Charlie Card carrying?

[elements.livejournal.com]

I got my Charlie Card LinkPass in the mail today (my employer has a pass discount program so I get my passes early in the mail). Hurray!

Except, the one thing that sucks is a big notice on the back of the card telling me I must not punch holes in it. There's no way to tell where the RFID chip resides, so no way to know if I'd be ruining the card by punching it. I know I can't be the only person who was expecting to hold onto this permanent pass by punching a hole and attaching it firmly to *something* - keeping track of the pass has been, apart from privacy issues, the only thing I've worried about at all w/r/t the Charlie Card. Now I'm at a loss - unless the MBTA figures out that they should be pre-punching them (I'd hoped they'd already be) and lets us all trade in our first cards. Doubt it, certainly any time soon.

So, anybody have ideas about secure sleeves with strings to attach these things? I don't know a ton about RFID so I'm not sure how much wrapping up they can take and still work well. I'm envisioning something along the lines of a luggage tag, but none of the ones I have at hand fit just right (a little too small). Has anyone else had the chance to try something out? Know of anyplace local selling the right size luggage tag holders? New cottage industry for our awesome local artisans? Anyone else with clever ideas?

ETA: Thanks for all the ideas, everyone. It looks like I'll be set for the immediate future, but I'm still curious about fun locally-made crafty alternatives for the longer term. (I think the vinyl ID holders aren't really secure or sturdy enough for the sort of use I'd put them to, strung on a string and stuffed daily into my backpack's hip pocket, and I may wait a little before daring to actually punch where folks tell me the RFID antenna isn't.)

Comments

[mrpet.livejournal.com]

The metal right through the center of the antenna would shift the resonant freq. of the antenna and reduce the range. Although seeing as how I do know how these things are designed there is a chance that it could make it better do to a mess up in the design. This also is the reason why holding your remote keyless entry fob up to your chin while pressing it will increase your range.

They are purposely detuned do to having too much power. The FCC demands a certain average power and it's easier to muck with a capacitor in the design that to lay it out again to change the antenna. You add parasitic capacitance into the antenna circuit and shift it back up.