Proxmark LF Antennas

spoiler: this didnt actually work.

It’s basically bolted in right,? maybe replace the existing fasteners with longer ones, add some washers or nuts as spacers to isolate electrically from the other LF connections, and connect as usual? As long as they are conductive it (shouldn’t) cause any loss. When mine finally gets here I’ll be doing that.

Edit: I just tried some M2 screws I had on hand, they don’t fit and the nuts might be soldered in? My callipers say they are 1.5mm, maybe my local hardware store has some.

Edit2: so I peeled off the kapton tape from the back of the HF screw holes and just bolted it in on the back. seems to be working fine. might be too little clearance for the LF antenna to go on top though.

[usb] pm3 --> hw tune

[=] Measuring antenna characteristics, please wait…

[=] You can cancel this operation by pressing the pm3 button

[!] LF antenna is UNUSABLE

[+] HF antenna: 49.29 V - 13.56 MHz
[+] HF antenna is OK

[-] Not showing LF tuning graph since all values is zero.

Capture

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Would be interested to know how you get on.

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image

It looks great and works a charm. I updated the data on my LF part of the next yesterday evening.

Thank you so much. This is fantastic work!

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If you cut the LF board section off completely and trimmed a bit of the HF top plate (I’m pretty sure the coil underneath does not rely on it), you could fit it on top of the new board. You might have to install the LF board from the back side of the Proxmark, but it could just barely fit with under 1mm hitting the LF coil’s cover.

Glad to hear :smiley:

I can’t recommend trying tp attach a HF antenna alongside this. I’m hoping to make a ProxDF antenna soon and will update the community here as things progress.

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Are there HF use cases that this would work for that an Android phone couldn’t do? Currently, I haven’t had any issues programming the HF side of my NEXT chip with my Samsung Note 8, so not sure I’d need a HF antenna - I’ve mainly ordered this for programming the LF side.

Hello everyone! I got my antenna this afternoon and gave it a go. It reads great from a pretty good distance, 1-2 cm or so with no problem. But when I try to do a hw tune, I get a message that the LF antenna is unusable. I have already tried to re-mount the antenna, use a different cable, and restart the program multiple times but always get the same message with the exact same voltage values each time. Any ideas? I don’t want to attempt a write until I have the antenna properly tuned.

wow… 3388211.20v at 134kHz?! feels like something else is off… is your CLI client matching your firmware here?

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This is common if you’ve got mismatched client and firmware versions. Please use the latest release or latest Git pull and compile from the Rfid Research Group repository, remember to flash the latest bootloader and full image before doing anything.

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Excellent work @TomHarkness. The new LF coil antenna words perfectly. I was able to read my new NeXT implant while still sealed in the poly bag, sterile packaging, and stainless steel insertion needle. Once implanted, I jumped the gun and used my phone to successfully read the HF (NTAG216) chip. Once home, I installed and tuned the new coil antenna on my Proxmark3 and did several LF searches / antenna re-positions until I found the optimal read location (solid waveform and detection of the T5577). One “hid clone” command later and my implant was ready to open my office door. Thanks Amal and DT for an excellent product and Tom for the kick ass antenna.

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Has anyone attempted to connect this to other Proxmark3’s? I ended up ordering the wrong device, I think it’s actually a Proxmark3 Easy. I removed the stock LF antenna, and using low-quality jumpers I wired up the three terminals on the antenna sold here and got these numbers:

Measuring antenna characteristics, please wait.........
# LF antenna: 10.31 V @   125.00 kHz
# LF antenna: 10.86 V @   134.00 kHz          
# LF optimal: 21.17 V @   196.72 kHz
# HF antenna: 28.86 V @    13.56 MHz
Displaying LF tuning graph. Divisor 89 is 134khz, 95 is 125khz.

The stock LF antenna gives me:

Measuring antenna characteristics, please wait.........
# LF antenna: 43.04 V @   125.00 kHz
# LF antenna: 38.36 V @   134.00 kHz
# LF optimal: 47.57 V @   127.66 kHz
# HF antenna: 28.86 V @    13.56 MHz
Displaying LF tuning graph. Divisor 89 is 134khz, 95 is 125khz.

Are the first set of numbers acceptable? I imagine they would improve if I used better quality jumpers, but I just wanted to do a quick test to see if I could use the antenna or not.

it’s pretty terrible… you might (might) get results if you can remove the tuning caps from your proxmark3 board… the rdv4 modularizes the antennas by putting tuning caps on the antenna module not the main board… but of course you could just ruin your pm3 by doing this… soo… careful?

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Well, I just tried programming my NExT using the stock antenna on my PM3 Easy while it’s still in it’s applicator which is still in the pouch labelled “do not open this much until…” and it seemed to work, so I took the whole pouch and was able to open a door in my building with it, so I guess I’m ready to have it implanted.

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How the hell??? I can BARELY read my implanted NExT with stock PM3 Easy antenna after hundred of tries pushing my hand hard into antenna, tho it reads perfectly using all my door readers. I even used blue cloner to program the lf-part finally because it was impossible pm3 (I know about blue cloner perils and I know how to unpassword T5577 after it).

There was definitely a sweet spot on the circular antenna of the PM3E that I determined using the LF XFD. Since I’ve purchased the LF antenna from DT, I’ll probably still buy the PM3 RDV4.01 for changing the programming as I’m sure it won’t work once it’s under my skin. I was afraid that I had bricked it at first, because after I issued the lf hid clone , it became harder to lf search for, but would appear. I then went and tried it out on one of my building’s HID readers and the door opened. I’ve got an appointment on Monday to have it installed. I purchased two NExT chips, I haven’t decided if I’ll have them both done on the same day or if I want to have one non-injured hand available.

Do you have the LF XFD @koteeq? If so, use it to determine the sweet spot to couple with the stock PM3E antenna.

Yep, I had that field detector included into my NExT kit but I even forgot to try it with pm3.

I’m sure it will work much better when implanted for you because your skin is nothing compared to metal syringe that blocks signal + sterile pouch + plastic pouch + long distance.

Just admit that your stock antenna is magical.
I’m really happy for you :slight_smile:

Good luck with implanting your NExT!