Call-out
- SafecomLink
- Dec 11, 2025
- 2 min read
Updated: Dec 29, 2025
The Call-out feature is the fundamental function in SafecomLink for instantaneously initiating a real-time, peer-to-peer chat (Live Link). It serves as a network-wide announcement that your station is actively seeking connection.
The Slot Mechanism for Call-out
The Call-out mechanism leverages a Slot-based system to manage frequency congestion on the main Calling Frequency (CF).
Slot Definition and Encoding: Slots are defined as multiple frequencies around the main Calling frequency, typically separated by 750 Hz steps. When a station initiates a Call-out, the system encodes the chosen Slot ID (the specific frequency offset) directly into the transmission.
Automatic frequency change: Immediately after the Call-out is sent on the main CF, the calling station performs an Automatic Frequency Change to the selected Slot, where it awaits an incoming link request. This process clears the main channel quickly, dramatically reducing connection time to approximately 10–15 seconds.
Frequency Discipline: Operators must utilize the Slot Sniffer tool to check that their chosen Slot is clear before transmitting their Call-out. The use of this mechanism is mandatory when operating on official HF calling frequencies.
Network Visibility: Last Heard Call-outs
The value of the Call-out is reflected in the instantaneous network feedback provided through the "Last heard Call-outs" list.
Real-time Display: All monitoring stations decode these transmissions, displaying them instantly on the screen along with the callsign, the Signal-to-Noise Ratio (SNR), and the critical Slot ID where the calling station is waiting.
Direct Connection: This allows an operator to respond to an active Call-out by simply double-clicking the callsign in the list, triggering an immediate and automatic frequency change to the corresponding Slot ID to establish the Live Link.
Enhanced Information: Users can also send special Call-outs which include their Grid Locator or any other additional dala. These richer announcements also appear on the last heard list, giving responders quick geographic/additional context.
Package Differentiation
Sending Capability: The capability to send Call-outs (to initiate a Live Link/Chat) is supported by the Pro, and Enterprise SafecomLink packages.
Receiving Capability: Users on all types of packages can successfully receive and respond to Call-outs (Live Link initiation attempts).
The Call-out feature is essential for initiating fast, organized communications by efficiently moving conversations off the congested Calling Frequency using a Slot-based change-frequency mechanism. All stations monitoring the frequency gain immediate situational awareness via the "Last heard Call-outs" list, enabling precise targeting of stations and rapid link establishment. This design ensures fluid radio resource management, reducing link times significantly.
