Does FiOS support rotary phones? [telecom]

I believe undersea fiber optic cables actually carry something like several kW of power over kilo-mile distances via copper that's embedded in the fiber optic cable, in order to power the EDFAs (Erbium Doped Fiber Amplifiers) that are spliced into the cable every 50 km or so.

So, the fiber cables for FTTH could certainly contain a copper pair or two to deliver low-power AC or DC all the way to the premises end. Wouldn't significantly increase the size or flexibility of the cable, I'd guess. Would add noticeably to the cost of the cable, however, along with the cost of spllcing or connectorizing the cables -- and somebody would have to be responsible for supplying the power.

I'd bet that if one were installing the communication infrastructure in some large green-fields development, it might make overall economic sense to run a single cable containing a PON fiber plus a few pairs of copper to every premises, using the fiber for all forms of large-scale communications and data, and the copper to supply backup or emergency power for crucial parts of the whole infrastructure, plus a few low-data-rate communications applications such as various monitoring and alarm systems and maybe meter reading.

Reply to
AES
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Another disadvantage of local battery was the lack of supervisory signals on the switchboard. Subscribers were supposed to ring off when done but most forgot.

There was an army technical manual, "Fundamentals of Telephony" that had an excellent explanation of the differences between local battery (hand cranked) and common battery (switchhook signal) telephone sets and switchboards.

If memory serves, common battery required a more complex switchboard than local battery. A local battery indicator was a tiny shutter drop released by the subscriber's magneto. No lamp, no relays, so a simpler switchboard. Also, I believe local battery permitted longer loops than common battery, and probably the wire didn't have to be in as good condition. Lastly, when I was a kid experimenting with No. 6 dry cells they lasted forever, so I don't think service visits to change the battery were required very often.

I don't know when local battery ceased to be a _significant_ type of commercial telephone service. Anyone know? I do know some railroads and street railways used it for internal communications well into the

1970s. They had modern-looking telephone sets--it looked like a 500 set except with a handcrank where the dial would go and the handset had a push-to-talk button.

I don't think FIOS would work with local battery phones . (Interesting on how we've gone full circle with a local battery). However, an enthusiastic salesperson just might tell you it would to make a sale, just as one told me DSL would work fine on a party line.

Not long ago someone posted an ad from a company in India that made local battery telephone equipment. Unfortunately, it didn't have pricing or a US dealer. But there's a lot of old local battery phones available.

***** Moderator's Note *****

There are usually military-surplus "field" phones on Epay. My brother has a TA-312 model, for which he was able to obtain, believe it or not, an official government-issue touch tone pad, which fits over the top of the phone and has a plastic barrier to remind users not to crank the magneto. Go figure.

Interestingly, when I just did a search for "field phone" there, the search produced listings for "Spirit of Saint Louis" "field phones" that look like children's toys but are claimed to be actual telephones: maybe something from the steampunk crowd, but YMMV. They're definitely not local-battery sets.

Bill Horne Moderator

Reply to
Lisa or Jeff

I had done a seach for "field phone" on Ebay, and I was about to redirect my browser to another page when I noticed an ebay listing for a ta-263/pt field phone. The listing says it comes with two linesman's whistles, and has a picture of them.

Somebody, please make my day: tell me the frequencies of those whistles. Ghod, please, let one of them be 2600. I'll laugh for a whole day.

Bill

Reply to
Bill Horne

ATT has U-Verse and a new "iNID" (short for "intelligent network interface device") for same...

In a note to the alarm industry, they say:

However, Pulse-Dialing is not supported by AT&T U-verse Voice. Only monitored alarm panels that support Touch-Tone dialing should be used.

I'm not clear on what the iNED does {not} do. It appears it bonds 2 pair back to the 52B U-verse coffin, and on your side it has POTS, TV and TCP/IP out with the TCP/IP going inside via HPNA over coax [vice MOCA over coax...].

