Partner power pair/clocking tone

[hondacrusher]

Installed a Partner ACS Rel 7 the other day. Client is complaining of the "clocking tone" or power pair of partner phone bleeding over on their conversations. I have heard this sound on all partners. I'm so used to it that to me it is just normal. If you turn the volume down on the handset it does go away. If the volume is turned up over a 1/4 to 1/3 of the way up then you can hear this noise.

Most of the phones in this building are being ran on "quad" wire (RED GREEN BLACK YELLOW) no more than 65' from the control unit.

Just curious if anyone knows what I am talking about and has a fix for this. Previous system was a 308 AT&T Spirit. Only one person is complaining of this problem. All other employees are happy with their new phone.

Ideas?

 

[TouchToneTommy]

Twisted pair wiring will eliminate the problem. Take the phone to the control unit and test there.

 

[dagwoodsystems]

Agree with TouchToneTommy.

If you replace your cabling with something more modern, I would also recommend not splitting the pairs. It's not a horrible practice--I do it all the time--but I wouldn't if your customer is unhappy with the audio quality.

The problem you are talking about is called "alien crosstalk", and you can introduce it in twisted pair as well by trying to drive multiple phones down a single cable.

 

[TouchToneTommy]

Dag, I'd really have to disagree with crosstalk on multiple phones in the same cable - as long as there are no split pairs, the twists will cancel out the crosstalk. Ever run a bunch of stations through a 25-pair? No problem there! Can't imagine running multiple 4-pair cables to feed a sub-terminal.

 

[skip555]

I just did a install in a machine shop , everything was termiated out in the shop hot dirty enviorment

we mounted a 66 block in the shop ran a 25 pair to a inside closet mounting the equip there drivng dozen phones .. no issues at all

we regualalry feed 2,3, 4 phones off a single 4 pair .

Honda crusher , you should have replaced the quad wire when you found it ( I hope you didnt run it )

that stuff is only good for a single line

 

[aarenot]

quad cable is sub standard, replace it. charge time and materials for it, tell them you tried it to save them the money, but it didn't work.

 

[hondacrusher]

I didn't pull the quad wire, it was installed by our company back in the 80's along with the Spirit system which was still running strong.

I have heard this sound on cat 5 wire but am willing to try new cable. Let you know what I find out...

 

[skip555]

if you have heard it on cat 5 , why not pull cat 3 ?

 

[dagwoodsystems]

TouchToneTommy is correct in that the twisting of like pairs (as in a CAT5e cable) has a noise cancelling effect. He is also dead right about split pairs.

I can't imagine running individual cables to a sub-terminal either, but this user sounded kinda picky. My suggestion is a bit overkill, but I just wanna help this guy close up his job.

I HAVE experienced the sound he describes on two occasions. In both cases, the horizontal cable run was both split and long. I'm not referring to the 25-pair feeders and such, but rather the blu/org on a single CAT3 or CAT5 out to one jack and grn/brn to the other (same outlet/drop).

In both cases, the cable runs were approaching 1000 ft in length, which is why alien crosstalk began to creep up on me. The longer these pairs run parallel, the greater the chances of bleed. This noise may also have been due to tightly bundled cable groups, snag loops or hard bends in the run.

This effect happens in EVERY twisted pair cable to some degree, but is really a problem for the Gigabit ethernet world. These types of complaints are a true rarity in the voice world.