How can a couple of butt sets be set up for point to point comms?


This exercise is for grid down, local comms at a homestead or bugout location for a secure line from an LP/OP to the main house or between LP/OP's.  It's not intended for phone
calls from a telco box, although that could be a secondary use.  Will the POTS still work if power is out?  IIRC POTS used to be battery powered.

I have mil field phones and even several hundred feet of mil steel phone cable.  The cost of a mil field phone (plus shipping) is high, so I wanted to experiment with something else.
You could do the same with an old POTS telephone, but I figure the butt set will be more durable.  Butt sets are about $20 shipped on Ebay.  Field phones are $80+.

I'm sure there are local telco offices with boxes of old butt sets that could be had for nothing if you know the right person.

The new Fluke tone generator is $70.  Amazon has Chicom models for less than $20.  Ebay has used Klein and Fluke generators for around $30.  It looks like 2 are needed for
a point to point line.  Fifty to sixty dollars per phone, plus wire should have secure comms up to a mile away.

You just need a pair of wires.

How do you power it?

My butt set has a 9v battery, yours does not?

I have never tried to use a butt set on just a wire to form a talk circuit. (IE: Butt set - Wire - Butt set).  I have always had blow battery from the CO.  I believe the battery in the butt set is just for the speaker feature.  If you wish to make a talk circuit, you need some DC source to power it.  

The Fluke Pro3000 Tone Generator has a diagram on how to set this up with two tones and two butt sets.  The range is about a mile.

Tone
Page 4 of the manual

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One reason is it allows communication almost anywhere.

Find a house or better yet a commercial building and open the DMARC and keep testing till you get dial tone.

While phone systems are all digital these days a lot of those buildings still have 2 analog lines for the fire alarm system


A lot of fire alarms are either cell or IP these days but a surprising number are not.

Thank you for the replies.

This exercise is for grid down, local comms at a homestead or bugout location for a secure line from an LP/OP to the main house or between LP/OP's.  It's not intended for phone
calls from a telco box, although that could be a secondary use.  Will the POTS still work if power is out?  IIRC POTS used to be battery powered.

I have mil field phones and even several hundred feet of mil steel phone cable.  The cost of a mil field phone (plus shipping) is high, so I wanted to experiment with something else.
You could do the same with an old POTS telephone, but I figure the butt set will be more durable.  Butt sets are about $20 shipped on Ebay.  Field phones are $80+.

I'm sure there are local telco offices with boxes of old butt sets that could be had for nothing if you know the right person.

The new Fluke tone generator is $70.  Amazon has Chicom models for less than $20.  Ebay has used Klein and Fluke generators for around $30.  It looks like 2 are needed for
a point to point line.  Fifty to sixty dollars per phone, plus wire should have secure comms up to a mile away.

Watch some of his other videos. He has some cool stuff.

Not really grid down grade but in the spirt of OPs topic.

One thing to keep in mind is that telco's are dropping support for copper since maintaining them is no longer required by the FCC.   So I would expect to find fewer open and functioning POTS lines on unattended DMARC's.   I would also expect the condition of existing copper lines to degrade rather quickly.   Accidental damage will accumulate and in some cases they may intentionally damage it as they install new technologies.  

One more point to consider is that come technologies like T1.5 lines use significantly higher voltages than POTS lines but can be found on the same copper wires.   It may be unpleasant to stumble across one as you hunt for open POTS lines.   I haven't done it myself but I understand that it gets your attention.

there is very little Plain old telephone service anymore

+1

The old, twisted pairs are quicky becoming a thing of the past.

They are virtually gone in residential areas.

However in commercial businesses you will often still find 2 lines active because of older fire alarms that still use them. I’m in the business I see them several times a week still. Yes they are going away but there are still out there in abundance.

Yea things can get
spicy at a DMARC.

A good trick is to simply look at the tags and anything written on the cabling. It will tell you a LOT.

I used to live in a small lakeside mountain hamlet.  Half the old part of town was POTS copper lines.  The new construction was not.  When the power went out only the POTS stuff was operational.  The house I was in dated a century back and was on the old stuff.

Except he's trying to create his own system, not tag into existing.

There's an app called FreePBX that lets you build your own Private Branch Exchange (which is what companies have that allows each phone to "intercom" each other for free, without requiring an operator to connect the circuits).

You need a server to host it, and a way to connect all the phones into it.

The server could be just an old desktop PC.

Most people use AdTran routers to get the phone interface(s) routed into RJ45 Cat 6 cable going to the PBX server.

"Amphenol" cables are what they use/used to connect multiple POTS circuits into a "trunk".

I only know a little bit about this telco stuff because I inherited an old Avaya BCM450 PBX that I manage at work. That was my first experience with a PBX.

One of the telco companies we no longer utilize abandoned an old AdTran device at one of our satellite offices years ago, so I've been considering playing with it just to see if I can hookup 2 (or more) POTS phones and getting them to call each other. It's a little larger than a toaster, but I'll still need the "punch" block (like an old 66 block), Amphenol cable, and a PBX server. The AdTran and the server both require AC power, but they'll power all the POTS phones through the RJ11 interface.

None of this tech works with USGI field phones because they use completely different signaling once you're past the Vietnam-era devices.

I have two 1990s USGI field phones and it's easy to run 4-strand field wire to have them intercom each other. They just need local (48V?) DC power or 110/120V AC power to work (and only one phone needs to be powered). If you want to connect more than 2 then you need the impossible-to-find TriTac military switching equipment (which was mounted in a big truck as the smallest option).

