Proxmark3 community

fazer

Contributor

Registered: 2019-03-02

Posts: 156

LF antenne

Good evening, I am coming to you because I bought an LF antenna as well as 125khz t55 rewritable badges at Lab401 this week. I installed antenna on my proxmark3 rdv4 with a read badge, impossible to read the badge I tried with another badge idem it does not detect the badge, I reassembled my dual pocket antenna I detected the badge lf em 4x50 on the other hand the badge t55xx impossible I do not understand why I tried more position, raised the badge nothing. Do you have any idea of the problem.
Thank you good night.

[usb] pm3 --> hw tune
[=] ---------- Reminder ------------------------
[=] `hw tune` doesn't actively tune your antennas,
[=] it's only informative.
[=] Measuring antenna characteristics, please wait...
?   9
[=] ---------- LF Antenna ----------
[+] LF antenna: 66,31 V - 125,00 kHz
[+] LF antenna: 36,53 V - 134,83 kHz
[+] LF optimal: 69,19 V - 126,32 kHz
[+] Approx. Q factor (*): 12,0 by frequency bandwidth measurement
[+] Approx. Q factor (*): 12,1 by peak voltage measurement
[+] LF antenna is OK
[=] ---------- HF Antenna ----------
[+] HF antenna: 46,62 V - 13.56 MHz
[+] Approx. Q factor (*): 8,1 by peak voltage measurement
[+] HF antenna is OK

(*) Q factor must be measured without tag on the antenna

[+] Displaying LF tuning graph. Divisor 88 (blue) is 134,83 kHz, 95 (red) is 125,00 kHz.

Last edited by fazer (2021-05-08 18:21:49)

iceman

Administrator

Registered: 2013-04-25

Posts: 9,538

Website

Re: LF antenne

Have you set your Q switch to low (7)  ?

fazer

Contributor

Registered: 2019-03-02

Posts: 156

Re: LF antenne

Good evening Iceman, thank you for this quick answer, no I have not set Q swich to low (7), I am trying & I will keep you posted thank you very much.
Good night.
Good evening Iceman, where can I find the documentation to make this adjustment, thank you.

Last edited by fazer (2021-05-08 19:35:15)

iceman

Administrator

Registered: 2013-04-25

Posts: 9,538

Website

Re: LF antenne

if you flip over your rdv4 dual antenna,  you should see two switches.

fazer

Contributor

Registered: 2019-03-02

Posts: 156

Re: LF antenne

Hello Iceman, thank you I do not understand too much but I will look, I bought this LF antenna to have more precision on a pcf badge 7935aa (very sensitive),
Thank you good sunday

fazer

Contributor

Registered: 2019-03-02

Posts: 156

Re: LF antenne

Re Iceman, could you check .
thank you

[usb] pm3 --> hw status
[#] Memory
[#]   BigBuf_size.............40520
[#]   Available memory........40520
[#] Tracing
[#]   tracing ................1
[#]   traceLen ...............0
[#]   dma8 memory.............-2113648
[#]   dma16 memory............-2113648
[#]   toSend memory...........-2113648
[#] Current FPGA image
[#]   mode.................... LF image built for 2s30vq100 on 2020-07-08 at 23: 8: 7
[#] Flash memory
[#]   Baudrate................24 MHz
[#]   Init....................OK
[#]   Memory size.............2 mbits / 256 kb
[#]   Unique ID...............0xD567A882A7A17425
[#] Smart card module (ISO 7816)
[#]   version.................v3.11
[#] LF Sampling config
[#]   [q] divisor.............95 ( 125.00 kHz )
[#]   [b] bits per sample.....8
[#]   [d] decimation..........1
[#]   [a] averaging...........No
[#]   [t] trigger threshold...0
[#]   [s] samples to skip.....0 
[#] LF Sampling Stack
[#]   Max stack usage.........4096 / 8480 bytes
[#] LF T55XX config
[#]            [r]               [a]   [b]   [c]   [d]   [e]   [f]   [g]
[#]            mode            |start|write|write|write| read|write|write
[#]                            | gap | gap |  0  |  1  | gap |  2  |  3
[#] ---------------------------+-----+-----+-----+-----+-----+-----+------
[#] fixed bit length (default) |  29 |  17 |  15 |  47 |  15 | N/A | N/A | 
[#]     long leading reference |  29 |  17 |  18 |  50 |  15 | N/A | N/A | 
[#]               leading zero |  29 |  17 |  18 |  40 |  15 | N/A | N/A | 
[#]    1 of 4 coding reference |  29 |  17 |  15 |  31 |  15 |  47 |  63 | 
[#] 
[#] HF 14a config
[#]   [a] Anticol override....std    : follow standard 
[#]   [b] BCC override........std    : follow standard
[#]   [2] CL2 override........std    : follow standard
[#]   [3] CL3 override........std    : follow standard
[#]   [r] RATS override.......std    : follow standard 
[#] Transfer Speed
[#]   Sending packets to client...
[#]   Time elapsed............500ms
[#]   Bytes transferred.......285184
[#]   Transfer Speed PM3 -> Client = 570368 bytes/s
[#] Various
[#]   Max stack usage.........4096 / 8480 bytes
[#]   DBGLEVEL................1 ( ERROR )
[#]   ToSendMax...............-1
[#]   ToSend BUFFERSIZE.......2308
[#]   Slow clock..............30699 Hz
[#] Installed StandAlone Mode
[#]   LF skeleton mode -  aka Skeleton (iceman)
[#] Flash memory dictionary loaded
[#]   Mifare..................1094 keys
[#]   T55x7...................116 keys
[#]   iClass..................9 key
code.

I installed the LF antenna, I can not read a tag, I watched the video at lab401 that you posted but it is dated & does not speak of the rdv4, thank you again.

Re, I am a young retiree, I have a lot more time now, I will take the time to read the doc to try to understand your answer (Have you set your Q switch to low (7)?). Thank you again good Sunday.

Last edited by fazer (2021-05-09 11:34:18)

fazer

Contributor

Registered: 2019-03-02

Posts: 156

Re: LF antenne

Hello again Iceman, well I found behind the antenna there is a switch 125/134 & 14/7 thank you again for your help.
Good late afternoon

[usb] pm3 --> lf t55xx dump
[+] Reading Page 0:
[+] blk | hex data | binary                           | ascii
[+] ----+----------+----------------------------------+-------
[+]  00 | 000880E8 | 00000000000010001000000011101000 | ....
[+]  01 | 00000000 | 00000000000000000000000000000000 | ....
[+]  02 | 00000000 | 00000000000000000000000000000000 | ....
[+]  03 | 00000000 | 00000000000000000000000000000000 | ....
[+]  04 | 00000000 | 00000000000000000000000000000000 | ....
[+]  05 | 00000000 | 00000000000000000000000000000000 | ....
[+]  06 | 00000000 | 00000000000000000000000000000000 | ....
[+]  07 | 00000000 | 00000000000000000000000000000000 | ....
[+] Reading Page 1:
[+] blk | hex data | binary                           | ascii
[+] ----+----------+----------------------------------+-------
[+]  00 | 000880E8 | 00000000000010001000000011101000 | ....
[+]  01 | E0150A91 | 11100000000101010000101010010001 | ....
[+]  02 | FE03A4CB | 11111110000000111010010011001011 | ....
[+]  03 | 00000000 | 00000000000000000000000000000000 | ....
[+] saved to json file lf-t55xx-dump.json
[+] saved 12 blocks to text file lf-t55xx-dump.eml
[+] saved 48 bytes to binary file lf-t55xx-dump.bin
code.

Last edited by fazer (2021-05-09 16:35:41)