Proxmark3 community

terrizzi

Member

Registered: 2010-03-05

Posts: 4

Ordered 125K kits from qKits

I didnt really feel like running tune 47 times to get a perfect antenna. I ordered two AN0201 and AN0301 types, ill test them out and let you guys know.

http://store.qkits.com/moreinfo.cfm/AN0201

http://store.qkits.com/moreinfo.cfm/AN0301

d18c7db

Contributor

Registered: 2008-08-19

Posts: 292

Re: Ordered 125K kits from qKits

I have a feeling you don't understand how antennas work, it is a tuned LC circuit where L stands for the coil and C is the capacitor already fitted to the board. Buying some random coil off the internet that does not specify the inductance of the coil but just says it's for "125Khz RFID" is no guarantee of success at all. Still at $3 it's no big loss either so worth a try

Let us know how it works out

Regarding your other post... I'll reply in that thread...

terrizzi

Member

Registered: 2010-03-05

Posts: 4

Re: Ordered 125K kits from qKits

well your right.

i just receieved a board from proxmark3. Im not sure what capacitor is attached to the board.

There just isnt much with reguards to how to make a good 125k antenna for the proxmark.

ntk

Contributor

Registered: 2015-05-24

Posts: 701

Re: Ordered 125K kits from qKits

I have made similar mistake like Terrizzi. and hope someone here can give me advice what is going wrong

Very hard to make a LF antenna.

From Farnell the thinest wire I can buy is 0.6mm bell wire, Multi-Strand.
My antenna diameter is 2,5cm, I rolled 100 turns, then reduced number of turns down to 90, 80, 70, 50, but the best voltage I could get some time is 4.28V, and best freq is 244 kHZ. Mostly 'HW tune' shows me optimal 0.00V @ 12000.00 kHz, as if there is no connection. bad Hirose conector? I think I test by solder serial a mini motor to the circuit. Each time I ran 'HW tune', the motor rotates, so connection was always there, but why only sometimes, (1 or 2 out of of 10 or less)  'HW tune' shows different value then 12000 kHz. Is it because wire diameter isn't correct?

I also bought the coil from ebay
http://www.ebay.co.uk/itm/RFID-Antenna-coils-125Khz-x-5-RF-Radio-Frequency-/151821810577?hash=item235948fb91.
Also with these coils most of the time tuning shows 12000.00 kHz, (as if no antenna connected) but test with the mini motor show each 'HW tune' makes the motor running!

although it is advertised as 125 kHz coil, sometimes it shows a resonance frequency at 413kHz; not 125 kHz, and the voltage is only 0.28V. I also reduced here the turn by 5x, 10. I repeated at least 5 times but I did't see the value change from 12000 KHz, or 400 kHz. I wasted already 3 coils, but I did not come anywhere consistently near 125 kHz, I did also test with a mini motor in serial and every time command 'HW tune' did turn motor.  What did I do wrong?

How can I fix it to use these coils with proxmark3? size of the coil 1cmx4cmx0.5cm. Enamel wire very thin but I don't know how thin. Seller gives me only coil size infos.

Last edited by ntk (2015-09-28 10:56:15)

ntk

Contributor

Registered: 2015-05-24

Posts: 701

Re: Ordered 125K kits from qKits

found this on Amazone. many type of AWG30 wire, could the experienced users tell me which one is suitable?

AWG magnet wire