Proxmark3 community

Tooms

Member

Registered: 2016-04-26

Posts: 4

high volts on the LF

Hi

i am reading the wiki doc and it is saying: https://github.com/Proxmark/proxmark3/wiki/antennas
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>Low frequency antenna
>
>Low frequency coils should be connected between TP2 and TP5 either on the Hirose connector or soldered direct to the test points. >A standard 125kHz coil is made of around a hundred turns of thin enamel wire (preferably 0.1 mm).
>
>The tune command should return a value of over 20 Volts for a properly tuned antenna but it should not exceed 45 Volts; if lower, >interaction with LF tags may be incorrect.
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then i test my proxmark 3r2 from elechouse to see what it is:
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>proxmark3> hw tune
>Measuring antenna characteristics, please wait...#db# DownloadFPGA(len: 42096)                 
>......#db# DownloadFPGA(len: 42096)                 
>.         
># LF antenna: 46.20 V @   125.00 kHz         
># LF antenna: 21.04 V @   134.00 kHz         
># LF optimal: 46.20 V @   125.00 kHz         
># HF antenna: 22.47 V @    13.56 MHz         
>Displaying LF tuning graph. Divisor 89 is 134khz, 95 is 125khz.
>proxmark3>
>-------------------------------------------------------------------------------------

So the doc says max 45 volt and the hw tune return it as 46.2v,  is that a bad thing and if yes then how do i correct it ?

Thanks

Tooms

marshmellow

Contributor

From: US

Registered: 2013-06-10

Posts: 2,302

Re: high volts on the LF

The tune command was tuned to be more accurate a year or so ago, which changed this slightly.  Your setup is fine.

Tooms

Member

Registered: 2016-04-26

Posts: 4

Re: high volts on the LF

Thanks for the reply, was just concern if it will damage the device but from what you say it is fine.

Thanks

Tooms