If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Rate Thread | Display Modes |
#61
|
|||
|
|||
The internet is no longer any fun
On Mon, 18 Feb 2019 14:15:24 -0500, nospam
wrote: In article , lonelydad wrote: Some analog telephone adapters for Internet telephony require analog telephones with low REN, for example, the AT&T 210 is a basic phone which does not require an external electrical connection and has a REN of 0.9B. atas need to generate a 90v ring voltage from a (usually) 12v power supply, so it's no surprise it has more stringent requirements, plus only one phone is connected to a port. You can also plug the ATA into a wall jack, thus "lighting up" your entire house wiring and potentially multiple phones. Naturally, you'd disconnect your phone wiring at the demarc. |
Ads |
#62
|
|||
|
|||
The internet is no longer any fun
Mark Lloyd wrote in news
On 2/17/19 9:56 PM, nospam wrote: [snip] there was once a time when you couldn't do that in your own home. the phone company only allowed their phones, even with rj11 jacks, and they could tell if there were additional extensions you weren't paying for, which is why many phones were designed to not be detectable IIRC, the phone company could detect them by the additional ringer load. A phone would not be detectable if the ringer was disconnected. This would often be done if you had too many extensions (you don't need them all ringing anyway). When I was young, I spend a lot of time looking at the Radio Shack catalog, and remember those 4-prong plugs. I never saw them in use. What I did see a lot of looked like a 1/4-inch headphone jack. However, there was no jack but for some reason the installer had used a cover plate with a hole in it instead of a blank plate. That just allowed the phone company to make it more difficult to attach aditional phones, or add additional of the four prong jacks. Most people would be intimidated about opening up the box to get at the junction so they could add the wiring for additional jacks. Most of the time, there wasn't even a box behind the plate, just a collar on the wire so it couldn't be easily pulled from the plate. People in the know just went to the demarc and connected extra lines there. The 1/4 appearing headphone jack is where the nomenclature of 'tip and ring' for the two connections on jacks and plugs came from. In the days of manual switchboards, patch cables were used to connect the two subscriber phones together. 'Tip' obviously refered to the end contact, while 'ring' was the other contact. When these jacks and plugs were modified to handle stereo signals, the ring contact remained the other end of the plug from the tip, and a third contact was added between the two. This allowed mono headseats to still be connected to a stereo jack, since the ring contact was always right next to the interior end of the plug. Now with the advent of microphones with the headset, a fourth contact is also added. The equivalent contacts inside the jack are spaced so that there is compatabilty between mono, stereo, and stereo with mike. |
#63
|
|||
|
|||
The internet is no longer any fun
nospam wrote in
: In article , Mark Lloyd wrote: there was once a time when you couldn't do that in your own home. the phone company only allowed their phones, even with rj11 jacks, and they could tell if there were additional extensions you weren't paying for, which is why many phones were designed to not be detectable IIRC, the phone company could detect them by the additional ringer load. A phone would not be detectable if the ringer was disconnected. This would often be done if you had too many extensions (you don't need them all ringing anyway). they could, but they generally didn't care unless it was *much* higher. an extra phone is no big deal, but ten additional phones would likely be. the phone company also used to charge for touchtone, but what they didn't tell you is that nothing changed at their end, other than an additional fee. all the customer needed to do was connect a touchtone phone and it worked perfectly fine. the only exception was with step switches, which were too old to handle touchtone and didn't offer it as an option. Back in the day, we (wife and I) were too cheap to pay the additional fee for touch tone. I just went to Radio Shack and bought one of those touchtone pads that one held up against the mouthpiece. That worked for several years until the phone company was doing some kind of upgrade or survey, and found that I was doing that. So they just went ahead and added the additional fee whether I liked it or not. |
