Author Topic: Setting up a home rotary phone network/switching system  (Read 1589 times)

Offline briantroutman

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Setting up a home rotary phone network/switching system
« on: February 13, 2018, 02:42:35 PM »
Hello-

I’m new to Classic Rotary Phones—both the website and the hobby. But I’ve long been interested in old phones, and I’m particularly fascinated by the electromechanical switching systems that were disappearing in my area just as I first began using telephones as a young child in the late ’80s.

Perhaps because now even the public copper phone network itself is starting to disappear—and because I have a young child of my own and would like to introduce her to some of the old technologies that I grew up with—I’d like to set up a network of rotary phones in my own home. Again, I’m new to this, and admittedly my knowledge is limited, so perhaps it would help if I broke my “wish list” into tiers based on priority, and we can discuss what would be technically, financially, and practically feasible.

Tier 1 - Basic voice connection
At a very base level, I’d like to have two WE-500-type rotary phones that I can wire together and use to talk from one to the other (like a two-way intercom). I understand this is fairly easy to do with wiring, a lantern battery, and a resistor. If possible, it would be preferable to supply the necessary DC talking current from household power so that I’m not constantly consuming batteries.

Tier 2 - Ringing
Another fairly base wish list item would be the ability to ring one phone from the other (even if this meant needing to press a separate doorbell-like “ring” button in order to do so). From my preliminary research, it seems the challenge would be generating the 90v/20Hz AC required to power the bell. I’ve encountered widely differing opinions on whether using straight 110v/60Hz current is or is not dangerous for either the phones or the users.

Tier 3 - “Pseudo” switching
At the next level, it would be very nice to be able to dial Phone B from Phone A—even if it was as simple as dialing a single digit to establish a connection between the two.

Some years ago, I saw a demonstration from a Canadian science program that gave me my first bit of education on how phones and mechanical switching work. (Here’s a link to that clip: https://youtu.be/uHGmckJMcAc). In that video, the host has some kind of rotary stepping switch wired into the circuit that he describes as being “part of an old jukebox”. The arm is parked when the phone is on-hook, moves one position for each pulse, then parks as soon as the phone is hung up. Perhaps I’m oversimplifying, but if I had such a switch and wired Phone B into the seventh contact, for example, wouldn’t it be possible to pick up Phone A, dial 7, then speak to Phone B? Of course this wouldn’t automatically generate a ring, and there would be no dial tone—and I assume it would only be possible to dial from A to B...but not the reverse.

Tier 4 - “Real” switching/expansion
Of course my ultimate desire would be to have everything—dial tone, unique numbers for Phones A and B, the ability to dial between phones, and the option to eventually add a few other phones and run wires through the house so that I could, say, call the kitchen from the garage. I don’t anticipate that connecting my personal phone network to the PSTN will ever be a major consideration.

Perhaps the easiest and cleanest solution that would give me all wish list items at once would be to get some kind of a small, older PBX system (I’m assuming circa 1980s-’90s) and use it to connect rotary handsets. I have to say, though, that the idea of using a completely electronic PBX does take some of the allure out the proposition. And I’ve also seen videos of setups where rotary phones are connected in an internal network via a PBX, and after the rotary phone is used to dial the other phone’s extension digits, the PBX audibly repeats the dialing digits as DTMF tones. That’s something else I wouldn’t prefer to have, but if the alternatives would be impossibly difficult to set up or maintain—or very expensive—a PBX might be the best overall option.

I’ve also seen some videos of older (I’m assuming ’50s-’60s) mechanical PAX systems in operation, and they might be more along the lines of what I had in mind, although I wonder if such a system would be virtually impossible to find, particularly costly, or very difficult to keep running. Another consideration is space; I’m in an apartment currently (as my wife and I consider purchase options in our town), so a refrigerator-sized unit wouldn’t be practical in the short term. I’ll likely purchasing a detached home with a basement in a few years, so accommodating larger switching equipment and running wires would be possible later on.

I look forward to your input and advice! Many thanks in advance.

