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and very rarely ever needs repairs, once you fix them." - Dan/Panther

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Newbie learning about old phones - djtownsend

Started by djtownsend, April 03, 2011, 06:10:32 PM

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Hello all.  I just joined this forum because I have an interest in old phones and would eventually like to restore old phones.  Before I restore phones, I have to know in detail how these phones work.  I have a 500 series wall phone and it obviously has a network unit in it.  I understand that some of the leads go to the ringer, some to the dial, etc.  What I would like to know is what is the overall functionality of this network unit is and what are all of the screws for?  I have a picture of it in my phone below and I see a link where I can attach the picture but I don't know what to place between the .  I tried attaching the picture and hope people can see it.  

If this question has already been asked, and I suspect it has, I appologize and could someone please direct me to that message thread?



Is it a Western Electric 554?

This is the wall version of the 500 (desk) series.

Try a search on the forum and you will find loads of info or wiring diagrams.

Should be a doddle to get working, even my 554 here in the UK was easy to get up and running.

And welcome to the friendliest forum on the net, and good luck with your collecting.


"now this should take five minutes, where's me screwdriver went now..?"


Dan, Inside the box are capacitors, coils, resistors, varistors, and nasty goop. Some of the screws are just tie points and don't connect to anything inside the box. Check out this site to learn more. They can explain it far better than I can. > <
There is a link to a schematic that will give you an idea of what is under the cover.
Welcome to the Forum.
Doug Pav


Thanks for the information everyone.  This phone works but I have VOIP and this phone will not work with that type of service.  I think I will have to install a pulse to tone converter for me to have it work at home.  I've ordered one but just want to learn about this phone as it will let me learn about other phones.

Wallphone, do you know the model number of this network box?  I went to the site you indicated in your post and I see a number of schematics including 4228, 425G, and 425K but I don't see an exact match to what I have in my phone.  I need to do some more searching but your explanation of what is in the box pretty much explains it all.  I really don't need to know what is in the box but just how to use the connections on it.

Again, thanks for your responses.  I really like this site and will learn a lot from other members.



I think I've identified it as a 425K Network.  It just takes some searching and with anything, you'll find your answer.



Dan, You didn't say what company made your phone but your network should be ink stamped on the side.
Go here to find the wiring diagrams. > <
Doug Pav



My phone is an ATT/WE phone.  I'll look on the side of the network box to see for sure. Thanks for the info.




Your phone's model number should be clearly marked on the bottom plate -- probably both on the inside and outside of the phone.

For some general ideas on how the 500-series models were marked, check here:

If it's easier for you, start at the top of the page:

While you're visiting the TCI Library (Doug's link, above), search for "501-135-100" to read the Bell System Practice covering networks like yours.

A good introduction to the workings of telephones can be found in the book described here:
Visit:         WE  500  Design_Line




Paul-f posted a link to a book by Ralph Meyer.  I consider Ralph Meyer's book to be a "must have" if wanting to learn about telephone circuits.  His book takes the electrical theory of phones from the basics up to the phones of the 70's and '80's which are the 500's and the touch-tone 2500's.

The 2500 and 500 family are a variation on the antisidetone theme that has been in existence since the 1930's  The network can of the model 500 family is the 425B and other 425 variations.  That network contains the induction coil and a few other parts.  It is built on the same circuitry of the model 302 and the earlier model 202.  The 500 also has a few extra components in the can that are used for varying the strength of the signal you hear based on the DC resistance between the phone and the central office.  These extra components make for a more enjoyable experience in using the telephone such as reduction of loud clicks heard in the receiver and a more level and constant volume to the user.  All that is explained in detail in Ralph's book.

I do not think it is practical or even possible to conduct a class on line in this forum for the learning of telephony, but by studying the things that are on line one can get a reasonable basis for the knowledge.  Another book that is available on line and free is the Army's "Fundamentals of Telephony" TM11-678 published March of 1953.  (pdf) You can find it on Collin Chamber's website at and click on Big Books in the side margin.  It is over 65 meg, so it is a large book, and cannot be posted here.  That book covers the phones widely in service in 1953, which is the 302 and others like it.

It also covers switchboards, analog switching and central offices, and long distance and repeater circuits.  It has a broader range of topics than Ralp's book, but the parts on telephony are very educational.

-Bill G


Thanks everyone for the information.  Everyone here is very helpful and I appreciate the info people publish here.


Greg G.

Welcome to the forum!  Unless you're already trained in electronics, don't worry too much about which screw does what.  I know diddly/squat about electronics, but it's usually a matter of moving a wire or two, and there's plenty of willing and able help in these parts.
The idea that a four-year degree is the only path to worthwhile knowledge is insane.
- Mike Row

The army book Bill Gerts recommends is must reading for anyone that wants to learn how a telephone functions. I got tired of trying to read my copy of the download version and found a hard copy on eBay - look under military - US - WW2.