Using Stomberg and Leich phones for intercom need help with wiring and battery

[Buddha72]

Hello,

I have a project where I want to have a wall crank phone in a 1920s speakeasy as an intercom to another room. I picked up this awesome flea market find of a Stromberg Carlson wood wall crank phone. It's small 3 bar and has the number SK1867I stamped on the back. I cannot find anything on the internet about it. I need this to talk to another phone but rather than convert it I thought I would just get another crank phone for it to talk to so I picked up a Leich 901b desk phone.

I have a couple of questions.
I actually have two Leich  901b's and have connected them and got them to ring back and forth then I added a 9v battery and was able to talk one way. So a general question about battery (power source) to use. How were these originally connected to power? I'm gathering that they are more hybrid local/common battery. Perhaps local to a building but common battery used to power all phones in a building or office. Of the four wires which was connected to battery.


The Stromberg Carlson looks to be totally complete. There was what looked to be a part from something else floating around inside. The wires didn't match any inside. I have search all over for a wiring diagram but I have not found one. There are clearly two terminals that a battery looks to connect to but I am very new to this and need some help understanding what kind of battery. I've read about people putting capacitors in instead of batteries? I didn't want to simply connect a 9v because I thought the magneto puts a charge to the battery but I may have misunderstood that.

Can anyone give some guidance on how I can connect these two to work together? It should be pretty straight forward if all the hardware is in working order. I just want to ask before hooking up any power.

Thank you,
Rob

[dsk]

Hi Rob! Welcome to the forum.   

The hand crank telephones is often called LB telephones. (Local Battery)
So each phone had their own battery, usually 3 Volts.  They used huge telephone batteries lasting for many ears, but the need of power when it is in use is small, and you will probably talk half an hour a day for several weeks with 2 AA batteries.

A small 9V battery for testing will probably not harm the transmitter (microphone) but for regular use you should be careful to put in more than 3-4.5 V. 

The best would be to connect the telephones 2 or all 3 together with a pair ow wires, preferably twisted, and put in a 3V source to each phone.  The polarity of the battery is usually not important.

dsk

[dsk]

LB telephones may need to be connected together and be off hook to test if the battery is wired correctly, with no connection the receiver may stay "dead" during the test, and you have no indication of, if it is wired correctly. 

dsk

[poplar1]

On the Leich 901, connect the Battery to red and yellow wires, and the other phone(s) to red and green. White wire is not used.

Or, if your cord has a black wire and no white, connect battery to red and black, and other phones to red and green. Yellow is not used.

The hand generator (magneto) is used only for ringing, not for talking or charging the battery.

[Jim Stettler]

The original dry cells for wood phones are #6 drycells. The voltage is only 1.5 volt. A pair of "D" cell batteries work fine for  talk battery.


Jim  S.

[Buddha72]

On my Leich 901b I have black, red, green, yellow?(brown), My other Leich doesn't have a model number on it but looks identical to the 901b so maybe its a c or other model. It has red, green, and what looks like two yellow or maybe aged yellow and white. I peel back the cord a little and the two wires still look like the same color either yellow or aged white. They are really a kind of brown. lol

I would like to hook one of these leich 901's to my Stromberg and Carlson Wood Wall phone. I can see two pretty obvious clips that I believe the battery would attach to. It does not have any colored wires coming out of it but it has three terminals. Two of which are connected to wires inside the box but one has nothing on it or even any solder pieces as to indicate its been used before. With only two terminals I am a little stumped on what to connect for the ringer and talk circuits from the leich phone. Based on the suggestion I'm guessing the red and green. I'll try some combination of what has been suggested.

I will have to figure out how to post images because I would love some more information on my Stromberg and its wiring and value.

Thanks for the guidance.
Rob

[Buddha72]

ok, I have ringers working to and from leich to leich. As well as leich to Stromberg and back. I am not having any luck with the talk circuits in either setup. I applied two d cells in series to the stromberg on its battery terminals. I connected another pair of batteries to the leich on the black and red wires then connected red and green to the wire terminals on the stromberg. no go. Is there a way to test handsets parts?

[stub]

Buddha72,
                 Here's diagram on the left in pic for your 901 as a local battery set.  Hope this helps.  stub