3261AAB是透过单一治具，针对通信变压器的自动测试仪，搭配3260B精密磁性元件分析仪使用，能量测插损（IL）及回损（RL）、纵向平衡及横向平衡、总谐波失真（THD）这些参数能透过3260B精密磁性元件分析仪的图形选配功能（/G graph option)绘制图形并可列印输出。

Telecom Unit - 3261A

Automatically tests telecom transformers in a

production environment

Measures Total Harmonic Distortion, longitudinal

and transverse balance and Insertion Loss and

Return Loss

Fast, accurate and repeatable automatic

measurements

Straightforward intuitive operation

Graph longitudinal and transverse balance, and

insertion and return loss against frequency

Suitable for ADSL, HDSL, ISDN, analog line

matching transformers and POTS splitters

Accurate DC bias current

Low cost compared to comparable equipment

Telecom component characterisation

3261A Telecom Unit forms the core of a comprehensive

component test system. It is configured in conjunction with

the Wayne Kerr 3260B Precision Magnetics Analyzer to

carry out a wide variety of telecom-related measurements.

Telecoms Fixture model 1008 further enhances the test

capability by providing an interface to connect units under

test such as transformers.

Complete telecom transformer

characterization

Automatic production testing of telecom transformers

is available with the 3261A. Transformers are

characterized at the press of a button.

Total Harmonic Distortion

Providing unrivalled Total Harmonic Distortion (THD)

performance this optional function displays the second,

third, fourth and fifth harmonic as well as THD.

Measurements as low as -110 dB can be carried out;

the user can set a large number of preset fundamental

frequencies from 150 Hz to 200 kHz.

Longitudinal balance and transverse

balance

This optional function provides longitudinal balance

and transverse balance measurements in line with

IEEE 455, ITU recommendation O.9 (O.121) and FCC

68.310 over the frequency range 200 Hz to 3 MHz.

Measurement capability is high, longitudinal balance

accuracy is ±1 dB over 80 dB, ensuring that devices

can be measured with confidence.

The longitudinal and transverse balance of any

component can be completely characterized

graphically across the full frequency band enabling

component performance to be analyzed in more detail

Insertion Loss and Return Loss

3261A Telecom Unit measures Insertion Loss and Return

Loss from 20 Hz to 3 MHz on transformers and POTS

splitters.

The instrument can also measure and display many

parameters including Insertion Loss and Return Loss

against frequency in a graphical form - ideal in a design or

development environment.

Swept measurements in graphical form

It is often important to characterize component

performance outside its operating range, especially during

component design. The 3261A allows Insertion Loss,

Return Loss, transverse and longitudinal balance, and the

usual basic transformer parameters, such as Inductance

and interwinding capacitance, to be displayed graphically.

Sweeping the full frequency band for the particular

measurement the user can identify the maximum and

minimum point on the graph and a moveable marker

displays the frequency and level. The graph axes can

be selected as either a logarithmic or linear scale.

Comprehensive test system

The key to the test system’s versatility and accuracy is

the combination of a precision impedance analyzer

with a dedicated telecomms test unit. This

combination provides many advantages.

Where special interface methods are needed the 1008

Telecoms Fixture is available, or customised fixtures

can be configured using a blank fixture to ensure high

integrity measurements.

3261A Telecom Unit is the core of a comprehensive test system which also incorporates

3260B Precision Magnetics Analyzer and Telecoms Fixture model 1008

ADSL, ISDN and HDSL analogue line matching

transformers and POTS splitters

ADSL technology requires tighter specifications and

additional measurements when testing line matching

transformers. The 3261A provides all the required

measurements and performance for ADSL technology,

including Total Harmonic Distortion, longitudinal and

transverse balance, Insertion Loss and Return Loss.

It not only exceeds the required specifications but also

makes all the measurements automatically from the same

fixture. For the user it is just a case of connect and test,

ideal in a production environment, with no complex setups,

special jigs or the need to calculate the result from a

number of voltage measurements - the 3261A does it all.

The user is able to select the required line side

termination from a list of predetermined values.

Equipment side terminations are provided by the user

and can be connected to the appropriate socket on the

3261A. Once the termination has been fitted no

further interaction is required by the user.