Offline Babybearjs

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Re: Setting up a home rotary phone network/switching system
« Reply #1 on: February 13, 2018, 03:03:40 PM »
it can get to be quite time consuming and takes a lot of reading and research.... I have a small 1A1 system with a 9 station intercom... works for me... go to the TCI Library at www.telephonecollectors.info and start there. this forum can help also... plenty of old timers who love to play with phones....(like kids in a candy store....) building a system from the ground up takes a lot of wiring and patients... plus plenty of time and money.... ask any questions and we'll try to answer them as best as possible....
John

Offline AE_Collector

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Re: Setting up a home rotary phone network/switching system
« Reply #2 on: February 13, 2018, 03:31:37 PM »
This is a repeat but here goes anyway:

Forget compact and modern, go BIG and get a REAL PABX.

Might I suggest this Hitachi GTX400 Crossbar PBX. This one will run 400 of your favorite rotary phones and should support 100 trunks just incase you have lots of traffic. Your existing electrical service in your house should handle it but you may have to limit use of things like the clothes dryer, stove and heating while you are playing with your phones..

The best news...I know where this one is and it is ready to be picked up and moved to your home!

Here’s the link where I posted this previously:
http://www.classicrotaryphones.com/forum/index.php?topic=2124.msg34273#msg34273

Terry
« Last Edit: February 14, 2018, 11:35:01 AM by AE_Collector »

Offline Babybearjs

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Re: Setting up a home rotary phone network/switching system
« Reply #3 on: February 13, 2018, 03:41:34 PM »
Boy Terry..... you sure do like a lot of telephone! have you ever had to wire one of those?
John

Offline AE_Collector

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Re: Setting up a home rotary phone network/switching system
« Reply #4 on: February 13, 2018, 03:44:26 PM »
They were sort of modular...boxes and boxes of plug ended cables. I took out way more than I ever worked on though I recall adding a 100 Station line frame to an existing system once. All back in the 70’s. I know where this one is abandoned near here but can’t even think about doing anything about it!

I would sure like to hear one processing calls again though!

Terry

Offline HarrySmith

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Re: Setting up a home rotary phone network/switching system
« Reply #5 on: February 13, 2018, 03:51:45 PM »
OK, Terry, you talked me into it. Just drop it off here in Coral Springs next time you are down!
Harry Smith
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Offline AE_Collector

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Re: Setting up a home rotary phone network/switching system
« Reply #6 on: February 13, 2018, 03:56:02 PM »
I’ll watch for the next Vancouver to Fort Lauderdale Panama Canal Cruise and take it onboard in my luggage. You’ve got to pick up at Port Everglades. Bring a fork lift!

Brian is probably contacting Dennis to cancel his CRPF membership right now!

Terry

Offline Owain

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Re: Setting up a home rotary phone network/switching system
« Reply #7 on: February 13, 2018, 04:42:46 PM »
Tier 1 - Basic voice connectionIf possible, it would be preferable to supply the necessary DC talking current from household power so that I’m not constantly consuming batteries.

The battery is usually on an open circuit when the phones are on-hook, so current is only used while speaking. This is how intercom phones were installed before mains power and rectifiers became widespread/affordable.

Tier 2 - Ringing
Another fairly base wish list item would be the ability to ring one phone from the other (even if this meant needing to press a separate doorbell-like “ring” button in order to do so). From my preliminary research, it seems the challenge would be generating the 90v/20Hz AC required to power the bell. I’ve encountered widely differing opinions on whether using straight 110v/60Hz current is or is not dangerous for either the phones or the users.

Using mains current to ring bells is unwise - phones are not built to the same insulation standards (particularly old ones) and you mention 'a child'. If you want to ring magneto bells use (a) a transformer (b) a transistorised ringing generator (can run from the talk battery) (c) a magneto or (d) replace with DC bells/buzzers.

A line simulator will provide talk battery and ringing voltage eg
http://www.classicrotaryphones.com/forum/index.php?topic=6141.0

Tier 3 - “Pseudo” switching
At the next level, it would be very nice to be able to dial Phone B from Phone A—even if it was as simple as dialing a single digit to establish a connection between the two.

You might be able to find a line simulator that supports this, but if you want an electromechanical one you basically have to start from scratch with obsolete and fairly uncommon parts. However there have been discussions here about building small exchanges and someone was updating the 10-line Telephone Exchange Using 22 Relays
http://www.classicrotaryphones.com/forum/index.php?topic=6218.0

Tier 4 - “Real” switching/expansionPerhaps the easiest and cleanest solution that would give me all wish list items at once would be to get some kind of a small, older PBX system (I’m assuming circa 1980s-’90s) and use it to connect rotary handsets.