#64
|
|||
|
|||
The internet is no longer any fun
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256 Rene Lamontagne wrote: ... I don't remember what the Phone generator ring voltage was but the audio circuit in each phone was powered by 2 #6 cells for a total of 3.2 volts, The whole system was very reliable and never gave much trouble. If its anything like it was in the US (or, well, at least according to granddad's Western Electric book that I don't know who got ...), then it was most likely 36 or 48 volts, AC. -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEBcqaUD8uEzVNxUrujhHd8xJ5ooEFAlxrJN IACgkQjhHd8xJ5 ooGtCwf+Lkd+v7rpW7f24Qdzrplqsp4PsRGJkRggeLqzHTwfwP ft4m9/ub47tHxF 0bw4Q7Xew2qnFmoSOglyyQHlPxXaBbjtQWgd0rDrNty66CRaaF rSZLGcoRIyrlHK JPMoEJhIrSjYnIxlGVScWC7lpMhdby4HHe4l3SSm/UsN1trc2Vw+Ul7InOU406f+ Ch0sohZwpds/0Crm7q3TDePPyXyVmBtZ9szdf7JPiHMUSPIsPoQjgPAFPkkhRx yw 3HBWj8oi3YIJ7dVgpLtk99MQFUj96HFMnJuxk7Z8S8T4c60WHY E8aAM4hqPjsHRL /icLoJhFLCmBdDWglH31Wi00b2Zz0w== =tZbY -----END PGP SIGNATURE----- -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281 |
#65
|
|||
|
|||
The internet is no longer any fun
On 02/18/2019 3:34 PM, Dan Purgert wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Rene Lamontagne wrote: ... I don't remember what the Phone generator ring voltage was but the audio circuit in each phone was powered by 2 #6 cells for a total of 3.2 volts, The whole system was very reliable and never gave much trouble. If its anything like it was in the US (or, well, at least according to granddad's Western Electric book that I don't know who got ...), then it was most likely 36 or 48 volts, AC. -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEBcqaUD8uEzVNxUrujhHd8xJ5ooEFAlxrJN IACgkQjhHd8xJ5 ooGtCwf+Lkd+v7rpW7f24Qdzrplqsp4PsRGJkRggeLqzHTwfwP ft4m9/ub47tHxF 0bw4Q7Xew2qnFmoSOglyyQHlPxXaBbjtQWgd0rDrNty66CRaaF rSZLGcoRIyrlHK JPMoEJhIrSjYnIxlGVScWC7lpMhdby4HHe4l3SSm/UsN1trc2Vw+Ul7InOU406f+ Ch0sohZwpds/0Crm7q3TDePPyXyVmBtZ9szdf7JPiHMUSPIsPoQjgPAFPkkhRx yw 3HBWj8oi3YIJ7dVgpLtk99MQFUj96HFMnJuxk7Z8S8T4c60WHY E8aAM4hqPjsHRL /icLoJhFLCmBdDWglH31Wi00b2Zz0w== =tZbY -----END PGP SIGNATURE----- Hi Dan, I believe your right, the common POTS system was mostly 48 volts Even here in Winnipeg where I worked 1n the 80s and 90s our standby battery was a bank of 24 glass cells at 2 volts each making up the 48 volt bank. Rene s |
#66
|
|||
|
|||
The internet is no longer any fun
In article , Paul
wrote: And that's why you're not supposed to hold onto Tip and Ring. As if the -48VDC isn't enough of a warning. You will do the ChaChaCha if the 20Hz gets you. holding tip and ring at -48v doesn't hurt at all, but it does sting a little when it rings. been there, done that. Having held onto the Edmund Scientific hand-cranked generator (the one with the horseshoe magnets which makes 90V when you really crank it), you can actually shock about 20 people in series with that amount of voltage. that is not the same as a phone line. I imagine one person holding onto such a thing would be quite unpleasant for that person. That's probably why the ringing pattern alternates on and off, so the idiot holding Tip and Ring, can let go :-) no, that's not why. The DAA in telephone equipment has to withstand quite an ugly set of voltages to be compliant. It has to accept high voltage power lines falling against telephone lines. Without passing that to the user. So the 90V thing, isn't the end of spec-dom when you need to connect to a phone line. Obviously, telephone equipment doesn't survive a direct lighting hit. A carbon block or a gas tube will just explode, rather than protect you. But for lesser insults, the connection to the line has to be able to handle a lot more voltage than 90V. no it doesn't. if the voltage is too high, it will damage or destroy the phone or other equipment. It's the same with automotive electronics. You may think that the 12.6V battery means the operational requirements are 12.6V, but on