AT&T 1985 phone weird warning "This telephone set is NOT FOR RESIDENTIAL USE"

[putzina]

I'm new to this forum, but perhaps someone with more technical knowledge than I thought I had already could shed some light on something very strange. I bought a new old stock black AT&T rotary phone from someone on eBay and have it plugged into my VOIP line. It has great sound quality and rings beautifully on incoming calls. Of course, I can't yet use the rotary dial to call out until I buy a pulse-to-tone converter, because my ATA only supports tone dialling, but I don't mind because I mostly call US numbers via Google voice and so don't need to dial from the phone itself.

However, the phone came with a weird warning card that says:

"CAUTION! THE FOLLOWING SAFETY INFORMATION IS IMPORTANT TO YOU.
This telephone set is NOT FOR RESIDENTIAL USE. It is sold for BUSINESS APPLICATIONS ONLY. Use in a residential environment could result in an electrical short circuit when the telephone wiring is set up to provide other applications e.g. appliance control, power transformers lighting telephones, etc. The AC power used in these applications may create a safety hazard since lifting the handset from the telephone base places a direct short circuit across the telephone wiring."

That last part "direct short circuit across the telephone wiring" is especially scary. Would it be safe to connect this phone to a normal PSTN phone line? Is this bizarre warning card from 1985 relevant to 2010? How is this rotary phone any different from a rotary phone "intended for residential" use?

What gives with this warning? Thanks.   

[Jim Stettler]

I guess you need to start a business.

It sounds like you might have a second pair of wires in the (phone's) jack.

The warning is probably  If your house was wired with CEBUS? (cat 5 and 2 coax at all locations),  cabling  then some of the twisted pair may get used for something else.

If you use a 2 conductor mod line cord, this should keep the phone from shorting out any of the other twisted pairs.

Another way is to make sure the wall jack only has two wires hooked up, or do it in the phone.
Jim S.

[putzina]

Thanks. I think the cord I have it plugged into only has two wires in it, not four, so I'm probably OK. Still, I wasn't expecting the warning card, and it freaked me out a bit. 

[Phonesrfun]

My guess is that it had A-lead control on the second pair (Yellow and black), which was the way that a 1A2 business key system knew if a particular extension was taken off hook.

A phone these days is set up to normally only use the inside pair (red and green) for the phone for line one, and in the case where a residence has a second line, it is often brought in on the second pair, which often translates in the house wiring to the yellow and black pair.

Anyway, if your VoIP only uses the one pair, you are good to go.

-Bill Geurts

[Jim Stettler]

Another thing to consider: If you get sucked into the Hobby, you may need that extra pair for dial illumination on, 500 's, princesses or early trimlines. Then Again you may want to keep that Office desk phone correct in case you become a "switcher"(one who keeps and maintains telephone switches because they belong to C*NET).

Those guys collect telephone switches and have them all hooked up thru Voip. These switches can be small switchboard or KSU's, to complete operating Central Offices. Crossbar, step by step ect, compleate with proper office tones.

C*NET  all came about because of an IIQ.  Idle Internet Queastion.
"Wouldn't it be neat to network all these old switches thru the internet in leiu of Long Lines."


I beleive that the "telephone hacker" crowd also uses the C*NET network to play old-style telephone hacking. Everyone needs a Hobby.

They have all sorts of vintage switches, working together on a virtual network. Pretty COOL stuff. Think of it as a model telephone (train) layout. You have all these telephones and they work on your  command.
Now hook them all together and make a listserver to talk about what you are doing , and you have a prety neat set-up.

Kinda a digital "Hey Y'all, Watch this". Luckily they weren't in a group together drinking beer.

Maybe you shouldn't alter that office phone.

There are probably some switchers on this forum that might offer up some phone #'s for various office tones.

Jim S.
BTW I am not a Switcher, I am jus a Switcher wannabe.