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What is MOAS II?

MOAS II is an antenna switching and station-control system for operators managing multiple radios, amplifiers, and antenna options. It is built around one core idea: safe, repeatable RF routing without adding operational friction.

The platform is designed to support:

  • deterministic relay switching
  • interlock-first path validation
  • clear operating state visibility
  • remote operation that still respects station safety constraints

Capabilities

MOAS II drives antenna relays and related control lines from a computer over USB (or ethernet/wifi).

It supports up to 64 independently controlled relays. Outputs are arranged in banks of eight, and each bank can be configured as high-side (source) or low-side (sink) switching. That electrical choice is abstracted away from software, so control logic stays consistent.

The system interfaces with transceiver amplifier keying lines and can optionally wire into inhibit lines. This allows coordinated switching that helps prevent hot-switching and enables different routing strategies for transmit and receive paths.

With the server and configuration tooling, MOAS II can manage advanced station layouts, including:

  • multi-stack antenna systems
  • electrically steerable arrays (such as 4-square systems)
  • shared TX/RX antennas
  • triplexer-based combinations
  • single-band and shared amplifier workflows
  • custom inhibit and sequencing rules

This makes it practical to build and operate antenna systems that would be difficult or unrealistic to run safely with manual switching alone.

MOAS Elements

Multi-Platform Server

A server is required to control the hardware switch. The server is what loads the configuration and manages the logic. It is available for most operating systems including Docker. Download it at https://moas.m1dst.co.uk/server/.

MOAS II Master Of Antenna Switching (MOAS) Developed by James Patterson, M1DST and Paul Young, K1XM. Version: v2.0.0

Loading configuration: C:\Users\m1dst\m1dst_COM10.moas Read 1950 lines from configuration file Configuration loaded. MOAS core running. Press Ctrl+C to stop. Switch 1 port COM10 is connected Switch 1 port COM10 is operational

Configuration Tool

It’s possible to build your own configurations manually, but it’s strongly recommended to use the visual editor. The built‑in validation helps prevent errors and makes the process far more reliable. Open it at https://moas.m1dst.co.uk/config.

Switching Hardware

Planned documentation for controller boards, relay modules, wiring strategy, and build notes. Supports connectivity via USB, Ethernet and WiFi.

Multi-Platform Client Apps

Planned desktop/mobile client guides, API examples, and operator workflows.

History

MOAS II was designed by K1XM. A full history of the project including his firmware, server and client tools can be found at https://www.k1xm.org/Antenna_Switch/MOAS_II/index.html

This site and platform build on that foundation with a modern software layer: multi-platform services, web configuration, new hardware and tools.