Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: john@bovine.ati.com (John Higdon) Newsgroups: comp.dcom.telecom Subject: Re: Coin Station Fraud Using External Ground Message-ID: <6166@accuvax.nwu.edu> Date: 8 Apr 90 06:06:24 GMT Sender: news@accuvax.nwu.edu Reply-To: John Higdon Organization: TELECOM Digest Lines: 23 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 240, Message 5 of 8 Paul Colley writes: > I have a friend who can pulse-dial phone numbers by rapidly tapping > the hang-up button. > He claims, though I've never seen it, that this works at pay phones > without having to pay. I would like to see him do this at pay phones. For one thing, why bother? Use the TT pad; it works with or without coins being deposited in dial tone first phones. The other problem concerns how the hook switch is implemented in coin phones. To prevent (in the old days before "real" dial tone first) fraud in the manner you describe, they started using mercury switches instead of leaf contacts. The mercury cannot possibly follow the speed required to pulse dial numbers with the hook switch. BTW, I've seen for myself the mercury switch used inside pay phones. John Higdon | P. O. Box 7648 | +1 408 723 1395 john@bovine.ati.com | San Jose, CA 95150 | M o o !