Reply to
David Lesher

Bill, I wish I could make your day on this one, but those particular whistles do not do 2600 Hz. One of them was indeed intended for SF trunk signaling, but at 1600 Hz. The other whistle made a 1000 Hz tone that was pulsed at 20 hertz. The TA-263 itself was actually a TA-43 field phone combined with a low-pass filter and [4-wire] matching network that allowed a tech in the field to clip on to [open wire] analog carrier trunks without disturbing the active traffic.

The whistles, of course, were used to replicate the in-band ringing and trunk seizure signals used by the carrier systems, and set up paths by which a crew in the field could talk to the CO end[s]. Note that the link that was set up was just a straight voice-band connection, the phone did not communicate using carrier. I can not begin to guess whether it was possible to actually seize trunks and set up routes with the 1600 hertz SF tone [toot?], or if was merely used to ring-down the distant end.

Now, if you really want a field phone that can do 2600 Hz, there is at least one that I know of [and there could be others]. The TA-341 wasn't actually a field unit, but it was ruggedized. It is also the only Army phone I have ever seen that is painted a lovely Navy grey. It is a desk phone, designed for connection to the 4 wire lines that were commonly used by the military and government in the Autovon era. Note that these were not carrier trunks, but were often long-haul and could include voice-band repeaters. The TA-341 can do 1000 hertz ring signaling, and can also speak 2600 hertz SF. Amazingly, it does not have an Autovon keypad.

Jim Bennett

************************************************** Speaking from a secure undisclosed location.

***** Moderator's Note *****

Jim, thank you for the info. I would like to know a little bit more, not only about the ta-341 that you mention, but about "field" phones in general. For those of us whom are facing their second childhood and are considering higher-priced toys, please tell me which phones I can hook up to my POTS line and use.

I mentioned my brother having a ta-312 phone, to which he added a touch-tone adapter (it's a ta-955/pt, btw). It works fine on his home phone line, and is too heavy & old-looking for his kids to take, so he likes it. I might get one myself, since the cordless phone I usually use is never at the base station when I need it, and I'm tired of going on safari chasing the mating call of the elusive horned owlet. ;-)

Bill Horne Moderator

Reply to
AJB Telecom

Bill, Military surplus field phones were once so plentiful that surplus dealers would purchase them by the skid load. Now days, as the local "Army-Navy" store has all but disappeared, the best place to find them is ebay [of course], and on-line surplus dealers. Condition ranges from NOS [New Old Stock] to "usable for parts only," and the prices are all over the map.

The TA-312/PT that your brother has was probably the most plentiful on the surplus market, being part of the second-to-last generation of non- digital field phones [the *final* generation of analog equipment never made it onto the surplus market in any great numbers, for reasons I never completely understood]. It was also the most "bulletproof" of all field phones, and surprisingly heavy for such a small unit. While it was primarily designed to be used with a magneto switchboard [or with another 312, point-to-point only], it will work well on a POTS line. The TA-955/PT keypad is a nice addition, but even without it the phone can still be used to answer calls.

The TA-838 was the successor to the TA-312, and was part of the final generation of non-digital wireline comms equipment used by the various branches of the service. This entire generation of equipment never made it into the surplus market in the same way as previous equipment, making the 838 somewhat elusive. It is a nice phone, and certainly far more versatile that the 312. It will work on a standard 2-wire POTS line, on a magneto switchboard, point-to-point with another 838 or 312 [or others], on an automatic "tactical" switch using AC or DC signaling, on 4-wire lines [including Autovon], connected to a radio link with the necessary adapters, and probably several more modes of operation that I have never even heard of. All of this versatility comes with a price, however: if you look inside a TA-838, you will find a circuit board with a micro-controller on it, making it far more complex and expensive to repair than a 312. The 838 is still a very desirable phone, if you are lucky enough to find one at a good price.

The TA-341, mentioned in my previous post, was part of the earlier generation of analog phones and was once quite plentiful on the surplus market. It is not strictly a "field" phone, but it was designed to be used with an automatic tactical switch. Tactical switches, as the name implies, were used primarily "in-theater" only, being intended for temporary phone systems [some of which could get quite large and be set up and used for years]. The 341 is another multi-mode phone, and can use AC or DC signaling, making connection to a POTS line possible. It is also capable of 4-wire operation, but being intended primarily for use with a tactical switch, it does not have an Autovon keypad. While it is far more rugged than a typical desk phone, it is only intended to be installed in a sheltered area, out of the weather.