a load dump, the DC rails can rise as high as 70V for short intervals. no they very definitely can't. vehicles are nominally 13.8v when the engine is running. it might spike a *little* higher but definitely nowhere near 70v. automotive battery chargers charge at around 14-15v, sometimes with a reconditioning cycle around 16-18v. in some cases, the battery should be disconnected because of potential damage to the vehicle's electronics. And if your car stereo manufacturer doesn't want a lot of warranty returns, the equipment has to "eat" that. A car electrical system isn't really "tightly regulated". It's a bad joke of an electrical system. it's not 'tightly regulated' but it works quite well for what it is. |
#67
|
|||
|
|||
The internet is no longer any fun
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256 Paul wrote: Dan Purgert wrote: Rene Lamontagne wrote: ... I don't remember what the Phone generator ring voltage was but the audio circuit in each phone was powered by 2 #6 cells for a total of 3.2 volts, The whole system was very reliable and never gave much trouble. If its anything like it was in the US (or, well, at least according to granddad's Western Electric book that I don't know who got ...), then it was most likely 36 or 48 volts, AC. The battery room in NA is -48VDC (-56V nominal). The battery room in Brazil is -80VDC. The Ringing Generator is higher than both those values and is AC. There are at least 20 different "country specs" for telephone voltages (the telephone switch needing to be programmed for the country it is in). https://en.wikipedia.org/wiki/Ringing_%28telephony%29 "These avoid the need to generate 20Hz 90V sinusoidal AC..." Indeed I was only thinking of the -48v nominal / standby voltage, rather than the 90VAC ring voltage. Been a long time since I've had to do POTS work. Kinda miss it (well, not the miles of white-orange / orange pairs). -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEBcqaUD8uEzVNxUrujhHd8xJ5ooEFAlxrWp YACgkQjhHd8xJ5 ooHPwAf/Qql4xJ58p3RDUbh6/jU793xdaqVXn1a7qSxb9trTU2YUFT8wTxH4kGpS kN3EnsbwGkzd8UhhMtJSRJVPc6grHVDHG1EBzDycAGwdqaX7FT nPcmb8TvbpXfdp G0xr7f5QlyhDEuL1mttYLNwY8606aFWpCWn0wbe7OaEeOWyl22 onxtJw9V1LlLSu q4QvFvWdxV9Pv5OjUUcOrOhEsSuuj2ydC44yGTSMBsAAWS21M3 WRxHfDm1wJt6vW BYhiuElEbPclSETp8gVZ1DPzTzyC5eVDsWffGFJTWk1LAJoFfe Y4gr2QkgsMfXen +r0oD6bHrK7R2Pu5q3El+AotZ01m0g== =NWJD -----END PGP SIGNATURE----- -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281 |
#68
|
|||
|
|||
The internet is no longer any fun
Dan Purgert wrote in :
Indeed I was only thinking of the -48v nominal / standby voltage, rather than the 90VAC ring voltage. Been a long time since I've had to do POTS work. Kinda miss it (well, not the miles of white-orange / orange pairs). Then you will probably appreciate this story. I attended a smaller college in rural Nebraska in the 70s. I spent one summer working for the Maintenence department doing a little of everything. That included digging a trench between the Maintenence building that contained the power access point for that portion of campus (transformers, meters, etc.) and another classroom building about sixty feet away, so that new conduit could be put down for the wiring upgrade in that building. We were digging that trench by hand because of all the other conduit and cables buried crossing that area. One thing we ran into was a concrete beam crossing the trench path. When we asked what that was for this is the answer we got. It seems that the phone company in town also served a good portion of the surrounding countryside. As such, a rather large aerial trunk cable came up to the downtown side of campus, then went underground. On the far side of campus it re-emerged and turned back into an aerial cable as it served all the customers in that directin from town. Further info was that there used to be a couple of campus buildings in the area that were no longer there. When the guys were digging a trench for some of the wiring we were avoiding, they ran across this steel conduit running across their trench. When they checked with the Maintenence manager, he told them that it was probably power lines that used to go to the now nonexistent buldings, and to get the SawzAll out. You guessed it. The guy who had been doing the