Batboard

I landed a new job caring for a mid-sized Avaya phone system. I have been doing circut inventory & found several sets of pairs labled SAC, police, fire, etc that start at the MPOE & enter the house witing (do not connect to the switch at all). There are no LEC circuit ID's, just the text lables.

The local LEC contact has no clue who owns the circuits, I don't want to tone them out, the facility people have no clue, and so far none of the PS folks have returned my call.

Other then remove the jumper at the MPOE & wait for the screaming to start, how the (NWS Word) does one get the attention of the LEC or the owners to ID the circuts?

Martin

I don't know about New Joisey, but up here, you could call the local telco and explain who you are and that you would like to know if it would be okay to remove them. They'd likely be able to tell you.

Alternately, you might want to have a telco tech come out on a 'line label' call. They'll send out a tech to figure out what you're dealing with and label them for you. Here, you'd be charged a small fee for the service.

Is there battery on the pairs?

Todd

I often find myself in similar situations. I generally elect not to muck with the unidentified circuits. What I've found in the past is that over the first couple of years their purpose often becomes known as service shops or techs ask for access to the telco entry demark, IDF, or actual equipment.

Follow the path of least resistance, just leave it alone for now. Mark them on your inventory as "unknown" and fill in the particulars when some failure or change requires work on the circuit.

What are they going into, from the MPOE? What cable? There are no open pairs on the cable you could tone on? If you do a tip/ring to ground test with a voltmeter, do you get a voltage?

As for now, I'm leaving them alone. A better description of what I'm dealing with:

AT the MPOE, after the protectors I have 1200 pairs from the LEC (on 110 blocks) Most are unused. I have several unknown 2 pair circuts that have jumpers directly to the house cabling field.

From there into a 300 pair riser. House pairs are numbered non-sequentially on this riser, so I have no clue what floor they drop off on.

BTW, All of the 1 pair circuts & trunks at MPOE have been ID's via the CO ANI readback. The T1's & PRI's I can ID by the sound (via inductive pickup - I don't know who the owner is, but have red-capped it.

Question: If it's a Tone Remote (or DC Remote), what can I look for sound / voltage wise ?

Martin

"...Question: If it's a Tone Remote (or DC Remote), what can I look for sound / voltage wise ? "
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Right there you have hit on the root problem we in the two-way business have been fighting for years.

What to look for? Unless you happen to be 'looking' [butt-in set, transmission test set] at the exact moment a transmission is taking place on the radio system - there is NOTHING to look for.

An idle two way line is a dry pair. It looks like any other vacant pair - so the telco installer who is trying to find a way to install service [and has poor facilities documentation] hooks on - hmmm, no dial tone, no battery - ahaaa - vacant pair, I'll take this one.

Now - if the telco made that installer take the resulting trouble call from the two-way customer - maybe they could close the loop and solve the problem.

Here's the answer for what you'll find on the circuits, when they're active:

DC: any of several current levels, 2.5mA, 6mA, 15mA, and + or - polarity.
(see: http://cpicomm.com/; look under DR10 Manual), and of course audio. The different levels & polarities do different functions at the radio end; PTT, Monitor, PTT on Freq1, or Freq 2, yadda, yadda. Depending on what is at the radio end to decode.

That's if it's a 2wire circuit; you'll get audio going to & from. If it's a 4wire circuit, you'll have the TX audio going on 1 pair, with the control currents, and then RX audio from the radio end, on the other pair.

If it's Tone Remote, you'll have the regular audio (BTW, often put in at each end about 0dBm or -10 dBm, depending on the whim of the installer.), and when the radio is given a command, it's in the form of:

120 mS. High Level Guard Tone (often called HLGT): 2175 Hz. @ +10dB from reference;

40mS Function Tone; (this tells the radio what to do; PTT on Freq1, change to Freq2, Monitor), at 0 dB reference, then

continuous Low Level Guard Tone, (called LLGT) @ 20 dB below the level of the Function Tone.

