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.
]]>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.
]]>Let us know how it works out
Regarding your other post... I'll reply in that thread...
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