It would be, and for practicality is what most people here probably use as their 'central' home exchange, with manual or electromechanical switches piggybacked on it.
« Last Edit: February 13, 2018, 06:11:09 PM by Owain »

Offline briantroutman

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Re: Setting up a home rotary phone network/switching system
« Reply #8 on: February 13, 2018, 04:49:01 PM »
Thanks for the responses. I know that whenever you join in with a group (online or in real life), there’s a certain amount of getting up-to-speed with the regulars, so I expect a bit of ribbing and in-jokes. In other words, don’t count me out of the forum just yet!

I have a small 1A1 system with a 9 station intercom... go to the TCI Library at www.telephonecollectors.info and start there...

Thanks for the suggestion and link. I’m reading the 1A1 system description at the TCI library right now. It seems like the 1A1 or 1A2 key systems might perform the functions I’m looking for, and I’ll follow up with questions I have after reading. But I can post a few that have occurred to me thus far...

It appears that the key systems’ equipment is designed to work together—including system-compatible phones. So instead of using a model 500 desk set, I would have to use something like a 565 with five line selector buttons and a hold button—is that correct? Or given the fact that I don’t need to access multiple lines or use a hold feature, is it possible to somehow adapt a single-line phone to work with a key system?

From the system description, it appears I’d be using what they refer to as the “Dial Selective Intercommunicating” feature to call between phones. I notice that in reference to an audible incoming call signal, it says: "The audible signal is operated once for a period of about 2 seconds.” So this is descriptive of the kind of ring I would hear?

Do any of the key systems produce dial tone? I can’t find a mention of it in the system description. It’s not necessarily a deal-breaker, but I wondered.

And finally, other than trying to get into old office buildings and find disused equipment in phone closets, do you have any suggestions of where I might look for key system equipment or if there are going rates for what they cost? I notice that there’s an annual phone collectors’ meet not far from me in Lancaster, PA (I’m in the Philadelphia area)—might this be a good place to look?




Edited to add: Thanks, Owain, for your detailed response—which just came through as I was typing this. I’m running out of time at the moment but will read thoroughly and respond as soon as I can.

Offline HarrySmith

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Re: Setting up a home rotary phone network/switching system
« Reply #9 on: February 13, 2018, 06:21:22 PM »
Welcome to the forum. Sorry about the jokes, just me & Terry being stupid or me being stupid and Terry just responding. You will find a lot of great people here with tons of knowledge & experience who love to help. A lot of us use a Panasonic PBX for our rotary phones. I am not an expert on any of the systems but I believe it will do what you want. They come up on eBay often. There is even a topic here where members post sightings of them for sale. We have a few switchers here that I am sure will chime in. Check out member weco355aman, he has several working systems you will not believe! Here is his website: http://www.strowgercentraloffice.com
Harry Smith
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Offline briantroutman

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Re: Setting up a home rotary phone network/switching system
« Reply #10 on: February 13, 2018, 07:32:57 PM »
Thanks, Owain! Lots of threads to look through and points to consider.

A line simulator will provide talk battery and ringing voltage eg
http://www.classicrotaryphones.com/forum/index.php?topic=6141.0

Thanks for the link—and the “lift receiver A to ring phone B” arrangement mentioned in the thread sounds interesting.

However there have been discussions here about building small exchanges and someone was updating the 10-line Telephone Exchange Using 22 Relays
http://www.classicrotaryphones.com/forum/index.php?topic=6218.0

Building it would involve quite a considerable learning curve, but the 10-line exchange seems to be exactly what I had in mind. Fortunately, my dad has a decent amount of electronics experience from his time working on radar units in the USAF in the ’60s, and this could possibly make a good father/son project.

Welcome to the forum. Sorry about the jokes...

That’s quite alright...I’m just glad to have a few helping hands as I try to sift through my options. Thanks for responding!

A lot of us use a Panasonic PBX for our rotary phones.

That might end up being the route I decide to take. Provided that my end goal would be to connect less than ten phones with the least possible amount of “intruding modernity”—such as the PBX repeating my rotary dialing digits as DTMF tones—do you (or anyone else) have any suggestions of units I should consider?