sawing told me that he had cut through the conduit on one side, and started on the other. He said there were these funny little pieces of copper falling out of the cut. About the time he finished the cut and the center chunk fell down, the maintenence boss came by and said all the phones had stopped working. When they looked at the end of the conduit they saw a whole lot of ends of phone wires. Now this was about a three or four inch conduit, so a lot of wires. I don't know if they were color coded or the old plain paper wrap, but either way it took a while to get all the wires spliced. After that had occured they dug out the conduit for about ten feet in each direction from the trench, and buried it in concrete. Isn't life fun some times! I can just imagine what the phone guys said when they called this in. "You did what! Oh my G*d!" |
#69
|
|||
|
|||
The internet is no longer any fun
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256 lonelydad wrote: Dan Purgert wrote in : Indeed I was only thinking of the -48v nominal / standby voltage, rather than the 90VAC ring voltage. Been a long time since I've had to do POTS work. Kinda miss it (well, not the miles of white-orange / orange pairs). Then you will probably appreciate this story. [...] Ouch. That just makes my brain hurt. If that was laid after the 1950s (IIRC), at least they'd have the benefit of the "modern" binder groups / color coding scheme (although, I imagine there was SOMETHING in place before then as well). -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEBcqaUD8uEzVNxUrujhHd8xJ5ooEFAlxsGk MACgkQjhHd8xJ5 ooELzwf/VDZ/zMAfgdARHoP2iIZGt5ZBLvmAWRysWtACnX0ZtHR13QI56FINIm pj B+2DC+zG3FrbEZKqb+PF3z2MmUhWK8JL3je0tIwwAyvDtvdqPV kvToYteAvMqNbw gYeIogWoViJvu0CELlkRITX/ilY91tEIDAyvEMUdOQFiN5toSfUVAKwMizbu2Sak M21OckfSepJidObgf51wmUa5n0FcUqS0q3LVKiOEskdVw1E/8XdImk9xTJAL63P0 iIrCXSYpAI6o74B3/xusxPRS0u1xVo2QsPUnFaE8+xv1er05gl2YI/37js+zXcQ5 DnASjDaTz7+inLL01pXK0jP5TuKFTg== =XeDe -----END PGP SIGNATURE----- -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281 |
#70
|
|||
|
|||
The internet is no longer any fun
On 2/18/19 12:15 PM, nospam wrote:
[snip] the phone company also used to charge for touchtone, but what they didn't tell you is that nothing changed at their end, other than an additional fee. I remember when I first got one in 1982. There was a 50-cent charge on the bill for tone service. all the customer needed to do was connect a touchtone phone and it worked perfectly fine. the only exception was with step switches, which were too old to handle touchtone and didn't offer it as an option. In 1988 I moved to a different area. The phone system still had an old step stitch, with a translator to allow tone dialing. On my phone, you could push the buttons for 7-0212 for time and temperature (yes, local calls just needed 5 digits then), and then wait for the click-click-click-click-click-click-click click-click-click-click-click-click-click-click-click-click click-click click click-click. BTW, the 5-digit dialing went away in a couple of years when they went to electronic switching. Now, it's 10-digits for a local call (overlay area code). -- Mark Lloyd http://notstupid.us/ "War to the death against depravity--depravity is Christianity." [Nietzsche] |
#71
|
|||
|
|||
The internet is no longer any fun
On 2/18/19 1:58 PM, nospam wrote:
[snip] another was flip the polarity of the line, but that's easily fixed. IIRC, modern phones work just as well with either polarity. Maybe that's why they're like that. -- Mark Lloyd http://notstupid.us/ "War to the death against depravity--depravity is Christianity." [Nietzsche] |
#72
|
|||
|
|||
The internet is no longer any fun
In article , Mark Lloyd
