CTR2-Mini was designed to be a simple, small radio controller that anybody could easily build and deploy in their station. Multiple operational options are available when linking two Minis via WiFi or Bluetooth LE that just aren’t available any other way.

This post will describe each Link option so you have an idea of what’s available.

Basic Sync

Basic Sync mode allows you to link two Minis and synchronize several functions. Each Mini and its radio operate autonomously but you can easily push or pull the frequency and mode from one Mini/radio to the other Mini/radio. This allows you to use one radio as your operating radio and the other radio as a search radio during a contest, or when you just want to watch another band for an opening.

Basic + Frequency Sync

Basic + Frequency Sync mode provides the same features as Basic Sync mode plus it synchronizes the frequencies of both radios. This gives you full receiver diversity since each receiver listens to the same frequency on a different antenna. Just use the radio/antenna that works best for the station you’re working. In this mode, tuning either Mini or either radio changes the frequency both Minis and radios.

This mode provides a Rx-B Zero Beat adjustment on Mini-B’s Link menu so you can zero out any frequency differences between the two receivers.

Basic + Tracking Sync

This mode is similar to the Basic + Frequency Sync mode with the exception that the two Minis and their radios are tuned to different frequencies. These frequencies are usually on different bands. In this mode, tuning either Mini or its radio tunes the other Mini and its radio the same amount. The frequency offset is determined when you first establish the link. For instance, if Mini-A (and its radio) is tuned to 7.000 MHz and Mini-B (and its radio) is tuned to 14.000 MHz when you connect the link, tuning Mini-A to 7.050 MHz tunes its radio to 7.050 MHz and it tunes Mini-B and its radio to 14.050 MHz.

This allows you to work two bands at the same time during a contest (or even when just casually operating). As you tune one band you automatically tune the other band. Radio-A is connected to your headphone’s left speaker and Radio-B is connected to the right speaker. When you find a station calling CQ just enable the Tx on that Mini and answer their call.

Remote Control

This mode is more conventional than the first three modes. In this mode, Mini-B is connected to the local radio and Mini-A is linked to Mini-B via WiFi as a remote controller. This mode allows Mini-A to control your radio remotely from any Internet connection. Audio to and from the radio to the remote location can be handled by an audio server such as Sonobus or Mumble. Direct CW keying is not currently supported in this mode.