Product: Phone Filter
Anti-telemarketer Phone Gateway   (+4, -1)  [vote for, against]
Pre-screens callers before your phone even rings

The Anti-Telemarketer Phone Gateway (ATPG) is a little interface device that plugs into any standard wall phone jack. You then plug your telephone into the other side of the ATPG. When the ATPG detects an incoming call, it doesn't make your phone ring -- instead, it immediately and silently "picks up" the line and delivers the following digitally recorded voice message:

"Hello. You have reached a line that does not accept telemarketing calls. If you are a telemarketer, you are instructed to place this number on your dont-call list, and hang up now. Anyone else may press (X) now to be connected"

(Substitute a number between 0 and 9 for X, depending on the setting of a 10-position hardware switch on the device)

At this point, a telemarker who was listening will have hung up (I believe they are required to by law--in any case, it would be dumb for them to continue on). A telemarketer who wasn't listening (because he wasn't ready for his autodialler's next number) will not know what to do next, and after a few seconds, the device will time out and hang up on him.

Your friends and other people you actually want to hear from, however, will press the given key on their touchpad. When the device hears the tone of the correct number being pressed, it then (and ONLY then) sends a 'start ringing now' signal on to your telephone. Your phone rings, you pick up the phone, and the ATPG then acts as a simple pass-through/wire until your conversation is finished.

This would eliminate all but the most perverse/ idiotic telemarketers. It would be only a slight inconvenience to your friends, because once they know the correct "secret pass digit" to press, they can press it immediately, without waiting for the entire message to play. The pass -digit then becomes like just another (unlisted) digit added to the end of your phone number.

Should the telemarketers ever catch on to your extra digit, simply set the switch to another digit to throw them off again.

I believe such a device could be made quite small and inexpensive (say, $19.95, and looking not much different from a standard phone cord with a few 'lumps' in it). All it would need is a microchip to play back the 8 seconds of announcement audio from ROM, and to listen for the keypad press. It could draw its power from the phone line itself.

Another option would be to incorporate this functionality as a feature of an answering machine--I believe modern all-digital answering machines already possess all the hardware needed to implement this; only the machine's firmware would need to be changed.
-- Jeremi, Apr 18 2002

(?) One phone company option http://www.qwest.co...354,702_1_8,00.html
Should have the desired effect [half, Apr 18 2002, last modified Oct 04 2004]

The TeleZapper http://www.telezapper.com/default.asp
"The TeleZapper uses the technology of telemarketers' automatic dialing equipment against them..." Of course, automated dialers are illegal in my state already, but this is an interesting piece o' tech, nonetheless. [bristolz, Apr 19 2002, last modified Oct 04 2004]

(?) Such a device apparently exists http:// www.theatersound.com/products.htm
cranfill's link as a link. [neelandan, Jun 01 2002]

(?) Such a device apparently exists http:// www.theatersound.com/products.htm
cranfill's link as a link. [neelandan, Oct 04 2004]

you want the tail to wag the dog?
-- thumbwax, Apr 18 2002


Pennsylvania has just created a state-wide "do not call" list, which all in-state telemarketers are required to use. Get your number on that one list, and no telemarketers can call you.

The intention is good, but it does nothing to stop out-of-state callers. There should be [insert country name here]-wide variants of this.

I think this is the ultimate solution to this problem... short of making telephone solicitation illegal (which I think is workable).

I've recently gotten into the habit of listening to telemarketers' opening statements, and then informing them that I'm not interested in doing business with them because I don't support companies that use telemarketing to promote their services.
-- waugsqueke, Apr 18 2002


Good luck generating the proper ringing voltage from your device if it is powered only by the line. On-hook voltage is significantly lower than ringing voltage, and so would have to be buffered out the wazoo and fed through a DC-DC converter. Off-hook voltage is even lower, and carries the added bonus of mucking up your audio path with power supply hum. Better just plug the darned thing into the wall.

If these devices became pervasive, computer auto-dialers would just be programmed to cycle through the ten possible digits until the connection went through. Computers are particularly well-suited to this type of drudgery.

No, a global ban on telemarketing would be much better. I already proclaim that I refuse to do business with companies that use telemarketers. The problem is that my local telephone company has joined the ranks of companies that use telemarketers. I don't have an alternative local phone company, so I can't tell mine to cancel my subscription. Thus my only options are to accept calls from marketdroids who can't pronounce my name, or to lobby for legislation prohibiting annoying calls.
-- BigBrother, Apr 18 2002


Good points, BigBrother. As for auto-dialers cycling through the digits, I think that is unlikely -- why waste time re-calling a number that is clearly not interested in hearing your message, to the extent that they bought a device just to block you? (Note that if the ATPG detects an incorrect tone, it immediately disconnects you) But if that did happen, we could change the device to use 2 or 3 digit pass-code sequences. Every additional digit in the code would increase the number of needed attempts by a factor of 10, making a brute force attack very expensive.