Function Tones are: 1950Hz (PTT on Freq 1), 2050Hz (Monitor), 1850Hz (PTT on Freq2), 1750 Hz, 1650Hz, etc. Very rare to see even 1850 Hz and below, in my experience.

Function Tone level should match your voice audio level; i.e. if you put in voice at -10dBm, your Function Tone will also be -10dBm, and your HLGT will be 0dBm, and your LLGT will be -30dBm.

Again, everything is swamped together on a 2wire circuit, but for 4Wire, TX & Control on one pair, RX audio on the other.

I suppose if you can scrounge up a couple Tone &/or DC Remotes, hang em across the lines, and start monitoring in HI-Z, you should hear something. Might even be able to feed the speaker/earpiece audio of a deskset into a recorder and gather your evidence of intelligent life that way. Really harsh would be to do it the outside telco tech's way & just A) open the circuit 'til somebody screams - bad form; or B) latch onto the circuits with said remotes & start generating "Radio Service Testing...." but that's pretty haphazard in my opinion. You may get a response, but like A, maybe not a pleasant one.

Ah, the excitement of no documentation!!! Long live tedium, when you could be doing other, more exciting things!

Enough to get you started?

Chuk G.

spareparts wrote:As for now, I'm leaving them alone. A better description of what I'm dealing with:
.................................

Question: If it's a Tone Remote (or DC Remote), what can I look for sound / voltage wise ?

Martin

Here's the answer for what you'll find on the circuits, when they're active:

DC: any of several current levels, 2.5mA, 6mA, 15mA, and + or - polarity.
(see: http://cpicomm.com/; look under DR10 Manual), and of course audio. The different levels & polarities do different functions at the radio end; PTT, Monitor, PTT on Freq1, or Freq 2, yadda, yadda. Depending on what is at the radio end to decode.

That's if it's a 2wire circuit; you'll get audio going to & from. If it's a 4wire circuit, you'll have the TX audio going on 1 pair, with the control currents, and then RX audio from the radio end, on the other pair.

If it's Tone Remote, you'll have the regular audio (BTW, often put in at each end about 0dBm or -10 dBm, depending on the whim of the installer.), and when the radio is given a command, it's in the form of:

120 mS. High Level Guard Tone (often called HLGT): 2175 Hz. @ +10dB from reference;

40mS Function Tone; (this tells the radio what to do; PTT on Freq1, change to Freq2, Monitor), at 0 dB reference, then

continuous Low Level Guard Tone, (called LLGT) @ 20 dB below the level of the Function Tone.

Function Tones are: 1950Hz (PTT on Freq 1), 2050Hz (Monitor), 1850Hz (PTT on Freq2), 1750 Hz, 1650Hz, etc. Very rare to see even 1850 Hz and below, in my experience.

Function Tone level should match your voice audio level; i.e. if you put in voice at -10dBm, your Function Tone will also be -10dBm, and your HLGT will be 0dBm, and your LLGT will be -30dBm.

Again, everything is swamped together on a 2wire circuit, but for 4Wire, TX & Control on one pair, RX audio on the other.

I suppose if you can scrounge up a couple Tone &/or DC Remotes, hang em across the lines, and start monitoring in HI-Z, you should hear something. Might even be able to feed the speaker/earpiece audio of a deskset into a recorder and gather your evidence of intelligent life that way. Really harsh would be to do it the outside telco tech's way & just A) open the circuit 'til somebody screams - bad form; or B) latch onto the circuits with said remotes & start generating "Radio Service Testing...." but that's pretty haphazard in my opinion. You may get a response, but like A, maybe not a pleasant one.

Ah, the excitement of no documentation!!! Long live tedium, when you could be doing other, more exciting things!

Enough to get you started?

Chuk G.

spareparts wrote:As for now, I'm leaving them alone. A better description of what I'm dealing with:
.................................

Question: If it's a Tone Remote (or DC Remote), what can I look for sound / voltage wise ?

Martin

Placing a 1004hz tone at about +3 db on the suspect pair will usually result in a response if the circuit is in use. This too is considered "bad form" in some circles....

mastr wrote:Placing a 1004hz tone at about +3 db on the suspect pair will usually result in a response if the circuit is in use. This too is considered "bad form" in some circles....

