system that requires minimal modification would be a great tool-kit add!


Update: for $50 they sent me a replacement antenna. Kinda steep for something I’m not eventually going to use, but now I’m committed.

For much less, I also picked up an LCR meter and some 28 AWG enameled magnet wire.

Tested the new antenna in the system to verify it’s function. Same okay-ish result. Measured the inductance of the antenna:

Then it was time to play. I wound some of the magnet wire around a screwdriver shaft, taped it, sanded the ends, pulled it off and fell WAY short:

Next up was the same process with a marker. 10x improvement:

I was also able to use a special method to inspect the inside of the antenna:

A magnet was able to tell me the black core is ferrous.

Any insight into:

  1. What does the core do?
  2. Did my inductance increase because my diameter increased, or because more wire was used to get the larger diameter with the same antenna length?

I can see this turning (zing) into a fun hobby!

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The core increases the inductance.

For the second question should look up the formula :smiley:

I used this ( ferrite rod to wind my own coil to 1.33 mH. Used some wire from old electromagnet :slight_smile:

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Thanks @Tehol,

I’ve played around with making a few more antennas, using new wire, and reusing the wire from that antenna. I think I have a good antenna now (the one that came with my DG Access Kit actually worked pretty well too) - I’ve built several - the best tool for testing is the small LF blinky that came with the NExT. The brighter the flash, the stronger the signal.

Now I just need to create a mount for it away from all of the metal on the car - the dash, frame, center console… All metal.

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