• Simulates 75W coaxial cable, WECO 728A (Belden 9231)

• Selectable cable lengths from 0ft to 1485ft (453m) in 45ft (13.7m) steps

• Noise mixer input provides variable S/N ratio simplifying interference margin testing to CCITT G.703 specifications

• Buffered 50W oscilloscope output (¼ level) provides end-of-line view of data signal for easy pulse mask verification

• Accurate over a 3 decade frequency range, from 100kHz to 100MHz

• Convenient front panel controls and display, calibrated in Feet, Meters, and dB of Attenuation at 4 standard frequencies

• Remote control of all functions via standard RS-232 port

Compatibility

• US and European AMI-PCM codes:

  DS2	-	6.312 Mb/s
  DS3	-	44.736 Mb/s
  CCITT	-	32.064 Mb/s
  CEPT	-	8.448 Mb/s
  CEPT	-	34.368 Mb/s

• SONET STS-1 - 51.840Mb/s

• Ethernet and other LAN protocols

• CATV and HDTV signals

• Design and evaluation of serial data receivers and repeaters

• Replaces almost 1500ft (453m) of 75W coaxial cable and multi-tap patch panels in laboratory experiments

• Allows automated testing of telecommunications, PBX, CATV, HDTV and LAN equipment

General Description

The ME-1005 is a highly accurate, programmable filter designed to simulate the attenuation versus frequency characteristics of the 75W coaxial cable, type WECO 728A (Belden 9231) specified by ANSI and CCITT for use in high speed communications networks in the US and around the world. This same cable is also found in office buildings and industrial complexes where it forms the backbone of PBX and LAN communication systems. By simulating almost 1500ft (453km) of coaxial cable in 45ft (13.7m) increments, the ME-1005 offers a convenient and practical method of developing and testing communications equipment intended for use in these high speed networks.

Easy to use front panel controls set the ME-1005's simulated cable length displayed in Feet, Meters, or dB of Attenuation at 4 standard frequencies (in MHz): 4.2, 17.2, 22.4, and 25.9. A 75W noise mixer signal input allows interference margin testing with S/N ratios from 9dB to 20dB in accordance with CCITT G.703 while a buffered 50W oscilloscope output simplifies viewing of individual data pulses for easy mask verification. All ME-1005 functions can be computer controlled via a standard RS-232 serial port for automated test applications. Options include a rack-mount chassis and battery backup.

 

Terminating Impedance .................................... 75W, ±5%

 

Recommended Frequency Range .... 100kHz to 100MHz

 

Maximum Input Voltage, Absolute

Zero to Peak ..................................................... ±5V

 

Maximum Input Voltage (<0.25dB Compression)

Zero to Peak .................................................. ±3.75

 

Sourcing Impedance (At 1MHz) ............. 75W/50W, ±5%

 

Maximum Rise/Fall Time At 0dB,

V_IN = 1V_PEAK-to-PEAK ........................... < 2nsec

 

Maximum Overshoot At 0dB,

V_IN = 1V_PEAK-to-PEAK ............................... < 5%

 

Short Circuit Tolerance .............................. Continuous

Attenuation range at f_o with display setting:

f_o = 4.2MHz ........................ 0dB to -7.9dB

f_o = 17.2MHz .................... 0dB to -16.7dB

f_o = 22.4MHz .................... 0dB to -19.4dB

f_o = 25.9MHz .................... 0dB to -21.1dB

Frequency dependent attenuation simulates that of 75W coax cable (WECO 728A) at 20ºC. The following table lists the cable attenuation (A₄₅) verses frequency at a length of 45ft.

The attenuation at any frequency, A(f), can be calculated as a function of the simulated cable length as follows:

A(f) = A₄₅(f) X (length/45ft)

CLICK ON GRAPH TO ENLARGE

Attenuation tolerance for both the LINE and NOISE inputs and LINE and SCOPE outputs at f_o display setting:

f_o = 4.2MHz ......................... ± 0.25dB

f_o = 17.2MHz ....................... ± 0.25dB

f_o = 22.4MHz ....................... ± 0.25dB

f_o = 25.9MHz ....................... ± 0.25dB

 

LINE input attenuation accuracy at any frequency is specified to a maximum of -20dB. NOISE input attenuation accuracy at any frequency is specified to a maximum of -40dB.

 

Attenuation tolerance at all other frequencies relative to f_o is given by the following graph:

CLICK ON GRAPH TO ENLARGE

General Specifications

 

Power input voltage:

Option A ...................... 103V to 132V

Option B ....................... 210V to 250V

Option J .......................... 90V to 110V

Power input frequency ..............................45Hz to 66Hz

Power consumption ................................................ 14W

Dimensions (w x h x d in inches) ............... 17 x 3.5 x 14

Weight .................................................................... 14 lbs

Storage temperature ............................... -40°C to 85°C