There are other field phones, of course, but most of them are rare and not likely to turn up on the surplus market in any great number. There are also much older generations of Military phones, these are usually much sought after by collectors and the prices sometimes very high. You will also notice a fair amount of digital wireline comms equipment on the surplus market. This is all first-generation digital equipment, things for which obsolescence came too quickly indeed. They can be readily discerned from their analog predecessors by the naming - the name plate will say things like: "Digital Non-Secure Voice Terminal." Needless to say, these are intended for use with a digital tactical switch and are completely useless without one, except that some of them are capable of direct connection to another DVT for a point-to-point system. The TA-1042 DNSVT apparently became obsolete so quickly that entire truckloads of them, new-in-the-box, turned up on the secondary market about ten years ago. They can still be found, and a pair of them will operate point-to-point, requiring only a power supply. Note that the first-generation Military digital phones are *not* IP phones.

Lastly, here are a couple of links:

"The Phone Lady" has a page with some pictures and descriptions of the phones mentioned above. It continues across several pages, so be sure to scroll all the way to the bottom of the page for the continuation links:

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Brooke Clarke has some excellent information on his web site, but the pages have not been updated in a while and most of the links no longer work, including a broken link to Telecom Digest. He does have info on connecting the phones mentioned above:

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Jim

************************************************** Speaking from a secure undisclosed location.

***** Moderator's Note *****

Jim, I appreciate the info. I'll check out the phones you mentioned, and maybe even get one for a conversation piece.

Please answer these questions for me and the other readers:

  1. Why were Autovan phones designed for four wire connections?

  1. Were the "Digital Non-Secure Voice Terminals" actually ISDN sets?

  2. Are any of the switchboards or other systems that these phones connected to available on the surplus market? I'm not looking to take over Radar O'Reilly's job, but I wonder if these "DNSVT" units connected to the equivalent of a small-business PBX.

  1. Are repairs or parts available for any of the more recent models?

TIA.

Bill Horne Moderator

Reply to
Jim Bennett

Another source might be via the two phone collectors' groups, ATCA and TCI. There's also Ron Knappen's telephone supply in Wisconsin.

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atcaonline.com

As mentioned, the military wasn't the only user of hand-crank (local battery) phones; railroads used them as did others. I believe they were made commercially into the 1970s and there was a post here about a company in India making them today.

Reply to
Lisa or Jeff

autovOn.... AUTOmatic VOice Network

They were 4-wire to allegedly offer far better transmission & conferencing than possible with lots of hybrids at far ends of the earth. This in an era well before exotic DSP-based cancellers/conference systems were dreamed of.

They also were thinking of connection to half duplex radio links, etc.

All good in theory, but friends who used same said the levels were so low, you could barely hear.

It got messy when a phone was both 2 & 4 wire, depending on what line you used. [SecDef/Oval Office Call Directors, etc.]

Reply to
David Lesher

Bill [our moderator] asked:

The short answer is that they didn't have to be four-wire. Many subscriber sets connected to the Autovon network were ordinary two-wire phones, connected to a PBX or through Centrex lines to a local switching center, which then connected to the Autovon network through special, dedicated trunk interfaces.

The long answer includes some facts and a bit of conjecture. A subscriber set that connected directly to an Autovon switch was indeed a four-wire instrument, with a different internal network in the phone [lacking the "hybrid" transformer arrangement found in a typical POTS phone]. The standard explanation for this is that these subscribers were located a long distance from the Autovon switch, and the trunks were four-wire for the same reasons that all long-distance circuits have a separate transmit and receive path, i.e., the need for carrier systems and/or repeaters, which are easier to design and build when they do not have to be bi-directional [which they would need to be on a single pair], and the issue of echo cancellation [a huge problem on a long single-pair trunk]. Additional premise equipment was needed at a subscriber location in order to connect directly to an Autovon switch. In addition to the signaling system needed to place calls over a trunk [they used SF, and, on shorter circuits, DX signaling on a separate E&M pair], there was also a special interface required to handle call priority. [1]

