Review of use of ST-301 "SPIDER" when checking wired communications in the typical office premise.

In 2019 the new updated version of the wire lines analyzer has been released called ST-301”SPIDER”. Main differences of the new version from previous ST-300, are:
-Compact size
-The main unit and the electronic switch are in one body
-The adapter for connecting to the Power line has been reduced to the size of a “plug”
-Cable locator has been removed from the set

Main innovations are:
-PC software
-Controls through USB from PC
- Creation of reports on the measurements made, for registration of the line passport and comparison of changes with reference values.
-The connections cables kit was supplemented because kit for checking coaxial cables appeared.
-Accessory for checking shield cables has been added.

The changes In the new version can be valued positively. The cable locator ST-300 obviously had not answered to the high level of the cable analyzer it self , set by the manufacturer. Who needs the cable locator when You can purchase ST-600 instead.


The analyzer ST-301 became lighter and more compact.


Creation of reports gives new opportunities when doing special searching of the same premises during time, such reports usually are being used in the radio controlling systems.


The set of extensions and couplers became truly universal.


In the first part of the review dedicated to the ST300, we performed measurements using a set of test devices. The measurement procedure and actions with the st300 and ST301 interface are identical. Let's look at how the ST301 analyzer works with a PC. The driver for connecting ST301 is installed from the USB flash (included). The program for working with ST301 is not installed on a PC, but is launched from a flash drive. Report files are saved in the root st301\ST 301_prog\reports.


ST - 301 kit
Adapters, connecting wires from the ST-301 kit
Test kit analyzers, wire lines and time-domain reflectometer:
1. Midrange generator with parallel connection to the telephone line
2. Midrange generator connected to the 220V network
3. Microphone powered by the city telephone network
4. Microphone connected to a free pair of low current lines
5. RF generator with parallel connection to the telephone line
Telephone line urban PBX connector RJ-11
100 MB Ethernet line RJ-45 connector
Line of AC 220V 50Hz, the European wall socket


Wired receiver mode-Power line
Connect the 220 V adapter and select "Wired receiver"-"power line" in the ST301 menu»
Connect the PC, run ST301.exe
Main window of the program on the PC


Clear line





From the spectrogram and table, the dynamics are obvious. The simulator works at the frequency with the maximum signal level.

Save the report to the WRx folder. In addition to screenshots, the report will contain EXCEL tables.


Low frequency amplifier (LF) and Nonlinear locator (NLJD) mode

Determine the type of connector. We measure the voltage on 2 pairs of telephone lines in LFA mode by connecting the analyzer to a telephone outlet.
Connect the phone and 4-wire line to the analyzer using the adapter from the ST301 kit.



Select the NLJD mode and determine the connector type. Start scanning.



On the pair 4-5 the signal of telephone station "hearing aid hung up". Non linear junction detector indicates that on pair 4-5 telephone apparatus, on pair 3-6 nonlinearities. Let us switch in to LFA and supply Bias Voltage +5V and engage scan. Then change the polarity to -5V and start the scan again. 



On pair 3-6 we see consumption 0,76V, select the pair and on the oscillogramm and see the dynamics.


In headphones, we listen to the acoustics of the detected microphone. Stored in the report.

Reflectometer Mode.


Connect the switching unit to an RJ45 socket. Connect the ST301 via a seven-meter long cable. The shortening coefficient is 1.5. We perform reference measurements and save them on a PC.


We simulate the breakage of two wires in cable 3-4. We make measurements and compare them with the reference value saved earlier. The graph of reference values is highlighted in red.


When comparing pair 1-2, you can see that there are no changes.


From the comaprison graph and measurement table, it is obvious, that on the line 3-4 there is a break. The distance to the break is 6,4 meters. We would like to remind You, that the length of our cable is 7 meters,because the Velocity Factor 1.5 was selected without confirming the brand of the cable, such error is understandable. According to the methodics, shown in description to ST-301, it is necessary to make masurement on pair 3-4 from the other side, in all modes, for acquisition of additional signs and localisation of "eavesdropping device". 


Advantages of ST301:
Creating a reference measurement database for Ethernet and telephony" workspaces"
Reduced time for checking wired communications
Check the on-screen conductor
Check the coaxial cables
Reduced dimensions

Suggestions to the producers:

Add rj45 and rj11 cables, at least 7 meters long, to the kit for working with the reflectometer.

Text published by company Business Security LTD.


Silutes pl. 2 (Office No 525, 5th floor),
Klaipeda 91111, Lithuania
Phone: +370 655 08288, +370 655 08286
Fax: +370 46 411353