GT-2B PCM Channel Characteristic Analysis

The GT-2B PCM Voice Channel Characteristic Analyzer is a portable communication instrument used for testing various indicators of voice channels. It is widely applied in testing PCM terminal equipment, digital switches, carrier communication equipment, user dispatch systems, and VoIP-based devices. It is suitable for research, production, engineering installation, acceptance, and maintenance.

Main Features of the GT-2B PCM Voice Channel Characteristic Analyzer:
● Handheld voice channel characteristic analyzer;
● Full Chinese menu, large screen display, easy operation;
● Supports multitasking (can test while reviewing previous records);
● Built-in test templates with graphical display;
● Built-in DC loop feed circuit and DC loop hold circuit;
● Ergonomic design with an intelligent navigation-style Chinese interface for simple and convenient operation;
● Large LCD screen, 320×240 dot matrix, LED backlight;
● Equipped with a high-speed micro printer and external printer interface;
● Embedded software supports online upgrades.
Basic Functions of the GT-2B PCM Voice Channel Characteristic Analyzer:
● Point level, frequency response, level characteristics, quantization distortion, idle noise, inter-channel crosstalk, echo loss, and ground balance testing;
● End-to-end testing, loopback testing;
● Single-channel or 30-channel automatic testing with report printing;
● Fully automatic and manual modes; fully automatic mode allows selecting one, several, or all measurement indicators with programmable test step intervals;
● Stores up to 60 sets of measurement results and up to 9 test configurations with power-off memory;
● Built-in generator and receiver; output and input ports feature DC loop feed and hold circuits, enabling testing of E&M two/four-wire interfaces, as well as LGE, FXO, LGS, and FXS interfaces;
● Graphical display of test results, comparable with built-in ITU-T standard templates for clear pass/fail assessment;
● Stored measurement results can be uploaded to a PC for analysis, organization, archiving, and printing.
Technical Specifications of the GT-2B PCM Voice Channel Characteristic Analyzer:
● Generator Signal frequency: 100Hz–4000Hz, step 10Hz
Output level: +6 to -61dBm0, step 1dB
Relative level: +1 to -17dBr, step 0.1dBr
Distortion: ≥50dB at 1020Hz/0dBm0
Frequency response: ±0.1dB
Output impedance and return loss: 600Ω within 200–3600Hz, return loss ≥36dB
Output balance: ≥60dB within 200–3600Hz

● Receiver
·Level Frequency range: 200Hz–3600Hz
Level range: +13dB to -78dB, including dBm0 from +6 to -61dBm0, dBr from +7 to -17dBr
Measurement error: ±0.2dB at 0dBm0 point, ±0.3dB at other points
Reference signal: 1020Hz/-10dBm0
·Frequency response Reference signal: 1020Hz/-10dBm0
Frequency range: 200Hz–3600Hz
Measurement range: -60dB to +60dB
Measurement error: ±0.2dB
·Level characteristics Reference signal: 1020Hz/-10dBm0
Level range: +5dBm0 to -60dBm0
Measurement range: -60dB to +60dB
Measurement error: ±0.2dB
·Idle noise Auxiliary signal: Off
Measurement range: -90dBm0p to +5dBm0p, ITU-T weighted
Measurement error: -90 to -75dBm0p: ±2.5dB
-75 to -70dBm0p: ±1.5dB
-70 to +5dBm0p: ±1dB
·Inter-channel crosstalk Main signal: 1020Hz/0dBm0
Measurement range: -90dBm0 to +5dBm0
Error range: ±1 dB
·Quantization distortion Reference frequency: 820Hz
Level range: +5dBm0 to -60dBm0
Measurement range: 0–60dB, ITU-T weighted
Measurement error: ±0.8dB
·Echo loss Test signal frequency range: 200Hz–3600Hz, level 0dBm0
Measurement range: 0dB–62dB
Measurement error: ±1dB
·Ground balance Test signal frequency range: 200Hz–3600Hz, level: 0dBm0
Measurement range: 0dB–82dB
Measurement error: ±1dB

·Input impedance and return loss: 600Ω within 200–3600Hz, return loss ≥36dB;
·Input balance: ≥60 dB within 200–3600Hz;
·Interface balance: 600Ω, 200Ω+560Ω//0.1μF; 200Ω+680Ω//0.1μF;
·Relative level: -17 to +7dBr, step 0.1dBr;
·DC loop: IGT dynamic impedance >100kΩ, loop current 60mA, loop voltage drop approx. -15V;
OGT dynamic impedance >100kΩ, feed current constant 22mA.

Other Parameters of the GT-2B PCM Voice Channel Characteristic Analyzer:
● Power supply:
(1) Instrument power adapter
INPUT: AC220V 50Hz
OUTPUT: DC 9V 1.2A
(2) Internal rechargeable battery
4000mAh 6V Ni-MH rechargeable battery
Operating time: 6 hours
Charging: 8 hours when powered off; 12 hours when powered on
● Printer: μP40-TS(CH) standard level serial port Chinese micro printer (optional)
● Dimensions and weight:
Length × width × height: 220×162×48mm
Weight: 1kg
● Environmental parameters:
Operating temperature: 0–40°C
Storage temperature: -20 to +70°C
Humidity: 5%–90% non-condensing

Application Examples of the GT-2B PCM Voice Channel Characteristic Analyzer:

Four-wire testing of indicators such as "point level/frequency response/level characteristics":

Four-wire testing of "inter-channel crosstalk":