But now the answer gets even longer: The Autovon switches themselves are [were] referred to in the available literature as "four wire switches." Indeed, the crossbar switches originally used were in fact modified, and the 1AESS that replaced crossbar in Autovon was also a "special," with very different programming from a standard ESS. Much of the differences had to do with the actual route selection matrix, which was remarkably complex and could re-route circuits to bypass switching nodes and circuit paths that were down. This concept will likely sound quite familiar today - it is, of course, part of the basis of how the internet works. DARPA simply built on decades of existing developments that were all driven by the impetus of the Cold War.

It is this reference to "four-wire switches" that leads to the conjecture that makes this answer so long. While I cannot produce any documentation to prove this, it has always been my belief that Autovon switches had the ability to treat the transmit and receive paths of a telephone call as completely separate circuits. In an ordinary toll switch, the two circuits that carry to two sides of a conversation are always handled and switched together as a unit, and will both travel over the same physical route. I will leave it as an exercise to the reader to conclude why the Autovon system would wish to treat the transmit and receive pairs [and their long-haul circuit routes] as distinctly separate. Officially, however, Autovon was always described as a "non-secure" system, and was [supposedly] never intended to carry "top secret" conversations. Proving [or disproving] any or all of this theory could be a challenge: While Autovon has been out of service for almost two decades, much of the official documentation regarding its operation remains classified to this day. On his website, "A Secert Landscape,"[2] Albert LaFrance has copies of two lists of Autovon related documents that were furnished by the DoD's DTIC [Defense Technical Information Center] in response to a Freedom of Information Act request. The first is the list of documents that have been "approved for public release," and it runs about fifty pages. The second list, which contains those documents that remain classified ["distribution restricted" in DoD-speak] runs some two hundred pages.[3]

Bill continued:

As you know, ISDN does not actually specify a physical circuit type, but I assume that you are referring to a typical ISDN phone in North America, which connects to the CO over a four-wire circuit [two 64 kbps channels, one transmit and one receive], essentially a single DS0 encoded using 2B1Q. The Digital Voice Terminal field phones used by the Army actually used a 16 kbps CVSD [Continuously Variable Slope Delta] coding technique for the actual talk path, and 16 or 32 bit conditioned diphase [sometimes called "differential Manchester encoding"] for call set-up and signaling. Some commercially available electronic key systems use CVSD for the talk path, and when this question came up a couple of years back on a popular interconnect forum, I questioned whether such a key system could be adapted to work with these phones. About a year after the thread first ran, an Army Signal Corps veteran posted to describe what was actually required to connect one of these phones to the PSTN: In addition to converting the talk path, you must of course also interface the call setup and signaling, and based on this person's comments it seems that there is no easy way to do this without the actual equipment used by the Service.

As far as whether this equipment is available on the surplus market, that is an excellent question. As you know, surfing the global internets using our favorite search engine reveals that many of the common search terms for this sort of thing have been usurped by "content farm" sites and others that have nothing to do with Military phones, and exist only to try and sell you something completely unrelated [insert long sigh here]. If anyone knows of any legitimate surplus dealers that carry this equipment at a reasonable price, please let us all know!

Bill also asked:

The best bet for repair parts for any Military phone is to cannibalize an identical unit. This is why it never hurts to buy one that is battered and incomplete, if the price is right and you have [or will have] a "good" one. In addition to ebay and actual surplus dealers, this equipment and parts for it often turn up at Ham shows, "old-school" computer shows, and even shows for Military vehicle collectors. I don't know of anyone that offers repairs for this equipment, but they may exist, so again I would ask that if anyone knows of them, please let us all know.

And now, [drum roll, please] the end notes: [1] For an example of the additional premise equipment required to connect directly to an Autovon switching center, see BSP 981-210-100 [if the following is split into two lines, you may need to paste them into a text editor and splice it back together to use the link]:

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[2] "A Secret Landscape" is found at:
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. Also see Albert's other excellent site:
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.

