OSP Expert: Don McCarty

Those Special Cables


Troubleshooting low count cables and drops with today’s test equipment — I received an email from a field technician about a problem he was having with the fault location features of his multi-function test set when using the RFL, Open Meter, and TDR functions. He stated that the measurements were fairly accurate when using the manufacturer’s settings on cables that were 25-pair cables and larger. When measuring the distance to a fault using the manufacturers settings on small count cables such as a 6-pair cable, the measurements were inaccurate. Field technicians use many types of test equipment or multi-function test…

The Bane of the Unnecessary Truck Roll


I received this email from a retired field technician who is also a POTS and bandwidth customer of a large RBOC that he worked for. Donald, I’ve been reading your column for what seems to be 20 years. Always good stuff.  I was formerly an outside plant field technician, facility technician, and testing technician for a large RBOC. After an injury from a fall from a telephone pole that ended my career as a field technician, this led me to working at a rather prestigious space facility that has no aerial plant. My stint there lasted 14 years working and providing technical…

Fault Locating the Copper Infrastructure for Bandwidth With the Advent of IoT


The ongoing expectation of extended, reliable and quality bandwidth has always been a maintenance challenge for field technicians and that challenge has increased exponentially with the addition of IoT services. While fiber-to-thehome is the ideal solution for delivering bandwidth, for now, many residential customers depend on copper as the final step in supplying high-end services including IoT. Field technicians get dispatched on a myriad of problems to restore service, especially on bandwidth circuits that are fiber-to-the-node (FTTN). They are responsible for the cable pair, the drop, inside station wire if applicable, Wi-Fi, modems and other end user equipment. In the…

Bandwidth Demand


I received an email from Todd who is the Plant Operations Manager of a fine independent Telco. Don, We are replacing copper with fiber but can’t do it fast enough to keep up with customer demand, with the growth of the IoT the demand for speed is now!!! We have started to bond copper to get additional speed to these customers but we have some concerns. 1. We understand we need to keep our cable fill ratio to 50% or less — is this correct? (Can we increase this when bonding?) 2. When bonding, are there specific pairs we need…

The unknowns that make fault locating in sections of buried telephone plant difficult.


Most bad sections of buried copper plant are a slam dunk to fix, especially when the well-equipped and well-trained technicians are given time to find and repair the root cause of section failure. These buried sections are usually in the distribution plant, and they are usually 25-pair or 50-pair PIC cables. They have failed because of sheath damage, splice or encapsulation failure. It is usually fresh trouble if there are no prior complaints from the customer. First, when trouble-shooting a bad cable pair, the skilled technician using a multifunction test set that includes a resistance fault locator (RFL), an open…

Electric Fence Interference


I received a question from a field technician about electric fence interference. He shared that he had a case of trouble that included noise on the telephone circuit emanating from an electric fence in the area. He said that the line is free of DC type faults. He was wondering if it could be a grounding issue? In some 50+ years in the telephone business, I have dealt with the effect of electric fences on voice grade circuits, bandwidth circuits, and even rarely, circuits where the customer is fiber fed. Once the cause of disrupted service is proven to be…

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