atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telecom Service & Providers Pair gain trouble??

So this is an extension of a topic I started in a different place. I have replaced the system and sets at this office space three times now and I am kind of over it.

Details: low volume on lines from time to time (butt set too). The customer complains of "the batteries going dead". Translation, while on a call the volume all of the sudden drops off. Other times its bad from the start.

So I run some tests with my meter and the lines removed from the system. I then try a different meter just to see if I am getting the same readings and I do. Just to satisfy the possibility of my readings not being accurate . I call in a tech from the provider. I ask him to test the lines and I give him a little chart for documentation. His response to me "those tests are only good for dedicated lines".

OK so now I am thinking they are using either a multiplier or a channel bank in the closets for this building.

His test results follow.

MLT/Tone

SW:DMs100
OE: AA38-0-12-22

Ver: OT
Summary : TEST OK
TONE RINGER DETECTED
KOHMS 3500.0
DC SIGNATURE VOLTS..........AC SIGNATURE KOHMS
T-R 0.......................32.0
T-G 0.......................1394.0
R-G 0.......................1477.0

Balance capacitive 99
longitudinal decibels 65

On hook 30ma
Off hook 52vdc

Anyway now I am out of ideas and ready to pull my hair out.

1. Longitudinal Imbalance!
2. At what level does a milliwatt tone arrive at the nid?
3. Line voltage too hot!(Some sort of channel bank, which would square with your suspicions?) 4. Find the channel bank/pair gain device and temporarily put a UPS on it!

If they are truely on a carrier of some kind the only test that mean anything are the current and voltage. I do know different carriers give different results.

There should be no on hook current.
Off hook voltage should be down around 10 VDC

I would req they swap the line card out in that pair gain unit.

Ummm, I’m really confused on that comment "those tests are only good for dedicated lines" ... What did he think he was testing? :shrug:

Right there in the top of the test results it shows the OE (aka LEN... errrr now acronym free.. line side port off the switch) “SW:DMs100, OE: AA38-0-12-22

I don’t know if there’s enough info here to determine for sure but I’m thinking, no... There’s no local pair gain for this one based of the switch type of DMS-100 and the format of the OE designation.

Not enough here to know for sure but I’m going with the bad (imbalanced) pair as the culprit. Volume is rolling off as capacitance is building up over the duration of a call. Or just starts off bad from the start. Any reports from the customer on the symptoms varying depending on if it’s wet out or not?

I saw the LEN but didn't know that meant it was copper. If it's copper why the weird loop current and voltage readings? Unless the on/off hooks are backwards.

Sorry for the delay. Having to deal with other issues here in wet south Texas.

I thought the same thing when I saw the switch type. But his comment makes no sense to me.

He took no other test and that is why I am all jack up about this. Why an on hook ma test then an off hook VDC. The two lines that I did not add from his printed page are. "termination code: single party" and the date.

Sorry Lightning but I can not access the mpoe without bell present and I am having trouble getting them to commit to a date for me. As for the wet or dry thought. It is happening in all types of weather.

The Milliwatt test I was not present for and if he did the test I would assume he would have told me. The carrier techs here do not do a milliwatt anymore. They do a stress test only. My voltage tests were the exact same for all lines. On hook vdc 23, off hook vdc 50, loop current 26ma, ring current 85vac, all other vac 0

I agree that it looks to be direct because of the DMS and OE. But if that were the case why state the dedicated line comment?

So then a new question that I need to ask them is what is the loop lenght. While I let them know I would like a new meet date (again)

I'm no expert but from what i see ,the tech has to do:: Loop Current/Circuit Loss, Test at the customers NID.It could be trouble with Loop extender VF repeater, Loading irregularity, Bridged Tap connected to the line. Hope that helps .

On hook vdc 23, off hook vdc 50

That's GOT to be reversed - ON hook, idle, 50vdc
OFF hook, in use, 23vdc

ring current 85vac
That would be ring VOLTAGE, which should be superimposed on the 50vdc on hook voltage (so if you were to look at it with an oscilliscope, you would see it going from -35 to +135 peak to peak)

Nope its not reversed, I wish it were. That is the reason I called in a ticket. As for the ring current your right TTT.

I am going to go in on wednesday a take the readings again. But like I said, I used two meters and they both come back the same. Maybe I am loosing my mind but that is doubtful. Then I thought OK the system is causing this wierd voltage thing, so I removed the system from the mix and connected straight to the lines.