• Registered: 2010-01-29
  • Posts: 4

Topic: HF atenna is unusable

my pm3 is done by myself.My LF atenna is working ok while my HF is awayls not.When using tune command,HF atenna only has a voltage of 0.10V or 0.06V.SO I change my HF atenna several times,but it doesn't work, now I suppose my HF hardware maybe has some problems,but I couldn't find it .My version is from 20090905 zip.
Need your opinions please! Many THANKS!

  • Cex
  • New member
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  • Registered: 2009-12-14
  • Posts: 7

Re: HF atenna is unusable

Your HF voltage is too low.
It looks like your HF path is open or coil drivers are not working.

I would check solder joints for hirose conector, change hirose cable, check solder joints on HF tuning capacitor and 244 drivers.
You could also check solder joint on RX path components.

If you build the proxmark yourself, check that you mounted the component on proper locations (check that non-mounted components are in proper locations, you can use one of the hi-res photos in the files section) and did not swap values.

If you have access to an oscilloscope you can check voltage at coil, so you can check if the problem is in the coil drivers or in the RX path. If not you can use some turn of enamel wire soldered to a LED diode and check if it lights up when placed nead the antenna. If it lights up, the coils drivers are working.

Hope this helps.

Regards,
Cex.

  • Registered: 2010-01-29
  • Posts: 4

Re: HF atenna is unusable

Cex，thanks for your answer.

I have checked solder joints and RX path componnents,and they were ok.Then I used oscilloscope to check the voltage at coil,it was about 3.2V while the response for tune command was still "0.10V@13.56 MHz,your HF antenna is unusable" .
So I put a a 15693-tag in the centre of the coil and tried to read it,however it did worked sometimes as follow,but most of time it couldn't read it right.I thought my HF path still had some problems with my componnents,but it was so strange,and I just need do more work on it.

> hi15read
> hisamples
> hi15demod
SOF at 10, correlation 0
EOF at 414
error, uneven octet! (discard extra bits!)
   mask=02
12 octets
#  0: 00
#  1: 00
#  2: 1d
#  3: 1e
#  4: d0
#  5: 18
#  6: 00
#  7: 00
#  8: 07
#  9: e0
# 10: 80
# 11: a0
CRC=b090

  • Registered: 2010-01-29
  • Posts: 4

Re: HF atenna is unusable

Hi，all guys.
My problem is still unsloved.when using tune command,the response is HF antenna is unusable(only 0.10V) while LF antenna is 20V more or less.Here is my pm3 imformation.
My C35 is 100pF,and miccontoller is at91sam7s256.
I used H-JTAG(software)for the first time via the jtag to load the prox_image.bin in the ProxBin-JW file downloaded from the 'www.proxmark.com'.Then I load the bootrom.s19  fpgaimage.s19 osimage.s19 file from the 'pm3-20090905-r216' in the '2009.09.05.ProxSpace'.The prox.exe is also from winsrc file in the 'pm3-20090905-r216'.

Hope your help,THANKS!

  • Registered: 2008-08-19
  • Posts: 291

Re: HF atenna is unusable

What's your HF antenna like, dimensions, turns etc?

  • Registered: 2010-01-29
  • Posts: 4

Re: HF atenna is unusable

I have tried many kinds of HF antenna.
rectangle 76mm*45mm  4 turns,PCB board antanna, line width 40 mile;
round diametre 65mm~70mm 3 turns or 4 turns, aluminum wire(D 20 mile) or thin enamelled wire;
And reponse is always 0.10V but in actually it has a voltage of 4V in coil using an oscilloscope.Sometimes it even could read 15693-tag UID right.