Newer cards may have a charge-pump built in, that is often activated by a logic level on pin six. However, the PTT did something to the booths, that caused all clones to stop working. As a matter of fact, even real cards seem to have problems now. A real card attached to an adapter doesn't work as well. I expect this to be some hardware trick.
Any input is appreciated.
KPN being, well, 'Dutch', will go no further than stopping the criminal use of chipcards. It was published how to route the wires to beat the wire detector in Klaphek , the 'Dutch' hacker magazine and KPN promptly abandoned the devices. In otherwords, long wires will distort the analogue characteristics of the signals resulting in rejection of the card. Very short wires will work and so will compensation techniques for somewhat longer wires. Analogue technology is very complicated and therefore beyond the scope of this text.