Admittedly, I can see how a modern PBX might open up some interesting possibilities—such as configuring longer numbers for the extensions or perhaps allowing me to create recorded call intercept messages. (I’m just guessing—I don’t know if these are features I should expect or not.)

Check out member weco355aman, he has several working systems you will not believe! Here is his website: http://www.strowgercentraloffice.com

Terrific photo (and equipment) collection! If he ever hosts a tour, sign me up!
« Last Edit: February 13, 2018, 07:36:16 PM by briantroutman »

Offline AE_Collector

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Re: Setting up a home rotary phone network/switching system
« Reply #11 on: February 13, 2018, 08:38:37 PM »
Welcome to the forum. Sorry about the jokes, just me & Terry being stupid ....

I do Stupid well!

Yes I think for someone just wanting to get a few phones working, the Panasonic systems make it easy and inexpensive.

Terry

Offline Brinybay

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Re: Setting up a home rotary phone network/switching system
« Reply #12 on: February 13, 2018, 09:20:02 PM »
Brian -

Ditto what Terry said.  Make it easy on yourself and look for a Panasonic PBX.  They can be had for not a lot of money.  It will do at least the first couple of tiers you mentioned.  You can either dial the extension or dial an outside line, no wiring or batteries needed, just a line cord with an RJ11.  Most you would have to do is string some line cords through your house if the extensions you want to dial are in other rooms.  If you want to get fancy, they can be programmed with a proprietary Easa-Phone.  https://www.ebay.com/itm/282830947858? 

I mostly use mine to test phones I've been working on.  If you want to drive your family nuts, you can hook up several phones and they ring in cascading order on incoming calls. 
https://www.youtube.com/watch?v=ILUvbF62yB4

Rigging magneto sets is another matter altogether.
« Last Edit: February 13, 2018, 09:29:48 PM by Brinybay »
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Offline Weco355aman

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Re: Setting up a home rotary phone network/switching system
« Reply #13 on: February 14, 2018, 01:25:55 AM »
Phil

Offline briantroutman

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Re: Setting up a home rotary phone network/switching system
« Reply #14 on: February 14, 2018, 12:19:02 PM »
Thanks for the additional responses, Terry and Brinybay! If nothing else, going the Panasonic PBX route would be a fairly easy and fast way to get started—and compact, too. And if I decide to do something more ambitious in the future (like build my own mechanical switch or buy a heavier piece of old mechanical switching equipment), I’d be able to keep whatever rotary phones I’d acquired...and perhaps even sell the PBX on to someone else if I no longer needed it.

If you want to get fancy, they can be programmed with a proprietary Easa-Phone.  https://www.ebay.com/itm/282830947858?

I wanted to ask because I’ve seen the “Easa-Phone” name used in various eBay ads and elsewhere to refer to either the PBX, the companion Panasonic phones, or the entire system. But I assume you’re referring to the companion phone—that the desk set can be used to program some of the PBX functions, right?

Based on the eBay link you provided as well as many other phone collector demonstration videos I’ve seen, it seems like the Panasonic model 308 PBX is a popular choice. Are there any things to watch out for—such as components that tend to go bad? Or model revisions that make some 308s better than others?

If you want to drive your family nuts, you can hook up several phones and they ring in cascading order on incoming calls. 
https://www.youtube.com/watch?v=ILUvbF62yB4

Funny! Yes, that would be a fun way to drive my wife, in particular, nuts.

Rigging magneto sets is another matter altogether.

You’re referring to older phones with a crank that was used to signal the central office, correct? I don’t anticipate that I’d be getting into equipment of that vintage, so I should be OK on that count. I had planned on using primarily 500-series type phones because I thought they’d offer the best overall combination of durability, availability, and price. But if I’m incorrect, by all means, set me straight.

Youtube video of my SXS.
http://www.youtube.com/watch?v=ivQ7b3dtIzI

Terrific video! I’m always fascinated by elements like the cam used in the interruptor to generate the cadences of ringing signals, busy signals, and reorder tones. It’s that interface between the mechanical and electrical worlds that intrigues me. Honestly, I think my ultimate (and perhaps impossible) goal would be to have my own step-by-step switch in the basement.