Network cable tester

[mike_mike]

Hello! I would like to build a network cable tester based on 555, 4017, led's and a few more components. I would like to test UTP, STP and FTP Cat5e and Cat6 cables, which uses shielded RJ45 and unshielded RJ45 connectors.
I want to mention that I need led's on both emitter and receiver of the tester, to see if the wires are swapped.
This is the first schematic that I found: http://www.frankshospitalworkshop.com/electronics/diy-lan_cable_tester.html - I used a 9V battery, and I replaced the 47R resistors with 470R resistors.
This is the second schematic:
1. Transmitter: https://danolteanu.000webhostapp.com/testerrj45.gif
2. Receiver: https://danolteanu.000webhostapp.com/receiverrj45.gif

I built the first schematic, and it is working, but then I needed led on the receiver part, and then I built the receiver from the second schematic (2).

I wanted to know if there is possible to make some simple improvements to this schematic ?

[danolteanu]

Hi,
I've designed the second schematic.
Build the transmitter and the recevier and it works perfect, no improvements necesarry.

BR/Daniel

[liaifat85]

Oh.The circuit designer himself is here! I believe, now you'll get the most authentic help regarding your network cable tester.

[madires]

Looks very similar to the inexpensive 'LAN testers' sold for 10 bucks (the design is 20+ years old). They are great for checking continuity.

[SeanB]

Yes, the only improvement would be to have a small 8R speaker in the Vdd of the 4017, so that each transition provides a small click, and also if the connections are intermittent you will get noise out of the speaker, telling you of an intermittent joint in the cable.

Also add a 1000uF 25V capacitor across the supply pins of the 555 timer, which will help with stability as the 9V battery ages.