DIY LF antenna for Proxmark 3 Easy

That’s kind of why I went straight for that one: I had a feeling it’s one of those things you end up buying anyway in the end because it’s just plain better, and you regret blown money on the inferior version of.

Yea I bought from piswords, apparently I got bundle 1

So I can’t find any other information on what the various light configurations mean, I can tap or hold the button and the light changes to various colors or posistions

Super lost on it if I’m being honest even though I managed to clone my prox work badge to a generic 125khz card

This may help scroll to the bottom there are video links

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Ok well I finally got my pm3 installed thanks to some help from darthdomo

Now to start looking at making an antenna

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Just a thought… before I commit to a build

Could I buy the prox lf antenna for the rdv4 and gut the antenna from it?

Might be easier / cheaper than building from scratch

Apparently the main issue is that the rdv4 has all of the tuning circuitry on the antenna boards, allowing for very weird designs, whereas previous versions of the Proxmark 3 have on board fixed tuning circuitry that means that rdv4 antennas aren’t compatible.

See here for a better explanation:

Here is someone else who tried what you’re proposing without modification:

(my understanding of antenna design would suggest that if you could figure out / measure the value of the tuning caps on your easy, you might be able to counteract them with other passives, but working out what works best could be very difficult) - you can see a test board by the designer of the ProxLF with multiple values for tuning here:

Hope this helped!

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I finally got the supplies in so I’m trying this out now. Unfortunately my PM3 Easy doesn’t even detect the antenna. I honestly have no idea what I’m doing so I’m just following what you guys did.

This is what I have:

When I run “hw tune” I get

[=] ---------- LF Antenna ----------
[+] LF optimal: 1832072.03 V -   0.00 kHz
[+] LF antenna is OK
[=] ---------- HF Antenna ----------
[+] HF antenna: 32.47 V - 13.56 MHz
[+] HF antenna is OK

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

Is there something obvious that I’m doing wrong? I used superglue to hold the wire in certain spots but I tried to wipe up the excess. I also have about 20cm of extra wire on one end in case I needed more windings. The ferrite rod is cut to a little less than 3.5cm (since 2.5cm was too short for @Compgeek)

Have you checked it for continuity? Could have a break in there maybe

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Sorry if this is obvious……. you’ve removed the enamel of the wire where it connects to your Proxmark PCB?

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Uhhh…I’ll be back for an update shortly…

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Hehe, thats the noob catch lol.

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Is this good?

[=] ---------- LF Antenna ----------
[+] LF antenna: 10.92 V - 125.00 kHz
[+] LF antenna: 11.34 V - 134.83 kHz
[+] LF optimal: 32.78 V - 218.18 kHz
[+] LF antenna is OK
[=] ---------- HF Antenna ----------
[+] HF antenna: 32.54 V - 13.56 MHz
[+] HF antenna is OK

[+] Displaying LF tuning graph. Divisor 88 is 134.83 kHz, 95 is 125.00 kHz.

Edit: Nevermind. I see that the “LF optimal” is what I should be looking at so 218.18kHz isn’t good.

Well at least it’s working now :laughing: Yeah it’s obviously high in frequency so you need more turns.

Dang it! I ran out of space and I’m still not close to 125kHz

[=] ---------- LF Antenna ----------
[+] LF antenna: 13.35 V - 125.00 kHz
[+] LF antenna: 15.14 V - 134.83 kHz
[+] LF optimal: 40.67 V - 171.43 kHz
[+] LF antenna is OK

I have enough ferrite and wire to try another day.

You can layer it :wink:

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Glad I let @Nimus go first lol

Absolutely would have forgotten about that

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Would it still work fine with the extra wire soldiered on? I accidentally cut the wire too short so I’d have to add some more. Sorry for all the noob questions.

Are you using an LCR meter?

If not does that mean I can skip it on my parts list?

Yep, just make sure the joint is tidy, I mean of course would be better not to have solder joints but it will work fine.

Well, it’s not pretty but

Thanks for he help everyone! I’ll try to stop embarrassing myself with these questions…

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