GAOTek Tel Line Tester

This compact Telecom Line Tester comes with basic line tester functions, auto ringing and checking line pair also comes with high voltage protection and high voltage alarm indicator



GAOTek Tel Line Tester is a new kind of line fault tester with safety & multi-functions capabilities. Besides the functions as a common Tel Line Tester, it also has the functions of high voltage protection and dangerous voltage warning, etc. The major applications of this instrument include testing for insulation and locating faults in the line.

Key Features

  • DTMF is applying to GB/T15279-94
  • High voltage alarm
  • Low voltage warning
  • Last number redial
  • Durable test clamp
  • Automatic power off and energy-save design
  • Pocket size and simple operation


  • Telephone functions (Dial, redial, talk and hook).
  • Fault tests (Insulation test, line break test and earthing test).
  • Call subscriber & talk.
  • Check line pairs.
  • Low battery check.
  • High AC Voltage alarm.

Technical Specifications

Insulation impedance test
Range 0~10 MΩ
Ring distance ≤ 0.6 mi (1 km)
Line Break Resolution ≤1.86 mi (3 km)
Weight ≤ 0.49 lbs (0.22 kg)
Dimension 5.74  in x 2.13 in x 1.46 in (146 mm ×  54 mm × 37 mm)
Battery 9 V layer battery

Operating Instructions


1. Dial, redial, talk and hook

In normal condition, talking mode is default. You could press Hook to end talking, and press Redial to redial.

2. Pulse/Tone dialing

Please place P/T button on the P position the tester could perform pulse dialing. On the contrary, if the P/T button on the T position it means it could perform double tones dialing now.

3. Fault tests

Link Test line to subscriber’s line, then the product could perform the following tests:

4. Insulation test: In normal condition, press test key to test insulation. And the product indicates the insulation through 4 LEDs.

4 LEDs shining: Serious stranded or mix (0~3 k).

3 LEDs shining: Mix or serious bad insulation (3~20 k).

2 LEDs shining: bad insulation (20 k~2 M),

1 LED   shining: Low-degree bad insulation (2 M~10 M), it could

4 LEDs dark: Good insulation (≥100 MΩ), fit for telephone & data service.

Line break test: Press Test key, if the LED flashes from right to left quickly with very brief whistle, it indicates the line is broken. Contrariwise, if flash slowly with a long whistle it means the line is not broken.

Earthing test: link black clamps to earth line to test the earthing. Insulation LEDs show the degree of earth insulation.

5. Call subscriber & talk

Link Test line to a subscriber’s line to test, press Talk key. After its LED is shining, then press Test key intermittently, to call subscriber’s telephone (If Call LED is green and shinning it means the signal has been sent out). If Talk LED (key 7) is on it indicates the subscriber on hook, then enable to talk. This function can be used to check line maintenance.

6. Check line pairs

We can check line pairs with the product (Party A) and other available telephone or tester (Party B). First, Party A and Party B are in normal condition and talk to each other. Party A links red clamps with any core line and this core line is regarded as the assistant line now. Please let Part B link the assistant line to the core line to test. The man of party B connects assistant line with the core line to test. Now let Party A make the test line linked to test ring touch the core lines to test and keep in communicating mode with Party A. Then, the man of party A makes every core line touched by test line C connecting to line pair ring…until both sides hear a flute sound, which means Party A and Party B shares the same core line. Then check the other line in the same way.

1. High AC V alarm

Press Redial there is alarm sound and High AC V LED 6 on when the product is near the line, which has high AC V. Please take care!

2. Low battery & change

Press Talk, Hook and Test at same time, loud whistle indicates battery is sufficient, otherwise, it means the battery is exhausted please change the battery.


★Battery free for dialing and monitoring. The battery supporting for fault testing, ringing up subscriber and checking wire pairs.

★High-volt alarm LED (key 8) on, indicate dangerous, take off the clamp as quickly as possible.

★Loosen “Talk” when the tester is off operation. Pick out the battery if long time off operation. The distance of voltage test is related to the high/low of the voltage which is tested, the test environment and the weather; the voltage which is tested is higher, the distance of electromagnetic eradiation is longer, the distance is longer; rain, snow and fog absorb part of electromagnetism, therefore, test distance is short; if there are other bars such as the trees, wall and so on, and they can absorb a part of electromagnetism and the distance is small.


  1. Hook
  2. Redial
  3. Test
  4. Talk
  5. Receiver
  6. High AC V LED
  7. Communication LED
  8. High-volt LED
  9. Talk LED
  10. Line pairs ring
  11. LCD
  12. Number key
  13. MIC
  14. P/T button
  15. Switch box
  16. Test line
  17. Clamp