Radios allow players to transmit short in-game messages across large distances. Radio communication requires two ingredients: a transmitter and a receiver.
The simplest transmitter is made of a jukebox, a sign, and a redstone power source. To transmit a message, place the sign on the side of the jukebox and then power the jukebox with redstone.
The sign contains your message, and must have the frequency of your broadcast (that is, a number of your choosing) written in brackets on the first line of the sign. When the radio is powered, your message will repeatedly broadcast every few seconds, so no redstone clocks are needed.
However, in this state, your radio won’t broadcast very far. To boost the range of your radio, you must give it an antenna. An antenna is a column of iron bars built on top the jukebox. The range of your broadcast increases exponentially with the height of the antenna.
A radio receiver is a compass. To use the compass as a radio receiver, it must be in your hotbar. Radio receivers have two modes: tune and scan.
To tune a radio receiver to a specific frequency, hold the compass in your hand and type /radio tune <frequency>. The radio will then pick up messages broadcasted on that frequency, if the player is within range of the transmitter.
To scan with a radio, type /radio scan. The receiver then has a one percent chance of picking up broadcasts from any transmitter within range of the player. Once a random message has been intercepted, the radio automatically stays on that frequency until it is reset to scan mode.
The messages you receive may not come through with perfect clarity. If you are in the outer half of the transmitter’s radius, then the message will be a little bit scrambled. The transmitter can be configured so that message clarity drops off less quickly.
What can I set as the radio’s frequency?
- Any number you want. It can even have decimals, but will be truncated after two decimal places. (i.e. 100.1234 is the same as 100.12)
How is broadcast range related to antenna height?
- A radio without an antenna will broadcast 300 meters. With an antenna, the radio’s range follows this formula:
- radius = 300*1.023^n where n is the height of the antenna.
How do I make my message longer than one sign?
- You can continue your message by placing additional signs on the other sides of the jukebox. They will all be strung together to form your final message. You only need to write the frequency once, at the top of the first sign. Also note that spaces are NOT automatically added between signs, or between lines of signs. This lets you continue words from line to line for maximum space efficiency.
How do I boost the clarity of my signal?
- If you put an iron, lapis, gold or diamond block between the jukebox and the antenna, then your message will retain clarity over longer distances. Diamond gives the biggest boost, and iron the smallest (in order of increasing effectiveness: iron, lapis, gold, diamond). This clarity-boost block is an optional configuration.
Can I change the font color of my broadcast?
- Yes! You can do this (again, optionally) by putting wool block of the desired color between the jukebox (or clarity block, if present) and the antenna.
I was receiving radio messages just fine, then suddenly they got all garbled! Why?
- Is it thundering? During thunderstorms, the broadcast radii of all transmitters are temporarily halved. Immersion, fuck yeah!