News:

"The phone is a remarkably complex, simple device,
and very rarely ever needs repairs, once you fix them." - Dan/Panther

Main Menu

L-659-B2 Self contained Booth Telephone Conversion to CB

Started by TelePlay, January 19, 2020, 11:17:50 AM

Previous topic - Next topic

TelePlay

This railroad phone sat on the floor of an antique store for more than a year. The magneto crank was broken and they wanted $40 but ended up letting it go for $30. All of these "as purchased" images show the phone's condition with only settled dust having to be removed. The only corrosion was a bit in the battery box at the base of the batteries.







The magneto handle was broken off but turning it made the ringer work. When I opened it up on my bench, I found a very clean and almost corrosion free railroad phone from the early 60's.

The upper box is an AE Type 60 LB phone with ringer found in AE catalogs under part number L-658-B2.



The lower battery box has the same back plate as the upper with only the doors being different in that the top box door had a dial blank and the bottom box door was solid.

When both boxes are mounted on a wood backboard, the assembly becomes an L-659-B2 or as the catalog calls it, a "Self Contained Booth Telephone for use in wayside booths." These would be phones installed alongside railroad tracks in places where a train would stop and call in.



https://www.telephonecollectors.info/index.php/browse/document-repository/catalogs-manuals/automatic-electric/ae-catalogs/12521-ae-automatic-electric-station-equipment-catalog-4055-n-nov62-ocr-r-tci/file

When I took the lower battery box off to check the wiring, I found a NOS crank stuck under it, a nice surprise worth about what I paid for the phone.

The circuit diagram inside the upper box was in great condition as well.




( Note: click on attached images below to enlarge them for detailed viewing )

TelePlay

Had an extra, black cased AE Type 21 dial that was recently serviced (completely disassembled for cleaning) so mounted that on the upper box door. Cut the pulse switch into the L1/L2 line circuit and connected the shunt switch  into the talk circuit to remove the receiver, the talk circuit, so that no dialing pops would be heard when dialing out.

The bottom box had the same 3 raised ringer mounts as the top box so I decided to install a second ringer for use with a POTS line. I isolated the magneto ringer circuit from the POTS circuit and installed a C4A ringer in the lower box.

To do that, I had to create a ringer mounting plate that fit the box ringer mounts and accommodated the C4A ringer. The plate was cut out of a thicker gauge, un-coated and cheap 12" square steel baking pan. Any substantial metal plate could be used. This mounting plate was cut out with a saber saw and the edges cleaned up with a file - I do not have a metal shop, access to a metal shop or a work shop with anything other than hand tools and basic power equipment (hand drill, saber saw, etc).



I put grommets in the metal box holes to keep the mounting plate and C4A ringer separate from the metal box. Rather than paint the mounting plate, I covered it with a layer of black gaffers tape, a thick cloth tape that won't deteriorate and being thick cloth helped deaden any vibrations from the ringer. I used a 0.47 uF cap on the terminal strip to wire in the C4A as it would be in a WE 500.



By completely isolating the magneto ringer circuit (magneto and ringer) from the POTS talk circuit, I am able to ring the upper ringer and an extension ringer on my desk some 15 feet away to demonstrate how a magneto was used back in the day without sending the magneto ringing voltage into the POTS circuit.

As it is now mounted on the wall, this railroad phone is now both a POTS rotary dial phone connected to my Panasonic 616, the magneto ringer circuit connected to the upper box original ringer and an extension ringer and the enclosed C4A adjustable volume ringer in the lower box, the ring volume can be set to "the just right" level.



This is the very first ever LB magneto phone I ever worked on and everything that was done to convert the telephone for use with a POTS line is completely reversible (the battery retaining hardware is mounted to the battery box just below the ringer gongs).

It is now a fully functioning POTS rotary dial telephone with a separate magneto and ringer for demonstration purposes. The C4A ringer in this battery box provides a very nice sounding ring, better than heard when in a 500 base. The brass screen sound vent at the bottom of the ringer box allows the sound waves from the gongs right above it to escape containment.

Nothing was done to the phones exteriors other than going over the paint with one coat of Novus 2 and buffing with an cotton bonnet on an orbital buffer.

( Note: click on attached images below to enlarge them for detailed viewing )

dsk

Great job, and genius idea with that remote phone for demonstration.

Here is how I guess how I would solved the circuitry as you describe your needs.
The blue resistor could need another value depending on your line, ideal solution would be resistor and varistor as used across the line in e.g. Western Electric 500.  This solution lets the remote test telephone listen in and talk on your line when you are off hook.


Please sketch up how you solved the circuitry.


dsk

TelePlay

Quote from: dsk on January 19, 2020, 01:26:15 PM
Please sketch up how you solved the circuitry.

This modified circuit completely separates the magneto and original ringer from the talk L1/L2 circuit to prevent any chance of sending magneto voltage into the POTS line.

The terminal board in the lower box was wired to send the magneto voltage to an external ringer if present, and Terminals 3 & 4 (which went to the batteries) were used to connect the POTS line to the phone.

Then, remaining talk circuit was upgraded by adding an AE Type 21 dial, a WE C4A ringer and a 0.47 uF 250 V ring capacitor (for the C4A ringer) to convert this once LB phone to a typical POTS rotary dial phone with a working magneto.

This was my first attempt at doing something like this and it worked on first try so it really can't be that hard for anyone new to telephones to read an existing LB diagram, compare it to any AE Type 21 diagram and figure out what connections have to be made or changed to create the new POTS circuity in the LB phone.

dsk

Thank you! It is always something to learn by looking at how others solves it.

dsk