wrote: the phone company also used to charge for touchtone, but what they didn't tell you is that nothing changed at their end, other than an additional fee. I remember when I first got one in 1982. There was a 50-cent charge on the bill for tone service. i recall it being higher where i was. all the customer needed to do was connect a touchtone phone and it worked perfectly fine. the only exception was with step switches, which were too old to handle touchtone and didn't offer it as an option. In 1988 I moved to a different area. The phone system still had an old step stitch, with a translator to allow tone dialing. yikes. step was fun in its day, but obsolete long before 1988. it did take a while to replace all of them, however. for crossbar, touchtone 'just worked'. On my phone, you could push the buttons for 7-0212 for time and temperature (yes, local calls just needed 5 digits then), and then wait for the click-click-click-click-click-click-click click-click-click-click-click-click-click-click-click-click click-click click click-click. crossbar didn't need to translate, although one advantage of step was the 5 digit dialing. BTW, the 5-digit dialing went away in a couple of years when they went to electronic switching. Now, it's 10-digits for a local call (overlay area code). 10 digit dialing is exactly as it should be. at least you don't have the braindead requirement of a 1 prefix. |
#73
|
|||
|
|||
The internet is no longer any fun
In article , Mark Lloyd
wrote: another was flip the polarity of the line, but that's easily fixed. IIRC, modern phones work just as well with either polarity. Maybe that's why they're like that. modern ones do, but the 500s didn't, which is what people had back then. |
#74
|
|||
|
|||
The internet is no longer any fun
On 2/18/19 4:00 PM, Rene Lamontagne wrote:
[snip] Â*Hi Dan, I believe your right, the common POTS system was mostly 48 volts Even here in Winnipeg where I worked 1n the 80s and 90s our standby battery was a bank of 24 glass cells at 2 volts each making up the 48 volt bank. Rene s I remember seeing those batteries at a major telephone exchange (Ft. Worth TX). Many of them came from old submarines. They also mentioned the computer that's used for directory assistance, but wouldn't let people in there. Apparently, the computer was very sensitive to heat. BTW, They would have more operators working on a day when there was wintry weather or a major football game. More people were using the phone then. -- Mark Lloyd http://notstupid.us/ "War to the death against depravity--depravity is Christianity." [Nietzsche] |
#75
|
|||
|
|||
The internet is no longer any fun
On 2/18/19 1:38 PM, lonelydad wrote:
[snip] That just allowed the phone company to make it more difficult to attach aditional phones, or add additional of the four prong jacks. Most people would be intimidated about opening up the box to get at the junction so they could add the wiring for additional jacks. Most of the time, there wasn't even a box behind the plate, just a collar on the wire so it couldn't be easily pulled from the plate. People in the know just went to the demarc and connected extra lines there. This house, built in 1969 had a hardwired wall phone in the kitchen, and wiring to the bedrooms. I remember someone saying you could have a phone you carry around and plug in in any bedroom, although we didn't. The 1/4 appearing headphone jack is where the nomenclature of 'tip and ring' for the two connections on jacks and plugs came from. In the days of manual switchboards, patch cables were used to connect the two subscriber phones together. 'Tip' obviously refered to the end contact, while 'ring' was the other contact. When these jacks and plugs were modified to handle stereo signals, the ring contact remained the other end of the plug from the tip, and a third contact was added between the two. This allowed mono headseats to still be connected to a stereo jack, since the ring contact was always right next to the interior end of the plug. Now with the advent of microphones with the headset, a fourth contact is also added. The equivalent contacts inside the jack are spaced so that there is compatabilty between mono, stereo, and stereo with mike. I've heard of, but not seen a newer one that has five contacts. I know about 1/4-inch jacks/plugs. What I found here had neither, just a wall plate with a HOLE in it (about the right size for such a plug). There was nothing in there but wires. The wires in this were six-conductor, colored like wire used for ethernet except no brown pair. I checked for dialtone using the speaker from a pocket radio, and IIRC found it on the blue pair. -- Mark Lloyd http://notstupid.us/ "War to the death against depravity--depravity is Christianity." [Nietzsche] |
Thread Tools | |
Display Modes | Rate This Thread |
|
|