USB Port Hub – Useful for Digital Operators

With the availability of more and more digital modes and devices in amateur radio, need for USB connectivity to the laptop computer is increasing. You need one USB port exclusively for CAT control of the radio. Very often the limited number of USB ports available in your laptop are already in use for mouse, keyboard, external monitor, printer and sometimes even an additional webcam. Often we need a USB Port Hub to add on additional USB devices. Only bottleneck in using a USB Port Hub which I have experienced is that often they have loose contact and intermittent connectivity in one or other of the available extra ports. This USB Port Hub has three ports on the long side and one on the short side.

Here I have a view of the internal structure of the USB Port Hub as I happened to open up a damaged one. Two major components which you can see other than the four USB ports on the printed circuit board are a 28 pin integrated controller and 16 V 47 MFD electrolytic capacitor. You can see four wires terminating on the PCB, coming from the USB plug connected to the computer. The red and black wires supply DC power while green and white wires carry data traffic. You can also see a few resistors and capacitors as well.

This USB port hub does not have a separate power supply, meaning that it will draw power from the computer to which it is connected. There are more sophisticated USB port hubs which have their own power supply and are able to give more power to the devices connected to them. But then they will will have a separate power cord which would make them more cumbersome to use and reduce portability. Yet such hubs may be needed if you are planning to connect a device which needs more power like a large external hard drive.

USB port hubs without an external power supply like this one can be used for keyboards, mice, flash drives, low power speakers, USB to LAN converters and mobile phones. Of course, this will not have the facility for quick charge in the newer mobile phones. As expected, USB ports in a USB port hub will share the available bandwidth which could be 5 GBPS for a typical USB 3.0 connection from a laptop computer. USB ports typically operate at 5 V and provide 500 mA current. So a USB port hub without external power supply can provide only four additional ports as it needs 100 mA current for itself and supplies 100 mA to each of the other ports. Self powered USB Port Hubs on the other hand can supply 500 mA current to each of the ports, if they have a compliant external power supply.

USB Port Hubs also support hot swapping, meaning that you can unplug a device from the hub without having to power off the computer first. This enables us to quickly connect or disconnect devices freely.