Finally got my RFID cloner working after 3 tries

Cracked it open at the Denver public library parking lot yesterday. Turns out I was using the wrong antenna coil size this whole time. Anybody else had to swap coils to get their reader to actually pick up signals?

3 comments

3 Comments

kimfisher5d agoOG Member

Wait, hold on. You said "capacitor matching?" That's wild to me. I've been messing with these things for a few years and I always just swapped coils until it worked. Never even touched the caps. I had no idea they had to match up like that. So you're telling me I could have just matched the capacitors instead of ordering five different coil sizes? That would have saved me like two weeks of waiting for shipping. I always thought the coil was the only thing that mattered for tuning the frequency. Now I feel like I've been doing this all wrong.

leo_black765d ago

Wait, you had to swap coil sizes just to get a read? In my experience that usually means your original coil was just way too far off frequency wise. I've messed with those 125kHz readers a bunch and the standard antenna coil is like 1.4mH or so, but if you're trying to read something like a HID Prox card the sizing has to be pretty close. The bigger issue is usually the capacitor matching though, not just the coil itself. You might want to check if your capacitor values are actually lining up with what you swapped to, otherwise you could still be missing reads even with the new coil.

corap215d ago

Oh man, capacitor matching. That's the kind of stuff you learn after you've already thrown money at the wrong parts, right? I spent like two weeks convinced my reader was haunted because I swapped coils three times and still got nothing. Turns out I had a cap that was way off spec, like a drunk guess at the value. Now I just keep a little stash of random caps for when I inevitably mess something up.