Do you have the right cable for the job? In this video, you’ll learn about RJ11, RJ45, F-connectors, punchdown blocks, USB, USB-C, Molex, Lightning, and DB-9 connectors.
We’ll start our conversation of copper connectors with one that is relatively common, an RJ11 connector. This is a 6-position connector with two conductors inside. Sometimes you may see this written as 6P2C. Sometimes you’ll see this with four wires or four conductors inside, which technically makes it an RJ14, but generally speaking, we call them all RJ11 connectors.
This is the type of connector that you will commonly use if you’re plugging into an analog telephone connection, or more recently, a DSL, or Digital Subscriber Line, connection. So if your internet connection uses these telephone cables to bring in that digital signal with DSL, then you’re using an RJ11 connector.
A larger version of this modular connector is an RJ45. That stands for Register Jack type 45. This is an 8-position connector with eight conductors inside, and you can count all eight of those conductors in this single connection. This is also referred to as a modular connection. Sometimes we refer to it as an ethernet connection because it is very commonly used for ethernet networks, but RJ45 connectors can be used for serial connections and many other connection types as well.
There are slight differences in the size of an RJ11 versus an RJ45. They’re next to each either here on the back of this DSL modem. You can see, the RJ11 is slightly smaller than the RJ45 connection. Unfortunately, this makes it very easy to make a mistake if you’re reaching behind a device to plug things in because you could accidentally plug in an RJ11 connector into an RJ45 connection.
The RJ45 connector, of course, is too large to fit into the RJ11, so you’ll just need to double-check and make sure that when you’re plugging in RJ11, that you’re really plugging it into the appropriate interface.
One common type of coax copper connection is an F connector. The F connector is commonly used for cable television connections, and of course, this also extends into the cable modem connection.
Obviously, your coax is coming in from your cable provider or internet service provider, and the F connector commonly has this threaded connection at the end so that you can screw it into the connection and it’s not easily going to be removed from that connection without unscrewing it. In the very middle of this coax is the single copper connector that’s used to send and receive signals over that cable connection.
If you were to look at the specifications for your cable modem, you would see that it follows the standard of DOCSIS, which is Data Over Cable Service Interface Specification. And that DOCSIS modem that you’re using for your cable modem is connecting to the cable modem network using that F connector.
Here’s the connection on the back of a cable modem. You’ve got the female F connector on the cable modem itself, and this is the coax cable with an F connector on the end of it that’s used to screw into that cable modem connection.
If you’re working in a building where there are hundreds or even thousands of twisted-pair cables, then you may have large walls of punchdown blocks that are used to terminate those wires. These punchdown blocks are used because they are very fast, you can simply push the wire into the connection and punch it down with the appropriate tool, and it’s also relatively inexpensive.
You don’t have to put an individual connector on each individual wire. You simply place the wires into the appropriate spot on the punchdown block, you use your punchdown tool to quickly attach those wires into the block, and now you can move to the next set of wires.
Here’s a closer view of the unshielded twisted pair cable that has the individual wires inside, and you can see the eight wires on the inside of this cable have been punched down into the eight connections on this punchdown block. If you look closely, you can even see the metal contacts on the inside of the punchdown block that are able to pierce the insulation of these wires and make contact with the copper that’s inside.
Here’s a similar punchdown block. In this case, the wires are run on the outside, and the wires themselves are individually punched down to the individual connectors on the punchdown block.
Some of the most common copper connectors you’ll run into are USB, or Universal Serial Bus. If you’re running USB version 1.1 or 2.0, then you’ll probably see a Standard-A plug, very similar to this one. The Standard-B plug is a more square plug that’s used for peripherals. And if you’re using a mobile device, you’re probably using a Mini-B plug or a Micro-B plug.
If you’re running a later version of USB– for example, USB 3.0, your A plug is very similar in size to the previous version, but you’ll notice, the Standard-B plug and the Micro-B plug are very different in this newer version of USB.
We realized having all of these different USB interfaces creates additional cables and additional confusion. So instead, we have encapsulated all of these different connector types into one single type of USB connector called USB-C. USB-C is the physical connector type, which means we can run different types of signal over that same connector. For example, you could run USB connections over this, thunderbolt, HDMI, and many other types of signals.
If you’re working in an older desktop, you may find that there is a 4-pin power connector used to power a number of peripherals inside of that computer. This 4-pin connector is referred to as a Molex connector. Technically speaking, the connector itself was created by a company named the Molex Connector Company, so to call this a Molex connector is only one of many different kinds of connectors made by the Molex Connector Company.
You’ll also see this connector referred to as an AMP Mate-n-Lok. This is a connector that provides power for fans, storage drives, and other components inside of your computer, and it commonly provides 12-volt and 5-volt power.
You’ll often see the Molex connector paired with the power input for the fan or storage drive that you need to power. These are relatively modular, and they often connect to each other with simply friction, so it’s relatively easy to disconnect and reconnect them again.
If you look at one of these older power supplies, you’ll see that Molex connectors are included with the other connector types for that power supply. If we look a little closer, you can see other connectors such as the main motherboard power, and of course, there are the Molex connectors that are used to power those internal peripherals.
Many of our newer mobile devices use USB connections to be able to connect to power and data sources, but if you’re using an older device from Apple, you may be using a Lightning connector. Lightning is an Apple proprietary connector, so you’ll only see this used with other Apple products, and it’s usually associated with iPhones, iPads, and other similar devices.
When Lightning was introduced, Micro-USB was the style of connector that we commonly saw on mobile devices, but Apple wanted some additional power capabilities for their phones and their tablets, and they wanted a connector that could be inserted either way and still operate normally. Although the industry is moving towards USB-C as a standard, you may still find some devices using these Lightning connections.
If you’re a system administrator or a network troubleshooter, then you’ll need a DB-9 connection to connect to some of the older switches, routers, firewalls, and other devices. These DB-9 connectors commonly transmit serial communication, and the standard for that communication is RS-232. Stands for Recommended Standard 232, and it’s been around in the industry since about 1969.
These days, we commonly use USB as our standard form of serial communication, but before we add USB, we had RS-232 running over these DB-9 connections. So if you were plugging in a modem or a mouse, you were probably using DB-9.
These days, we still keep these in our bags because there are a number of switches, routers, and other infrastructure devices that use this type of connector as their console port. If you need to be able to directly connect to these devices and configure them at a command prompt, then you’ll want to use the serial port connection that often is using a DB-9 interface.