Simplex nodes, repeaters and hotspots
A plain comparison of the ways radios get linked together, and which license each one needs.
Side by side
| Type | How it works | Typical use |
|---|---|---|
| Simplex | Two radios talk straight to each other on one frequency | Short range chat, events, family |
| Repeater | A tall antenna receives on one frequency and resends on another | Wide-area coverage |
| Simplex node | A radio on one frequency joined to the internet by a small computer | Reaching other nodes far away |
| Linked repeaters | Several repeaters joined so a call is heard on all of them | Regional nets |
| Hotspot | A tiny personal digital radio linked to the internet | Digital voice at home (ham) |
What a simplex node is made of
- A radio set to one simplex frequency
- An interface that connects the radio audio to a small computer such as a Raspberry Pi
- Node software, plus an internet connection
- An antenna, ideally outdoors and high
See the Build and fix a node page for parts and troubleshooting.
Simplex versus repeater
- Simplex needs no tower and no tone, but range is only as far as your two antennas can see.
- A repeater multiplies range but depends on one site and one owner.
- A node gives simplex users a bridge to far-away places through the internet.
Staying legal
- Ham nodes need a ham license; GMRS stations need a GMRS license.
- Always ask the owner of a repeater or node before you use it.
- Rules about linking GMRS stations over the internet can be unclear, so read the current Part 95 text and ask the FCC if unsure.
- Identify with your call sign as required.
General information, not legal advice. Check the current FCC rules before you transmit.