Yea, just leave the toner on the line and start timing how long it takes for radio service to arrive. Then ask the tech who called them.

Does your company take up the whole building or are there other tenants?

Wait, lets try this. Do you have a really tall building? Are there antennas on the roof? I would venture a guess that they are for one of two things:

1. A receiver and/or transmitter on the roof because your building has a really good spot and probably charges the municipality a lease for the space.

2. A recevier inside the building for fireground portable coverage.

KG6EAQ wrote:Does your company take up the whole building or are there other tenants?

Bob,
One floor is leased, the rest is used by the company. We lease space up top & have a bunch of PS stuff up there as well.

nmfire10 wrote: Wait, lets try this. Do you have a really tall building? Are there antennas on the roof? I would venture a guess that they are for one of two things:

1. A receiver and/or transmitter on the roof because your building has a really good spot and probably charges the municipality a lease for the space.

Matt,
Was up in the penthouse today - It's lousy with RF equipment. Looks like I will be managing some of it as well as the PBX.

We did RFQ's on running a seperate conduit & 50 pair cable from the MPOE in the basement to the penthouse. Will be running a second empty conduit for fiber.

The reason I was up there? Well, I was working on a broken phone & in walks the Radio guy from the FD. He had a circuit issue. One 2 pair circut down! 6 More to go!

Martin

So, you didn't quiz him about any other circuits he might know about? Get his phone number? (office & cell) Give him yours? Buy him a coffee or soda? (sorry, to some on the board: "pop") Offer to look out special for his circuits if he's in a pinch? Give him your home phone number? Ask him if he's ever had any trouble getting access, and if he ever does, call you right away?

Get the picture?

Chuk

spareparts wrote:
Was up in the penthouse today - It's lousy with RF equipment. Looks like I will be managing some of it as well as the PBX.

We did RFQ's on running a seperate conduit & 50 pair cable from the MPOE in the basement to the penthouse. Will be running a second empty conduit for fiber.

The reason I was up there? Well, I was working on a broken phone & in walks the Radio guy from the FD. He had a circuit issue. One 2 pair circut down! 6 More to go!

Martin

kb4mdz wrote:So, you didn't quiz him about any other circuits he might know about? Get his phone number? (office & cell) Give him yours? Buy him a coffee or soda? (sorry, to some on the board: "pop") Offer to look out special for his circuits if he's in a pinch? Give him your home phone number? Ask him if he's ever had any trouble getting access, and if he ever does, call you right away?

Heck Yes! - We walked the building redcapping his circuts at the IDF's & the block in the penthouse as an interim fix. (was concerned that the tennant telco contractor had did the damage) Tagged the FD circuits at the MPOE & put his circut ID's in the spreadsheet.

Martin

Well, the first 30 days are over - I covered 95% of the building looking for mystery equipment. Found one area using a 1A2 key system behind the PBX . Ripped that out right down to the station cables & rewired the office for voice & data.

Included in my AOR is a 3 year old Zetron 640 DAPT-XTRA paging terminal hooked up to a GM300. The poor GM300 has been bit banged & warped to work on a VHF splinter channel, with an external pot for level. It's clearly not up to the job by the number of muffin fans on the heatsink, and the 150 watt TPL amp it's tied to.

One suggestion for a replacement was the PTX-150 by Sonik http://www.sonik.com/prods_ptx-150.shtml If there's a better product in the sub $2000.00 range I'm open to suggestions.

I do not belive you can run that kind of RF power on a splinter channel. There must be a license, AUTHORIZATION is what the FCC calls them, somewhere that would have the tech. specs. ie: TX power out put an antenna constraints.

The Zetron would be a good choice to keep, they have support....


Oh, don't forget 'station ID'.

I ran the frequency we pulled from the code plug on the FCC website (TX frequency - state/county) It's not there! Monday AM the paper trail starts as no one seems to know who was responsible for renewing the license.

Went into work this afternoon & physically removed the GM300 and fuse from the DC supply.

Martin