The repeater network is an important building block in a larger network. The repeater itself receives a weak incoming signal, amplifies it, and sends it back to the same frequency on which it was received. Since the repeater station is listening for its own frequency, it can distinguish between signals intended for it and signals that aren’t.
The repeater then transmits the signal out over its coverage area on a different frequency. Since the signal from the source station (called the “input”) has been strengthened, the signal can cover more territory with greater clarity.
A repeater is a “duplex” in that it can simultaneously transmit and receive signals on the same frequency. This allows communication throughout the system without having to retransmit information from one receiver to another.
Repeaters can be connected over wide areas and long-distance using the internet through three primary ways:
1. EchoLink and IRLP
In the IRLP and EchoLink systems, the links between repeaters and individual stations are controlled manually by system users. If you want to connect to a system beyond your local repeater, you must manually enter the access code. The code will help identify the specific repeater system you want to use and the system in turn will set a connection and route your audio.
When you are done, a disconnect message ends the sharing. For EchoLink systems, users don’t have to have a radio because it can be accessed from the computer using the internet. You can use EchoLink whenever you cannot access a radio or when you are far from your home repeater.
D-STAR is a complete set of digital communication protocols for individual radios on its own. Communication occurs through streams of digitized audio over the air to another D-STAR radio or a D-STAR repeater. The repeater receives the digital stream of data and retransmits it as digital data. The voice signals can be shared or relayed easily over digital networks because it is already digital during the transmission time.
Therefore, it is not possible to transmit D-STAR signals through the regular FM voice radios and vice versa. D-STAR repeaters are connected to the D-STAR system through gateways. Ham radios establish links between D-STAR repeaters by entering call signs into their D-STAR radios. Calls to any ham are routed to their last known D-STAR repeater and you will not have to know the location of the person you want to contact.
3. IRLP reflector
IRLP nodes use the regular FM repeater with an internet link to relay digitized voice. A user can direct an IRLP node to connect to another IRLP code. Once the node-to-node connection is made, the audio from the two repeaters is exchanged in a way that may seem like the two users are using the same repeater.
IRLP reflectors are used to connect several nodes and exchange digitized audio data from one node to several others in real-time. Users who cannot access radio can join in using IRLP nodes or reflectors as long as they are licensed. From there, the user can enter the access code and connect.
The Internet to Connect your Repeater to a Ham Station
Many repeaters are linked together worldwide. When you use an internet-based repeater, your voice is converted to digital data and sent over the internet (often called VoIP or Voice Over Internet Protocol). This data is then converted back into an audio format for the other repeater and transmitted via radio.
The big advantages to this approach are no need for special hardware on the receiver side, low delay, cost savings for both repeater owner and user, good quality sound, and freedom from radio propagation issues.
You can make contact with other hams using either of the above ways from wherever you are as long as you follow the contact protocol.
As ham radio operators, many of us have used repeater networks to communicate with others. In fact, it is thanks to the repeater network that we can have long-distance communications using just handheld radios.
If you are new to ham radio and are wondering how to set up your own repeater, the above article has given you the basics about how it works. Ham radios are still a hot-selling item despite being around for ages. You can pick one up for about $40 or so, get a license and build your own radio. Getting a ham radio license is not difficult and will open up a brand new world for you where you can talk to other people you never thought you could reach.