Communications for a tree house and …

[The Lazy L]

Spring I’m planning on building a tree house for the grandkids visits. Secondary use will be a deer stand and TEOTWAWKI.

I figure it would be cool to have wired communications from the tree house back to my communications shack. Military surplus was my first thought. Majority of the online venders are “Out of Stock” and the rest $$$$$$$. So what alternatives are there?

POTS, Plain Old Telephone Service. I’ve still have several analog phones from when I had a landline. Time for some YouTube searches. Found a simple solution.

I have a 12 VDC battery bank in my Comm Shack. I also have a telephone cable buried from the Comm Shack to a outbuilding that is within reason of the future tree house (buried the telephone cable for “just in case” when I ran electric to the out building). Spring I will bury a telephone cable from the out building to the tree house

Connect a fused 12 VDC Positive to the green wire on phone #1 jack (Comm Shack). Connect #1 phone jack red wire to a telephone wire that terminates at the tree house to Phone #2‘s jack red wire. Phone #2 jack green wire is connected to the telephone cable that terminates in the Comm Shack connect to the 12 VDC negative. Plug the POTS phones into the two jacks. Take one of the phones off hook and dial. If you hear the pulses or the DTMF tones in the handset the phones circuit is complete and will work as intercoms. Party at both ends can talk to each other.

But how do you know the other phone is calling? I could figure out how to to temporarily substitute the 12 VDC for for 120 VAC to ring a phone. But if I have a world record buck stepping into my sights in another second do I really want the wife to RING me that my MIL has unexpectedly stopped in for a visit?

No.

How about this? Take a lead from the fused 12 VDC Positive to the center terminal of a single pole double throw toggle switch. The two end terminals on the #1 SPDT switch connect to the telephone cable to the tree house and connect them to the end terminals on a second SPDT switch #2. The center terminal on #2 is connected to one of the leads on a 6 VDC LED light. The other LED on the light is connected to a 5th wire on the the telephone cable back to the Comm Shack and connect to the lead on #2 6 VDC LED light. The second lead from #2 LED is connected to the negative on the Comm Shack’s 12 VDC battery back. If I’ve got this figured out correctly the SPDT toggle switches are now wired as three-way switches. When one of the switches are turned on both LED’s light notifying the other end to pickup their handset. To turn the LEDs off either end toggles their switch.

This winter I’ll set this up on my work bench to confirm this will work.

 

[Maverickhawk]

For the grandkids! Sure....

 

[Bacpacker]

Sounds like a fun project over all.

 

[Dani]

I would LOVE if my Hunny undertook this same project and build a play house in our trees. We have plenty of oaks to choose from.

 

[Curmudgeon]

But how do you know the other phone is calling? I could figure out how to to temporarily substitute the 12 VDC for for 120 VAC to ring a phone

I would experiment, I don't 'think' you will need 120VAC to ring a phone just a few feet away.

Ma Bell used that high of a current because of the distance the signal had to travel. When phone lines are idle they are at 48v minimum usually.

 

[Caribou]

You could set up an A/B switch for ringer/light. Much light the ringer/vibrator on a cell phone.

I lived in a place that had a simple phone system that ran from the watchman house at a cannery to the hydroelectric plant. The phone never rang in all the years that our family was living there, but it was available if we had a need to use it.

The power went out, for the whole town, one Thanksgiving. Had we picked up the phone and rang the powerhouse they could have flipped one switch and we'd have had power.

 

[The Lazy L]

I would experiment, I don't 'think' you will need 120VAC to ring a phone just a few feet away....

96 VAC at 20 or 30 cycles I believe is common for the ringer. 120 VAC at 60 cycles is just easier for me.

 

[The Lazy L]

You could set up an A/B switch for ringer/light. Much light the ringer/vibrator on a cell phone.

I lived in a place that had a simple phone system that ran from the watchman house at a cannery to the hydroelectric plant. The phone never rang in all the years that our family was living there, but it was available if we had a need to use it.

The power went out, for the whole town, one Thanksgiving. Had we picked up the phone and rang the powerhouse they could have flipped one switch and we'd have had power.

A/B switch is a good idea...

 

[SheepDog]

I will have to look in my files. I am sure I have a way to set up two old phones as an intercom. They use a "Sonalert" buzzer as a ringer but it could be replaced by an LED. I think I ran it with 2 6 volt lantern batteries although it called for slightly more voltage and regulator of sorts. If I remember I will try to post it up.

 

[zoomzoom]

Sounds like it's a cool project to go wired but for me, I'd just go for a set of cordless phones. Pretty much all of them nowadays has an intercom system. Keep them in the house or wherever on their bases for charging then when you go outside, just grab one of the phones.

 

[The Lazy L]

Sounds like it's a cool project to go wired but for me, I'd just go for a set of cordless phones. Pretty much all of them nowadays has an intercom system. Keep them in the house or wherever on their bases for charging then when you go outside, just grab one of the phones.

Cordless phones quick and easy same as GRMS hand held radios but they both take batteries.

Co-worker left his handheld in charging mode 24x7x365. When it was needed during an emergency the batteries were toasted from over charging. My luck cordless phones would be dead when wanted/needed and just something else for me to maintain and to purchase. I've got still have POTS phones left over from when we still had a landline, 12 VDC battery that powered my radios and the majority of the communication cable already in place.

 

[zoomzoom]

Never had an issue with mine sitting in the cradle for extended periods. Heck, 2 of the 3 cordless phones on my desk are probably 15 years old, cradled most of their life and still work fine. Not sure if they're all the same but my phones are Uniden and Panasonic. My newer ones (the Panasonic) are probably 5 years old and can keep a charge off the cradle for at least a few days.