Introduction:
CAT3 8158 is produced by Germany Schwarzbeck and authorized by Shenzhen EUTTEST agent sales of T8-ISN that is, 8-wire impedance matching network, with theCAT5 8158 The difference is that CAT3 is suitable for CAT3 network cables. CAT38158 conforms to ( LCL = 55 dB ) standard CISPR 22 edition 5.2 - Figure D.3 for 4-pair wire UTP, the design schematic is shown below:

schematic design
The ISN CAT3 8158 allows to perform common mode interference voltage measurements on unprotected twisted pair (UTP) or communication ports with 2, 4, 6 or 8 conductors according to CISPR 22:2005 or EN 55022:2006. It has connectors to accommodate a wide range of network cables, as shown in the figure below:

The connectors can be adapted to a wide range of network cables
In addition to measuring the interference voltage, the CAT3-8158 allows measurement of the immunity in progress. CISPR 24 or EN 55024 up to 80 MHz. For testing IEC 61000-4-6 an additional 50 Ω-150 Ω impedance conversion option (EAB8 50-150) is required, which can be easily mounted on the CAT3 8158 and is available as an option.
The CAT3 8158 also meets the AAN device requirements for CISPR32, details of which can be found by clicking on the link below:
How to select ISNs and AANs by test standard requirements?
Technical parameters:
<<<<提醒:左右滑动表格>>>>Model number | CAT3 8158 |
Instrument name | Impedance Stabilization Network |
Applicable test cable types | CAT3 Cable |
producers | Schwarzbeck |
agent | Shenzhen EUTTEST |
ISN mode available frequency range | 150 kHz - 30 MHz |
Frequency range available in CDN mode | 150 kHz - 80 MHz |
Product Type | T8, T4, T2-ISN, CDN (EAB8 50-150 required) |
insertion loss | typ.: < 1 dB 150 kHz to 30 MHz typ.: < 2.5 dB 30 MHz to 250 MHz CISPR 22, Appendix D, Fig. D.3 |
Decoupling AE-EUT | >55 dB |
LCL longitudinal conversion loss | 55 dB @ 150 kHz 39 dB @ 30 MHz |
agent | Euttest.com |
partial pressure coefficient | 10 dB ± 1 dB |
AE EUT Connectors | RJ-45 |
Maximum current | 800mA per pair of wires |
Maximum voltage | 63 VAC / 100 VDC |
RF connector | BNC |
weight | 465g |
size | 125 mm x 62 mm x 105 mm |
Illustration of technical parameters:

S21 curve

LCL Longitudinal Conversion Loss

voltage divider

Impedance graph

phase portrait