Brief Introduction

ST220B is a compact telephone line tester combining basic line tester function, auto ring, calling subscriber, checking line pair and high voltage protection. It is rather a good portable, handheld tester to the lineman.

Main Functions

Telephone functions (Dial, redial, talk and hook)

Fault tests (Insulation test, line break test and earthing test)

Checking wire pairs

Call subscriber & talk

Pulse/Tone dialing 

Low battery check.

Key Features 

DTMF applying to GB/T15279-94

High voltage alarm

Low voltage check

Last number redial

Special durable test clamp

Automatic power off and energy-save design

Pocket size, simple operation

Technical Specifications