[3] This will come as no surprise to anyone who has ever looked for certain info regarding telecom and the Armed Services, as the DoD has always played it very close to the vest in this area. Some people may be amazed to discover that they can find a manual for their new mil-surplus machine gun in about 30 seconds, but days of searching can't turn up a manual for their ancient field phone. For example, the TA-1 phone is basically a butt-set with a built in magneto and a dynamic [sound powered] transmitter element. It is considered an antique now, but the manual for it remains "restricted" to this day. I keep mine locked in the safe, next to the launch codes. ;)

Jim Bennett

************************************************** Speaking from a secure undisclosed location.
Reply to
Jim Bennett

In article ,

This one I can contribute on:

(There were separate pairs for tx and rx, obviously, thus --)

no need for echo cancellers on long circuits.

easier interface to radio links.

better control of signal levels -- _very_ useful for multi-party calls.

Reply to
Robert Bonomi

You've missed the main problem with powered copper - water. Water WILL get into the cable, no matter how fancy the connector and how properly it is torqued. It may take 50 years if done right or a few days if done wrong, but water always wins. Once the water is in the metal starts corroding. Powered cables corrode much faster than unpowered ones. Then, they stop working or pass noisy signals.

In short, water is the bane of powered copper installations and is one of the big reasons PON (Passive Optical Network - Ed.) is so much more reliable than copper. With nothing powered between the OLT and ONT, there is nothing to get damaged by water. When my FiOS drop was installed, the installer literally fished the drop cable out of a foot of water in the access vault, removed the protective cap from the drop cable, screwed on the fiber to my house, and dropped the whole thing back in the water. Even when water seeps into this connection, it'll have little effect on the glass and plastic fiber cable assembly.

If we start passing power along with the fiber, the eliminates one of the major advantages of PON - lower maintenance costs due to no powered stuff in the field.

Now, I did see that the drop cable does have a ground wire attached to it. It is grounded at the access vault and my house. It's purpose is to allow the cable to be located. It doesn't pass power or signal. Even if it corrodes (and it will), it'll still show up when the cable locator is passed over it.

-Gary

Reply to
Gary

...... And fibre doesn't propagate massive spikes from induced lightening strikes into your equipment the way metal conductors do.

Reply to
David Clayton

A valid point. Lightning problems are rare here in the SF Bay Area, but I understand are a serious issue in many other locations.

Reply to
AES

Most people still don't understand that a lightening strike hitting the ground in their vicinity can cause a massive spike in their metal phone lines - which essentially act as massive antennas - which end up affecting whatever is connected at either end. This can occur many miles away from people but it can still affect them.

The Telcos have significant line protection to keep these nasties out of their expensive electronic equipment, how many end-users have similar protection at their ends?

People still complain about their ISP after storms in their area or bellyache about their "crap" ADSL modems which - coincidently - seems to either fail or degrade in performance after these self-same storms. Ignorance is good business for the manufactures of anything connected to the copper phone network - this may go away with fibre.

Reply to
David Clayton

In the U.S., with POTS service, virtually _all_ end-users have basic protection against such 'at the DEMMARC', provided by the telco.

There are multiple reasons for the telco providing it. For starters:

1) given a strike _on_ telco wiring, with a surge following the telco wiring into the property, and possibly injuring someone inside, the telco _does_ have legal liability. 2) if there is a strike on the end-user property, the telco doesn't want that surge 'backing up' into the telco system, and blowing out lots of other customer pairs.

The only weather-related DSL problems I've known of were where a multi- pair distribution cable had a moisture problem. After a hard rain some water would get into the cable, and cross-talk issues would go _way_ up. wait a few days, the damp spot dried out and things were back to normal. Well, until the next rain.

