I was checking a phone jack, and it said reverse polarity on my tester. I wired it correctly I was thinking, so I plug in a phone and I had a dial tone. I called the Ph.# also, and it rang. If I have a dial tone, then there was no need to call it also correct? I just remember tip & ring so I thought maybe I should call it. I really don't even know what tip & ring is. Anyway I checked another jack and it lighted green correct polarity. Any idea whats going on? Thank you for your help.
Phone jack tester
- Thread starter zappy
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mcclary's electrical
Senior Member
- Location
- VA
Is this a new home run? or could it be spliced wrong somewhere?
Yes it was a new homerun.
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Older Touch-Tone(tm) phones were polarity sensitive- the dial wouldn't work but otherwise they're work. Pretty much all POTS line devices made in the last 20 years have a "polarity guard" built in so it doesn't matter. I suppose there are still a few devices are sensitive to it, but very few.
The terms Tip and Ring come from the 3-conductor plug on a switchboard. The third conductor was Sleave. The talking goes over T and R, and the S is used only for switching supervision. The terms have hung around for, what, 80+ years.
The terms Tip and Ring come from the 3-conductor plug on a switchboard. The third conductor was Sleave. The talking goes over T and R, and the S is used only for switching supervision. The terms have hung around for, what, 80+ years.
Thanks. How about a fax machine, will it work?
kwired
Electron manager
- Location
- NE Nebraska
I have not seen a phone or fax or modem that cares about polarity of phone line in order to work.
Polarity is easily reversed when making your own device cordsets if you do not pay attention to which way you install the ends. I never pay attention to this and never have any problems.
As zbang said older equipment may be polarity sensitive.
Polarity is easily reversed when making your own device cordsets if you do not pay attention to which way you install the ends. I never pay attention to this and never have any problems.
As zbang said older equipment may be polarity sensitive.
luckylerado
Senior Member
- Location
- Lake of the Ozarks
Most electrical appliances do not care about polarity either but I bet none of you hook up your receptacles backwards. The fact is that some systems are polarity sensitive and it is always better to do it right the first time. Take the time to know.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Most phones made in the last 20 years (maybe more) or so arent polarity sensitive.
That started with the breakup of the phone company which brought the modular cord system. Take a look at modular cords and all the adapters available and you will see that the polarity will be reversed each time a cord is plugged into something. So polarity is not an issue today at least for anything that uses a modular jack. Still it is proper workmanship to get the polarity right at a wall jack and if it is correct at the demarc, observing the proper color code throughout the premises wiring should make that a no-brainer. But sometimes somebody will do a hack job and use modular plugs, line cordage and modular adapters for premises wiring. If you find that don't expect the polarity to be correct.
-Hal
That started with the breakup of the phone company which brought the modular cord system. Take a look at modular cords and all the adapters available and you will see that the polarity will be reversed each time a cord is plugged into something. So polarity is not an issue today at least for anything that uses a modular jack. Still it is proper workmanship to get the polarity right at a wall jack and if it is correct at the demarc, observing the proper color code throughout the premises wiring should make that a no-brainer. But sometimes somebody will do a hack job and use modular plugs, line cordage and modular adapters for premises wiring. If you find that don't expect the polarity to be correct.
-Hal
TOOL_5150
Senior Member
- Location
- bay area, ca
so does TRS really mean Talk, Ring, and switch - then changed to tip-, ring, sleave?
~Matt
MichaelGP3
Senior Member
- Location
- San Francisco bay area
- Occupation
- Fire Alarm Technician
Sleeve, not sleave.
TOOL_5150
Senior Member
- Location
- bay area, ca
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Nope, merely the three contacts.
The old switchboard plugs were similar to, but not exactly like, today's 1/4" stereo headphone plugs. The tip is the left channel (or mono) contact, the ring is the right channel, and the sleeve is the common, the ground, the body.
Added: TRS also means (or, meant) Tandy Radio Shack, as in the Trash-80 computer.
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Volta
Senior Member
- Location
- Columbus, Ohio
'Tis Really So?
kwired
Electron manager
- Location
- NE Nebraska
Anybody that knows about the Trash 80 has been around computers for a while
Jerry the Phone Guy
Member
- Location
- Jamaica, NY
90% of the time, tip-ring polarity makes no difference for phones, but, old pre-divestiture equipment with a touch tone keypad (stuff made between 1965-1984), won't dial with the wrong polarity.
So, it's a non-issue with modern single-line phones, but, some phone systems require consistent polarity to switch calls between extensions, because they use the "phantom pair" that exists between two pairs.
And obviously, T1, ISDN and Cat 3/5/6 Ethernet LAN jacks have to have all 4 pairs properly polarized, so, it's a good idea to develop good work habits now.
After all, the code does require the job to be neat and workmanlike.
So, it's a non-issue with modern single-line phones, but, some phone systems require consistent polarity to switch calls between extensions, because they use the "phantom pair" that exists between two pairs.
And obviously, T1, ISDN and Cat 3/5/6 Ethernet LAN jacks have to have all 4 pairs properly polarized, so, it's a good idea to develop good work habits now.
After all, the code does require the job to be neat and workmanlike.
The rotary phones in my house when growing up had 3 wires, RG+Y. If you left the yellow off, it wouldn't ring. That's back in the days when they charged per # of phones in the house, leaving off the yellow would make add'l phones undetectable by keeping the load down when the electro-mechanical bells rang.
Volta + Kwired, at my wife's office (matrimonial lawyers), they used trs-80's with their 8" floppy disks for years running wordperfect.
Volta + Kwired, at my wife's office (matrimonial lawyers), they used trs-80's with their 8" floppy disks for years running wordperfect.
Jerry the Phone Guy
Member
- Location
- Jamaica, NY
Paul-
That yellow wire is used as an earth ground to polarize the ringer when used over a party line.
As for using 'old computers', I say, iffen it ain't broke, don't fix it.
That yellow wire is used as an earth ground to polarize the ringer when used over a party line.
As for using 'old computers', I say, iffen it ain't broke, don't fix it.
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