ProxMark3 low voltage on lf and hf antenna ( < 23 mV ) No implant read

[ldzuira]

Hello guys !

I got implanted with a NExT about 3 weeks ago, swelling is not noticeable.
I just received my Proxmark3, and followed the tutorial from Amal, everything works correctly.

I started by cloning a HID card to a blank 125khz card and it worked perfectly.
Now i wanted to detect the 125khz chip of my NExT to clone this specific card to the chip.

I used the lf tune to get try and position myself correctly and saw that my max voltage was 10 mV below the average ( got max 24 mV )

I first isolated the Proxmark from my desk, then tried all my usb ports, checked with another cable and the voltage is still low.

I used the implant in epoxy to see if it shines and it does but the drop in voltage is unnoticeable ( < 0.100 mV )

I haven’t been able to scan my NExT 125khz chip ( only got 1 false positive with an Indala card )

I tried to scan my Spark2 and my 13.56MHZ chip on my NExT and also got no read from the ProxMark

I know for a fact that these 2 chip works since i can scan them very easily and at a good distance with both my phone and my keyboard wedge reader and use them pretty much daily.

It’s my first time tinkering with the Proxmark3 and 125khz chips, so i’m by no mean an expert and was wondering if maybe there is something wrong with my Proxmark or my NExT ?

[amal]

It can be tricky positioning the proxmark3 over a NExT, especially when it’s implanted and hard to pin down exactly where it is under the skin.

First off, if you’ve not found this gem, I would make use of the delay command;

How to add a delay to Proxmark3 commands for implantees

Having an implant in your body and trying to use the Proxmark3 can be a tricky balancing act of trying to hold the Proxmark3 antenna just so over your implant and then trying to hit Enter to initiate the command. But, there is a way to solve this by using the msleep command along with command chaining to add a delay between pressing enter and the command you want to execute against your implant is actually run. For example, to perform an lf search with a 3 second delay before actually performing…

Now you have a fighting chance to properly position the LF antenna coil directly over the NExT.

When it comes to HF, it’s important to note that the actual HF antenna coil is on the bottom PCB, not the middle PCB which is what you see looking down at the top. If you look closely at the bottom PCB you can see the traces of the HF antenna coil running on the top side of the bottom PCB… basically sitting between the bottom PCB and the middle PCB. Because of this, you get much better reads of x-series implants if you actually just place the proxmark3 down on your NExT so the bottom PCB is resting with the antenna traces running perpendicular across your NExT.

Finally, the voltage levels do vary a considerable amount with every proxmark3. If your hw tune indicates both antennas are ok, then they should work just fine with the NExT when ideally positioned.

[XC-108]

@amal

you get much better reads of x-series implants if you actually just place the proxmark3 down on your NExT so the bottom PCB is resting with the antenna traces running perpendicular across your NExT

It took many tries to find the right spot. And the comment about being Perpendicular was key for me. Thank you for this. I employed my teenager to hold the Proxmark in the right place after I got a positive read. LOL. Now I have a successful clone, it looks like!