Reply to
Robert Bonomi

I was always rather aware of that. As a kid, we had a summer cottage whose phone was on a 2 party party line. The ringer was connected between one of the two leads and the ground stake, not between the two leads. Whenever a thunderstorm was nearby the phone would ring, usually just a 'ding' in synch with a lightning stroke. (actually the phone would tend to ring more after the storm passed over us and was to the east) We'd joke, "Mr. Lightning calling, don't answer it!"

Reply to
Michael Moroney

Our apt building has no such protection. I've lost a few modems from lightning strikes a distance a distance away, as others mentioned. Several of my neighbors were affected too during the same storm.

I believe the telco differentiates between aerial drops and underground drops. AFAIK, subscribers served by a line from a pole to their house has protection on it to protect the wiring from the lightning-power currents that could cause a fire. However, AFAIK underground lines would not send out current that would be enough to start a fire or even damage old style Western Electric phones, so protection is not provided.

Not every subscriber has a demarc box. Our complex does not have them, and I understand that situation is typical for such older buildings. On the exterior of the building is a large telco junction box, which serves as a mini-distributing frame connecting the underground cable to the lines that serve each apt. Residents do not have access to that junction box.

For 99% of the residents not having a demarc is not an issue. They plug a phone into the jack on the wall and that's it. One time I had bad static on the line and I reported it. The telco got back to me that it was fixed "put on a different pair", but the fix was completely transparent to me and at no charge. The same thing happened to a neighbor in a different building.

As mentioned, the condo board will not allow the telco to put FIOS in here because the board fears the external boxes will be ugly. I'm not sure that's a valid concern since this thread suggests the FIOS boxes could be installed in the building rear. But then they had trouble getting the cable company to install wires properly and discretely as they promised to do, not run them across sidewalks or thrown over a roof as they did.

All underground wiring was a big deal in the 1970s, but it has some drawbacks. Contractors screw up and cut phone lines despite being warned to check first. Winter freeze/thaw cycles can break electric power cables and that's very costly to provide. The original underground transformers had overheating and moisture problems.

Reply to
Lisa or Jeff

Basic electronic equipment - like ADSL modems - invariably have little protection to surges and even small ones can cumulatively degrade performance.

*always* people complaining immediately after storms in every ISP's individual forum. When you took a broader look at the complaints at a regional level you could then see the pattern, and the subsequent dissatisfaction with things until - magically - replacing the ADSL modem seemed to fix all issues.

As I said before, good business for the modem manufacturers who sell the replacements and maybe also those who also sell protection devices for the incoming phone line (which aren't common in Australia).

Reply to
David Clayton

The telco-supplied protection is designed to prevent life-threatening situations into the premises, and _wiring_ threatening surges from propagating back to the network.

'Minor' excesses, can easily 'fry' many types of CPE without triggering the "life-saving" gear.

Every installation _does_ have a DEMARC. Whether or not it is a distinct 'box' is irrelevant.

I'm willing to bet that there are "circuit protective" devices inside that box. They may be as simple as passing bare wire "close" to a ground bus, so that a life-threatening surge/spike will jump the gap and short to ground.

I repeat, -every- customer circuit has a DEMARC. It always exists, because it is defined by statute and utility commission rules/regulations. Whether or not there is a 'box' there -- with, or without a customer- accessible test-point -- is irrelevant to the existence of the DEMARC.

[Moderator snip]
Reply to
Robert Bonomi

It is surprising that modern 'digital' telephone systems often don't support rotary-dial, since rotary-dial is a digital system. It uses pulse count modulation. In the U.S., there is one pulse for a 1, and ten for a 0, and respective for all other numbers. Regardless of being electronic or mechanical, it is sending out a series of 'bits' that are counted by either an electronic or electro-mechanical system. Most modern POTS systems use computers instead of cross-bar switches, and are fully capable of recognizing POTS. I also have dialed a very rare few business whose automated telephone systems do in fact recognize pulse-count modulation. There is no good reason why more systems don't support rotary-dial other than they are fond of making a legacy system obsolete, which seems to please so many die-hard modernists. The rotary-dial system is, however, the first fully automated digital dialing system, as Philco's rotary-dial Mystery Control was the first wireless all-digital remote control.

Reply to
bigbadpiratetom

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