7 Ways to Use Twisted Pairs That Nobody Tells You About

7 Ways to Use Twisted Pairs That Nobody Tells You About

Twisted pair cabling is ubiquitous in telecommunications and computer networking. While many people are familiar with using twisted pairs for Ethernet networks, there are some clever and unusual ways to utilize this versatile medium that often go overlooked. In this article, I will share 7 creative ways to use twisted pairs that you may not have considered before.

1. Build Your Own Analog Phone Line

Most household analog telephone lines use twisted pairs to carry voice traffic. With some basic electrical components, you can actually build your own functional phone line using CAT5 cable.

To do this, you will need:

First, separate out one twisted pair from the bundle. Attach an RJ11 connector to each end. Then, connect pins 3 and 4 on each connector together using just one wire from the pair you set aside. This converts the twisted pair to a single analog line suitable for carrying voice.

Connect one RJ11 to your phone, and the other to a friend's phone or a telephone wall jack. You now have your very own analog phone line for making calls over short distances!

2. Construct a Twisted Pair Ethernet Network

While Wi-Fi gets all the hype these days, you can still build a perfectly functional and fast Ethernet network using only twisted pairs.

To create your own twisted pair wired network, you will need:

Use the crimping tool to attach RJ45 connectors to each end of the CAT5 cables. Follow the proper wiring standard (such as T568B) to ensure correct polarity.

Connect the cables between computers and the switch. Configure static IP addresses on each computer, and you've got yourself a twisted pair LAN! It's reliable, secure, and fast - up to 1Gbps with CAT5e.

3. Transmit Radio Signals Over Long Distances

With the right adapters, you can use twisted pairs to transmit radio signals over very long distances - much farther than possible over regular coaxial RF cable. This works by using impedance matching transformers to connect the twisted pair to radio equipment.

Some examples of what you can do:

This allows you to send RF communications across a whole city or between buildings on a large corporate campus. The relatively low loss of twisted pairs enables signals to travel for dozens of miles.

4. Deliver Power Over Long Cable Runs

Twisted pair cabling can carry not only data and voice, but power as well! Techniques like Power over Ethernet (PoE) use twisted pairs to deliver electricity to remote devices like IP cameras, VoIP phones, Wi-Fi access points, and more.

But even without specialized PoE equipment, you can use transformers and DC power insertion devices to send low voltage power over twisted pair lines. This enables you to:

By using multiple transformer taps, you can adjust the output voltage as needed by your devices.

5. Make Your Own DIY Magnetic Induction Loop

Twisted pairs come in handy for an unusual application - building a magnetic induction loop for the hard of hearing. These loops turn an audio signal into a magnetic field that can be picked up by hearing aids in telecoil mode.

To try this yourself, you just need:

Connect the loop amplifier outputs across one twisted pair. Install the loop antenna around the perimeter of a room. Send an audio feed from a mic or TV to the amplifier inputs. The loop will now emanate a magnetic signal containing the audio!

6. Transmit RS-232 Serial Data

Before USB became ubiquitous, RS-232 was the standard for serial communications. Twisted pair cabling can be used to transmit RS-232 signals using a technique called serial null modem emulation.

To do this, you need:

The null modem emulators convert the RS-232 signals to differential voltages that can be carried over the twisted pairs. This allows you to locate serial devices like industrial equipment hundreds of feet from the controlling computer.

7. Create Telephone Cables for Antique Phones

If you want to use an old antique telephone, you'll need the right 2-wire cable to connect it. While you can sometimes find original cloth-insulated phone wiring, it's also possible to fabricate your own cable using twisted pairs.

Any two conductors twisted together will work, such as:

Connect the wires to screw terminals or Western Electric phone plugs. Add a small phone ringer box if needed, and you're ready to call the operator!

Twisted pair cabling is inexpensive and offers great versatility for many DIY projects. With some electrical knowledge and the right equipment, twisted pairs can carry telephone calls, data, RF signals, power, or even magnetic waves. While it may seem like plain old ordinary cable, twisted pair has some extraordinary capabilities. The next time you have an electronics project, consider using trusty twisted pairs in one of these unconventional ways.