Build an Intercom using two old Telephones

[@mgrifi3944]

I’m so Glad you mentioned kids thinking this is cool- this is why I was looking for videos like this. We have kids who are playing with old phones and I’m trying to see if I can hook something up

[@timotb1]

Need to be able to ring second phone by just picking up phone one. How?

[@jasoncreech4486]

I have wanted to do this for years. One in the house and one in the building.

[@escapetoparadise2226]

How to make ring???????

[@DonCharabin]

Can this work to be extended to five to ten phones? Just keep running the connection to another double-jack wall plate?

[@thechris2427]

Thank you my friend. This was exactly what I was looking for

[@bthemedia]

Nice work, just what I was looking for!

[@theungoliant9410]

How do you activate the ringer?

[@zell9058]

Exactly what i wanted for my kids tree house

[@-Stop-it]

Excellent! Just did this with a pair of cordless phones. I used a 0-500 ohm potentiometer for the resistor. Wonder how long the 9 volt will last and if I can substitute the right sized charger (from some other discarded electronic gadget).

[@NoSuffix]

Try to use a similar voltage DC power supply from any unused small electronics instead.

[@yannickcoeuff340]

I will definitely do that for my 2 sons ! Thx sir !

[@0033mer]

Have fun!

[@NT121784]

Anyone know what you'd have to do to make it ring?

[@clasicradiolover]

I was just wondering about a ring down circuit.

[@0033mer]

Yes .. it can be done. kzbin.info/www/bejne/sKi4hGSVfdhpppY

[@lucareno8467]

I would like to remove a doubt. What is resistance for?

[@douglasburum9794]

Without the resistor, the 9V battery would essentially be shorted through the phones, and would rapidly drain itself (and get rather hot in the process). The resistor establishes a constant, reasonable DC current through the phones (about 30 mA) that can be modulated by the two phones to communicate.

[@hypedupdemon]

With the phone jack face plate, would it be possible to use multiple and use it to switch between different users? Like a switchboard controlled with a selector switch/pot? How would you make the other phone ring?

[@rpruitt21]

How would you calculate what Ohm you would need for a setup of 300 yards Is there a formula where you plug in distance and give you ohms?

[@0033mer]

Put an Ammeter in series with the loop and adjust resistance to get 15 to 20 mA of loop current when both phones are off hook.

[@sierraseven3680]

Could you wire an LED light into the system, so that when one receiver is picked up, the light would alert the person on the other end?

[@0033mer]

Yes .. you can sense loop current and turn on a LED. Others use a buzzer. Check out this video. kzbin.info/www/bejne/aZ2YpJhmnKyAZ5o

[@ohayuhanna]

@@0033mer Thats a great answer and a great video you linked to. I just wanted to ask here just to be certain. Will using a bigger battery really fix the problem of carrying the voice signal over long distances? My friends had an intercom but you couldn't hear anything after 700m~half a mile, and in the video you linked to, he says using a bigger battery will fix that problem if you want a mile or so.

[@NortelGeek]

Nice Unity set!

[@TheKnackeredGolfist]

does it matter the watts of the resistor? I am going to connect 2 phones together in the same room to record character voices.

[@danfinnigan2489]

That is awesome!! Thx for the video!

[@0033mer]

You're welcome.

[@leonardotognetti5232]

Hi! great video. Is it possible to can share how you can build it? I'm not that practical but if I see it maybe I can do it!!!

[@NotCaily]

what if we want too be able to dial them. or is that not possible

[@ctvediting]

Um...how do you call out without a ringer? Or something else.

[@sauravmodak2365]

Can it ring?

[@masongovender9231]

How do you get it to ring?

[@doramilitiakatiemelody1875]

Nice video so i can make my own intercom for home if i wanted to ^_^

[@Michael_Kerstein]

Cool 😎 Got a couple rotary's now I know what to do with them

[@ChrisFredriksson]

Really cool project, just thought there would be some showing how it worked as well =) Does the other phone ring when you lift the first handset or do you just have to hope the other side is listening when you pickup the handset? =D

[@0033mer]

The phones will not ring. If you ran multi-conductor wire between the sets you could wire up a buzzer system.

[@Flapjackbatter]

Interesting. Does the one phone make a clicking sound if you rapidly make and brake the connection on the other? I mean rapidly tap the switch that the handset breaks when you hang up. I wish I had 2 old telephones to try it out.

[@0033mer]

Yes ... You can hear clicking in the earpiece if you tap the other phone's hook switch. The clicking would be caused by the voltage change in the line.

[@missouripatriot6926]

@@0033mer would it be oissbkie ti wire up 4 phones if more batterirs were added

[@Michael_Kerstein]

@@Flapjackbatter Morse code .. Glad I stopped by this video ! Lots of good ideas coming

[@BBMStudios_]

can i use a newer digital phone (like from 2017)

[@davidbilec3009]

Um how do you make it ring?

[@djpaulandre4214]

its that working for three intercom?

[@giacomosmiderle9717]

I' ve got only 2 wires l1 and l2 how do I konw is are those?

[@dandymcgee]

i was hoping for a demo, but good info nevertheless

[@Ray-chan-1c]

Would this work if one of the phones is a rotary?

[@0033mer]

Yes ... a rotary phone will also work.

[@GRAVESAUDIO]

I made this but am getting a loud feed back out of my speakers? any help would be great! Also i dind use a resistor is that the problem?

[@0033mer]

The resistor is needed to limit the current. Check that all your components are in series.

[@clasicradiolover]

Are you using them close together?

[@tomroach4701]

Hello My Name is Tom. Very nice presentation! Would it be possible to use a 9 volt battery ( or other if needed) with the resistor you mentioned along with 2 corded sets of mobile phone style ear buds with the microphone built in as the phone headsets?

[@0033mer]

No .. the circuit is designed to connect two telephone sets together which contain hybrid transformers. The current loop goes through both transformers which enable the phone sets to communicate in full duplex. You would need to simulate that with your setup.

[@pntiwari4937]

Good video

[@ADENCO-PC]

Not you getting 2 9 bat 18

[@tomroach4701]

Got it thanks

[@great_adventures_with_jonathan]

hi

[@giacomosmiderle9717]

I' ve got only 2 wires l1 and l2 how do I konw is are those?