As for a global ban on telemarketing -- I'm all for that too, but it's not likely to happen. :^( And even if it was enacted, there would still be those who flaunted the law and called anyway. The benefit of a device like this is that you don't have to rely on the goodwill of telemarketers to voluntarily stop calling you.

waugsqueke, I like your method of dealing with telemarketers, but it doesn't really solve the problem I'd like to solve, in that you are still having to spend time answering the phone and talking to them. I'm trying to avoid that. : ^)

UnaBubba, exactly how is this a rant?
-- Jeremi, Apr 18 2002


blissmiss - such a thing is available for purchase in Connecticut? Can you give me more details? I might like to buy one.
-- Jeremi, Apr 18 2002


blissmiss - the legal solution is no solution at all, because it assumes that telemarketers are law-abiding (many aren't), and in the jurisdiction of the area the law affects (again, many aren't). You'll notice that waugs is still spending a lot of time "listening to marketer's opening arguments".

The benefit of this device is that you aren't forced to just wait for laws to be passed and telemarketers to follow them (ha!). You can take matters into your own hands, as it were, and solve the problem immediately and permanently.
-- Jeremi, Apr 18 2002


Something to consider: Won't all of the other phones in your house ring with the incoming call ? This "interceptor" device would have to interrupt the ringer voltage before it gets to any of your phones. It would have to be installed someplace further "upstream" than plugged in to the one phone. Unless you only have one phone.

I know there are devices that are plugged in-line with a phone/telecom device that prevents other devices from getting on the line when the protected device is already in use but I don't think this works to block the ring to the other devices initially.

Some bright telecom savvy person out there can probably verify/dispute this.
-- half, Apr 18 2002


Nice catch [half_crazy]. In my house I guess I could just turn the ringer off on all the un-filtered phones and still hear the one phone ring.
-- spartanica, Apr 18 2002


This idea is pretty much baked by our phone company. See link.
-- half, Apr 18 2002


Jeremi, as I had mentioned, the Pennsylvania laws were just recently passed, and the system is still in the process of being set up. Also, I had indicated that, being PA-centric, it does not stop calls coming in from other states, which is almost always the case for my calls. Hence my call for a national law, which I believe is being considered in the US. I seem to recall hearing something along those lines.

I believe it is safe to presume the companies are law-abiding. They need to be if they want to stay in business.

It makes far more sense to stop the problem from occuring at all, than to throw in a patch at the receiving end.
-- waugsqueke, Apr 19 2002


// I know there are devices that are plugged in-line with a phone/telecom device that prevents other devices from getting on the line when the protected device is already in use but I don't think this works to block the ring to the other devices initially. //

Most new homes are wired in a star configuration. This means that the local phone company brings one or more lines to a demarcation point, which is usually a small box mounted on an exterior wall of the home. Each telephone jack in the home has its own independent wires leading back to the box, where it gets connected to a phone line. All phones on a line are electrically in parallel with each other with one common upstream connection point (sometimes called the hub or star point).

Some older homes are wired in a daisy-chain configuration. This means that one jack is wired back to the demarcation point. Another jack is wired back to the first. A third jack is wired back to the second, and so on. The phones are still electrically in parallel, but now they share common wiring through the home and lack a central distribution point.

In either case, anything plugged into a jack is on a spur outside the path of other jacks. The only way to "disconnect" the other jacks is to short circuit the whole line.

However, an interruptor can be installed at the demarcation point. All in-house wiring except for a send/return loop is then connected downstream from the interruptor. When a device on this loop activates (let's say, an autodialer for an alarm system) it disconnects all downstream devices.

So the call screener could reside on this loop. It would provide line voltage, hook detection, and ringing voltage to the downstream devices. It would also provide ringing detection and auto-answer to the upstream line. Normally there would be no connection between the downstream and upstream paths. An incoming call would be answered by the device. Once the caller is authenticated, the screener rings the downstream side. If a downstream phone goes off hook, only then will the screener bridge the connection between upstream and downstream.

By the way, all the equipment to do the above exists today in PBX (Private Business Exchange) systems and telco central offices all around the world. You just need to scale it down a bit: one FXO to terminate the upstream side; one FXS to drive the downstream side; one very small (1x3) telephone switch matrix; and one automated voice response unit of simple design. Oh yeah, and the standard ten thousand percent price markup on all telecom equipment.
-- BigBrother, Apr 19 2002


If you can, call your phone company and get them to make your number ex-directory. We've had an ex-directory number in our flat for 3 years and have had precisely 2 unsolicited phonecalls, both of them looking for the previous occupant.
-- calum, Apr 19 2002


Such a device apparently exists, and is being brought to market by a company called Spectrum Research. See http://www.theatersound.com/products.htm

It's called "The Screen Machine", and BestBuys has them for sale on their web site (not in the stores).

I may try to get one; if I do, I'll post here as to how (well) it works..... - cran
-- cranfill, May 31 2002


Add a feature that automatically lets through approved callers based on their caller ID and I'm in for it.
-- andrewm, Jan 25 2003



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