The Loop Current Attenuator (ITC-4001) reduces
potentially damaging loop current to an acceptable level without
sacrificing the voice or data quality of a circuit.
The Attenuator is a very economical solution for protection of
expensive terminal equipment!
The Only Network Balanced Loop Current Attenuator, ITC-4001 Just Got
Now with 2 Female Modular Jacks AND Terminal Wires. Easy
for Punch-downs or Screw Terminals!
Excessive Loop Current is a Growing Problem!
Too Much Loop Current may cause those "phantom"
problems such as:
Combine electronic exchange or PABX offices, with electronic
terminals and the result is often:
Burned out key & PABX circuit packs
Damaged networks in Modems, Fax Machines,
Electronic Telephones, Personal Computers, ...or any electronic
Coin Telephone Networks can be "Cooked" by High
Use the ITC-3004-Kit (Loop Current Test Set)
to easily identify loop current problems.
Learn more about the Loop Current Issue...
With the installation of new central offices, miles
of fiber cable and repeaters, loop current is becoming a frequent
customer problem. (The optimum range for loop current is 23 to 35
milliamps - MA.)
We are finding abnormal loop current in a wide variety of
situations. Here are some examples:
One of the leading
suppliers of electronic Key telephone systems migrated their
trunk circuit packs into a new technology. To everyone's
surprise, trunk packs in several exchanges experienced only 50%
service life. The mystery was discovered to be excessive loop
current (over 60 MA).
An interconnect and
service company in North Central New York had one particular
line of key systems that gave them trouble for months. It was an
electronic type A2 key system that was plagued with short lived
central office circuit packs and erratic sound. Excessive loop
current was found to be the problem.
In a suburb of a large
southern city, a large number of electronic Key /PABX systems
and other terminal equipment were experiencing "phantom"
troubles, such as cutoffs, modem failures and circuit pack burn
up, etc. The problem was due to an excessive increase in loop
current after the local telephone company cut-in a new fiber
optic feeder cable.
An alternate common
carrier utilizing a bank of over 80 dialers for automatic" call
forwarding" was plagued by "mystery" failures in dialer
software. Dialers would "lock- up" and simply not function.
Never all at once, but one time or another and almost weekly.
The problem was central office trunks delivering from 50 to 69
MA (within FCC guidelines
manufacturer said their dialer networks were protected to 70 MA.
When the loop current was reduced within the 25 to 35 MA range,
the "mystery" disappeared.
personnel have experienced intermittent failures in the
electronics of their "smart sets." Often this is the result of
excessive loop current. Too much loop current can "cook" a
telephones electronics and cause immediate failure or at a
minimum shorten component life by constant exposure to higher
than necessary loop current. The Loop Current Attenuator will
protect and dramatically increase the life of the payphone
telephones are not immune from such problems. Excessive loop
current can affect transmission causing such things as howling
on the line, interference with volume controls, hearing aid
A large southwestern
airline discovered that loop current was the cause of on-going
trunk problems. The airline repeatedly attempted to get the
telephone company and PBX manufacturer to resolve the problem.
Finally their own in-house technicians attenuated the hot CO
trunks. The Telco and manufacturer never did get together.
A business in
Arlington, Virginia served by a mid-sized electronic PBX
experienced frequent cases of "can't send" on fax machines
behind the switch. The "switch" lines were measured and high
loop current was determined to be the culprit. The ITC-4001
solved the problem.
Another firm in the
same city was losing electronic features on stations with long
or off- premises cable runs. The problem in this case was
inadequate loop current.
In North Carolina a
business was experiencing a loud intermittent squeal on one of
its Watts lines. Four line cards and 65 maintenance hours were
invested before discovering fluctuating loop current ranging
from 36 to 52 milliamps.
A marginal loop
current of 19-20 milliamps was responsible for a long distance
switch ! not recognizing the 213 area code in the Los Angeles
In Maryland, a
repairman was frustrated by repeated reports of crosstalk on a
particular foreign exchange (FX) line. After replacing several
defective line packs in the KTU, high loop current was
determined to be the problem. The constant high current would
eventually break down the line pack and crosstalk would return.