*Question E2C09:
What type of equipment is commonly used to implement an amateur radio mesh network?*  

*Correct Answer is  C: A wireless router running custom firmware*  

### AI Response: (may contain errors)  

To understand the correct answer for implementing an amateur radio mesh network, let's break down the options:

### Correct Answer: C - A wireless router running custom firmware

- **Explanation**: 
  - A mesh network is designed to allow multiple nodes to communicate with each other efficiently. 
  - Wireless routers with custom firmware (like OpenWRT or DD-WRT) can be configured to create a mesh network, allowing for dynamic routing and better coverage.
  - These routers can connect to each other wirelessly, forming a robust network that can extend over large areas, which is ideal for amateur radio applications.

### Why the Other Choices are Incorrect:

- **A: A 2-meter VHF transceiver with a 1,200-baud modem**  
  - While this setup can facilitate communication, it is not typically used for mesh networking. 
  - VHF transceivers are more suited for point-to-point communication rather than the multi-node connectivity required in a mesh network.

- **B: A computer running EchoLink to provide interface from the radio to the internet**  
  - EchoLink is primarily used for linking amateur radio stations over the internet, not for creating a mesh network. 
  - It connects individual stations rather than forming a network of interconnected nodes.

- **D: A 440 MHz transceiver with a 9,600-baud modem**  
  - Similar to option A, this setup is more focused on specific communication links rather than establishing a mesh network. 
  - While it can facilitate digital communication, it does not inherently support the dynamic routing and node interconnectivity that a mesh network requires.

### Summary:
- A wireless router with custom firmware is the best choice for creating a mesh network due to its ability to manage multiple connections and routes dynamically.
- The other options are more suited for traditional communication methods rather than the flexible, interconnected structure of a mesh network. 

This understanding is crucial for the Extra Class exam, as it highlights the importance of network design in amateur radio applications.