In short, portable radios work much better unless you're trying to establish a large stationary FOB with a reliable power supply.

The 2 butt set (or 2 field phone) concept is cool, until you want to connect more than 2. Then you either need automated switching equipment (PBX) or an operator with manual switching equipment routing all the calls.

Buttsets require voltage to work. You get -48VDC battery and 90VAC to 105VAC ringing. Equipment is powered from the CO or nodes and our fiber and copper stays up during a power outage. Fiber ONTs are on battery at the customer’s prem and copper is powered remotely.

As far as just grabbing a pair and checking, that’s stupid. We shoot 380V down some pairs to power remote equipment and you’re 100% liable for any and all damage when you clip on the wrong pair.



The newer Fluke buttsets are cool because they have lots of neat features but they’re battery eaters. The battery is only for speaker and the tools in the buttset.

If you’re wanting to do this you really want sound powered phones.

http://www.soundpower.com/spcc/index.html

Thank you.  I guess my posts are confusing.

I have 2 tone generators and 2 buttsets.  I connected them per the diagram and all I get is tone on both phones.  I'll keep trying.

Toners won’t generate tone when set to continuity test, that’s what you need to have them set on.

I tried every combination of settings between the 2 tone generators and get nothing but tone.  Maybe I have some bad phones.

Did you end up getting the Fluke PRO3000 tone generators?  If so, they need to be in Continuity Mode (CONT).  If you picked up some other brand of toner they may not work this way.  

From the instructions linked above:

In-House Communications (Talk Battery)
Two PRO3000 toners can power two telephone test sets on a pair of dry wires (Figure 5). This lets two people communicate on up to 1 mile (1.6 km) or more of a dry wire pair.

To use the talk battery:
1 Connect the two toners in series by clipping the red lead of one of
the toners to the black lead of the other toner.

2 Connect one of the toner's free leads to one of the wires of the
pair you want to talk over.

3 Connect the other toner's free lead to one of the leads of your
test telephone.

4 Connect the test telephone's free lead to the other wire of the
pair you want to talk over.

5 Put the slide switch on both toners into the CONT position.

6 Have the person at the other end of the wire pair connect his test
telephone to the wire pair.

7 Put both test telephones in talk mode then begin your
conversation.

No.  I got Klein, thinking they all work the same.  

I guess they don't all work the same.

Do you have two butt sets?  If so clip your toner to the CONT setting, clip it on the pair, and then clip both test sets to that same pair. Try that and see if it works.

Going to Google-U on Klein tone generators, it looks like the Toner-Pro always sends tone.

I was able to set-up the talk circuit above today and it worked with two tones from the same manufacturer.  I couldn't get it to work by intermixing brands for some reason.  The butt sets needed to have batteries to operate along with the tones.

Two Fluke Pro3000 tones and two Fluke TS52Pro butt setts.  The CONT light is green illuminated when the circuit is complete.  Both butt sets are off hook and I was able to communicate between them.
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Two Aines MFG Corp tone generators (140b and 240)
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Both of these setups provided talk battery for the circuit and the butt sets were able to communicate with each other.  Now how long this will last, I don't know.  The battery life will decide.  Keep in mind, this is only for talking. You can't ring one butt set from the other.  It's the modern day can and string.

Carrying a butt-set is a great idea and I have one in each of our vehicles, along with some tools and a “can wrench”to access outdoor pedestals and demarc housings on homes & buildings.  That habit began back in the 1980’s when twisted copper pair  POTS was truly ubiquitous.  I’m guessing it’d be tougher to jump in on a FIOS fiber drop. 🤣

Just a thought on private phone “systems”.  I used to carry a device from Leviton Telecom called the “InfoTest”.
It was the size of a small multimeter and could generate up to 8 unique tones for wire / pair location and identification, audible and visual circuit testing (open / short / voltage) and a ton of other features.  Just one of the more obscure features was a “private troubleshooting network”,  it was mainly used by techs working in large buildings or in different buildings on the same campus.

The InfoTest unit was able to be connected in series with up to 10 butt sets or conventional phones.
The device generates ring voltage to the other phones whenever ANY of the phones is taken off-hook.
It also provides talk battery to power the actual voice comms over a single twisted pair.
I used it for that feature when doing a large structured cabling install in a high-rise with limited cell coverage.
2-way radios wouldn’t work either due to the hostile environment and tons of concrete and street encountered in the building.
(plus.. radios were much more $$)
I left a cheap butt set in each wiring closet connected to the first pair of wire that we identified and left it all in place for close to 3 months.
It was perfect.

I still have an Info Test unit in my tool bag.
I should probably toss it into my car tool bag.  It’s great as a tone generator and all purpose communication tester.

fun topic!

You honestly don't need either item.

As a nine year old, I built my first butt set out of a telephone, a jack, and a pair of alligator clips.

All those toners are doing is supplying +18vdc for your talk circuit. It doesn't have to be that voltage.

So, you could get a couple of 2500 desk sets, and I bet money a 12v gel cell out of a deer feeder or old alarm panel and pretty much build the same thing. It would be talk only though.

I'm not certain of a simple circuit to supply ring on pickup. I know they have ring generators on ebay all the time for like $30 bucks, and that would be a start.

ringdown. The telco guys call it ringdown.

This is a little complicated, but cheaper than most phone line emulators:

https://www.instructables.com/Hack-a-VOIP-Box-Into-a-Telephone-Intercom/