Magneto telephone to magneto telephone without a line?

[dsk]

Last Sunday I visited an old building in woods, historically the owner had his private line home at poles with insulators over something close to 11 kilometers (7 miles) Now 100 years later still not connected to the grid, and the phone line is gone, but they have power enough for internet vi cellphone network, so my idea is to help them getting up a magneto telephone to call "home".  The VOIP network is what I guess that will be the best. So far my first idea was to take a magneto telephone and switch the magneto connections so cranking will only ring the local bells, a capacitor to stop DC from going trough the ringer ...
Later I got an idea of a diode shorting the entire voice path until party answers, then you just have silence until you get the answer.  You crank the phone and hear the ringing (but actually thats also all that happens). Then you go off-hook and hear nothing (because of the diode). (the ATA is set up as a hotline) When party answers you may hear them and talk to them because the polarity has changed.  When they call your number the ringing is set to low frequency, eg 10 Hz and a 2 seconds ring, then silence.  Just answer and talk...  When finished you may ring off by cranking, or not (does not matter)  Any suggestions?

[dsk]

Here is a picture of the house, and I am glad it is not mine, or my job to keep it nice.  On the other hand, the owner is a good man for the house, and for the wally we live in.
https://nittedalsporten.no/2020/07/01/jaktslottet-rasjoen/

[countryman]

What a beautiful scenery, and what a nice idea to restore the old function with modern means. I'm sure it would work, the only thing that needs to be done basically ist to convert the phones to CB and make precautions to keep the magneto voltage out of the ATA.
Muting the line in the way you described would be the cherry on the cake, but requires well instructed users. One might think the line is dead if the other party does not answer immediately.

If google does not mislead me, it looks like the owner has the funds to keep up the house 
If he's also popular with his neighbours, even better!

[dsk]

Once it was one of the most wealthy families in the country, no reason to believe thy are poor yet , but not as rich as they were.  They are managing their areas as well as they are able to, and keeps a friendly attitude. You may come and put up your tent in the wilderness without asking, the only want you to clean up, and not leave garbage in the nature.

Last Sunday they opened the house for everyone to look at it, and told the story about the house. (at no cost)

It was at that time I got that Idea.  it is  far from the grid, and getting connecting to the power network will cost at-least
$ 500 000! That`s why they are offgrid.

[dsk]

I have not found a solution without changing the circuit in the magneto phone, but playing with the ATA made a setup.

You have to have a ringer with a capacitor, and a magneto generator that not sends AC out on the line.  When you go off hook you have to have a load to let the ATA undererstand that you have went off hook.

You crank the phone as in the old days, (and it does noting of importance), then you go off hook and it rings 2 sec in the other end. no dial tone, no ring back tone, just silence. 
When the other end goes off hook it works like it should.

2 phones 2 ATA's and you may play as it was a real magneto line. 

Here are my setup using callcentric as the exchange.  That makes it possible to call the Magneto phone directly from a "normal" phone.

[dsk]

The first common old magneto phone in Norway may have been https://www.classicrotaryphones.com/forum/index.php?topic=11725.0

The simplest modification of this may be this:   (needs a local battery)

[dsk]

 I do not understand this, but even when I have changed the dial tone, and it works with silent version... After some time, the dial tone is back, even when the parameter still say 10Hz.   

If you have a solution, please post it here. 

[5415551212]

Its a great idea and I have contemplated it, for wooden phones what I thought was needed is a purpose built 'open source' custom ATA PCB/hardware design that can handle the voltages and custom ATA software to bridge to SIP. 

[leejor]

Are you trying to "hotine" between two phones, or use an ATA, or connect to a VoIP provider?
I've done the former, and even created dialplans on each to simulate dialing the others number. It woks well as a phone demonstrator. Two port ATA to connect two phones.

You might consider replacing the phones "inners" (transmission unit, receiver and Mic) with modern equivalents where possible, as the originals were never intended to use 48 volts You may also want to utilize a hidden ringer so the phones original ringer is only decorative, and only rings with the crank.

[dsk]

Thank you for sharing your knowledge, and ideas. 
Here in Norway th phones made from 1918 and later did not ring their own bells when cranking. (A similar circuit as in the US field phone EE-8)

I have made the ATAs ring cadence to be 2 sec of ringing, and 28 sec of silence. The dial and ringback tone manipulation did not work out well, but polarity changes works. :-)

Now  am I just playing with a cb-phone, and a diode across the voice circuit.  When I go off hook the diode shorts the line, and I do not hear sounds.  When the party answers, it works.. Just tested for 2 days, but it woks.

This will in that case simulate a non dial CB phone on a CB line with a manual exchange.  The next may be to modify a local battery phone.

Here is the test phone, and the ATA does not understand pulse dialing.

[dsk]

Carefully step by step

The German wwii phone modified in CB use, works well.  A strap, and one wire with a diode.  (Does only work with a PTT handset)  The diagram shows a  solution with a diode in series with the battery, that makes it working without PTT, but the battery voltage has to be higher.

Looks like it work well with the PTT solution, and no handle on the generator.
The terminals marked with orange dots are the connections for battery and line.  The line will be polarity dependent, and the ata should change polarity when connection is etablished.