Accurate DC bias current

DC bias current can be selected for Insertion Loss,

Return Loss and Total Harmonic Distortion.

This function provides high accuracy user selectable

DC current in the range 1 mA to 200 mA in 0.1 mA

steps (to 20 mA) and 1 mA steps (to 200 mA).

The total production test solution ... in a single fixture

Replacing many discrete instruments, complex jigs and

difficult measurements, the 3261A Telecom Unit provides

all the functions needed to meet the new telecom

standards in a single multi-function unit.

It also replaces all the hard work, high skill levels and

uncertainty of manual testing by handling all the complexity

internally and presenting the user with the information

required quickly and accurately. In a production

environment it is just a case of connect and test.

All the user has to do is press the start button and the

3261A Telecom Unit makes all the measurements and

displays a Pass/Fail banner.

Technical specifications

Telecom Unit – 3261A

General

Line side termination: 50, 75, 100, 120, 135, 600, 900 Ω

Equipment side termination: Customer is required to supply

centre tapped 1% resistor

Insertion Loss

Drive level*: -65 dBm to +20 dBm

Drive level units: dBm, dBμV, V

Frequency range: 20 Hz to 3 MHz

Basic Accuracy**: 0 to -3 dB ±0.1 dB

*Varies with line impedance

**Varies with frequency

Return Loss

Drive level*: -60 dBm to +25dBm

Drive level units: dBm, dBμV, V

Frequency range: 20 Hz to 3 MHz

Basic Accuracy**: 0 to 25 dB ±1dB

25 to 30 dB ±2 dB

30 to 35 dB ±3 dB

*Varies with DUT impedance

**Varies with frequency

Transverse balance (analogue voiceband)

Drive level: 0 dBm (0.775 V rms)

Frequency range: 200 Hz to 10 kHz

Basic Accuracy: to 80 dB ±1 dB

Transverse balance (digital)

Drive level: 0 dBm (0.316 V rms)

Frequency range: 10 kHz to 3 MHz

Basic Accuracy:

to 55 dB ±1dB (≤1.55 MHz)

to 45 dB ±1dB (>1.55 MHz)

45 dB to 55 dB ±3 dB (>1.55 MHz)

Longitudinal balance

(analogue voiceband)

Drive level: 1 V rms

Frequency range: 200 Hz to 10 kHz

Basic accuracy: to 80 dB ±1 dB

Longitudinal balance (digital)

Drive Level: 0 dBm

FrequencyRange: 10 kHz to 3 MHz

Basic Accuracy:

to 55 dB ±1 dB (10 kHz to 1.1 MHz)

to 45 dB ±1 dB (>1.1 MHz)

45 dB to 55 dB ±3 dB (>1.1 MHz)

Total Harmonic Distortion

Maximum drive level: 6 V rms (±2%) at the DUT

Drive level units: Vrms, Vp-p, dBm

Frequencies: 150, 300, 500, 600, 5k, 10k,

15k, 20k, 25k, 30k, 40k, 50k, 100k, 150k

and 200 kHz

DC bias current

Output current: 1 to 200 mA

Step size: 0.1 mA (1 to 20mA), 1mA (20 to 200 mA)

Basic accuracy: ±1% ±1 μA (1 to 20 mA),

±1% ±10μA (20 to 200 mA)

Compliance voltage: 22.5 V (into line side termination)

Power Supply

Input voltage: 115 V AC ±10% or 230 V AC

±10% (selectable)

Frequency: 50/60 Hz

Environmental

Installation category: II (in accordance with IEC664)

Temperature range: Storage -40°C to 70°C,

Operating 0°C to 40°C. Full accuracy 15°C to 35°C.

Relative humidity: up to 80% non-condensing

Pollution degree: 2 (mainly non-conductive)

Altitude: up to 2000 m

Safety

Complies with the requirements of EN61010-1

EMC

Immunity: EN61326-1

Emissions: EN55022 Class A

Mechanical

Height: 150 mm (6″)

Width: 440 mm (17 3/8″)

Height: 520 mm (20 1/2″)

Weight: 14 kg