atcomsystems.ca/forum Forums Telephone Services Cabling Telephones Systems Wiring Are return losses and propagation delays applicable for telephone cables?

I got the question from my client to do return loss and propagation delay test on telephone cable they are purchasing. But manufacturing vendor saying these tests are not applicable on the telephone cable. But i cannot able to justify why these tests are not applicable on the telephone cables. I searched on the internet found nothing regarding this.

So, My question is why these tests are not applicable for telephone cable? is there any standard stating that?

Thanks.

My question would be why these test are needed? What are they running on it? Return loss and envelope delay were test run years ago on 4 wire private line circuits, not much call for it today that I know of. There are delay and other test run on fiber optics but that another world. I guess there's some in the IT world that believe return loss is still relevant, but if you certify a cable I don't see where checking loss and delay would be of any added benefit. I'm old school so I could be all wet.

When I see the words "telephone cable" I think UTP/ScTP and the only tester needed is a Wire Map Tester for quick basic tests.

When I see the words "Return Loss" I think Data cables and Certification testers for each category: NEXT, Delay, Attenuation to crosstalk ratio (ACR), Return loss, Delay skew,

When I see "Envelope Delay" (The terms envelope delay and group delay are generally used interchangeably) I think Audio System Measurements: Frequency Response (FR), Total Harmonic Distortion (THD), Output Power, Intermodulation Distortion (IMD), Noise, Crosstalk, Common-mode Rejection Ratio (CMRR), Dynamic range and Signal-to-Noise Ratio (SNR), Phase Distortion, Group Delay and Phase Delay, Transient Response, and Damping Factor.

I believe that your customer is just blowing "Buzz Words" around without knowing what it means, probably calls a 8P8C Modular plug an RJ-45 and a curly handset cord an RJ-9.

POSSIBLY your customer wants the "telephone wires" run through a certified tester. If it's Category 3 then test the wires as Category 3 and meets the parameters as set out by ANSI-TIA-EIA 568B page 57.


Remember if you are using a Fluke DTX series tester that Calibration and Service ends June 30, 2018

At GTE we did transmission and loss tests on the 2 & 4 Wire E&M Trunks on our private networks. On fiber we did the standard end to end tests with OTDRS. On T-1s and T-3s we did Bert Tests.

On LANs we tested and certified all cables to their particular standards: whether they be CAT3, CAT5E, CAT6 or whatever.

You cannot test a CAT3 telephone cable to Cat 5 standards, it'll fail immediately.

If we had a customer who wanted to install CAT6 cable and use it for telephones then we would certify it for CAT6. It would work for whatever he wanted it for. Overkill? Sure! But maybe he was future proofing.

Listen to JustBill and Professor Shadow - they're steering you straight.

Someplace in the dreaded Basement I may still have a GTE manual on trunk testing. If your guy won't settle for certifying then let me know and I'll see if I can find it. It's not applicable and he won't like the associated costs, but what the heck.

Sam