VarAC

VarAC: A Game-Changer for Ham Radio Digital Communications

SEEN, after extensive testing, has included VarAC into it's digital software toolbox. VarAC is a digital mode software written by Irad Deutsch (4Z1AC) designed specifically for a robust and efficient way to engage in keyboard-to-keyboard QSOs, file transfers, and emergency communications. Built on the VARA protocol, VarAC has gained popularity for its combination of speed, efficiency, and ease of use. 

SEEN has included this software because of it's excellent features. Here are just a few:

1. Fast and Reliable Digital Communications
VarAC utilizes the VARA HF and VARA FM modem, which provides near-PACTOR-level performance without requiring expensive hardware. Unlike traditional digital modes like FT8, which focus on quick signal reports, VarAC supports conversational QSOs, making it ideal for rag chewing and emergency coordination.

2. Structured and Unstructured Messaging
Operators can send messages in real-time or use VarAC’s store-and-forward messaging system, which allows users to leave messages for offline operators—perfect for emergency communications and tactical operations.

3. Automatic Beacons and Calling Frequencies
VarAC supports automated beacons, letting users announce their presence on a frequency. This makes it easy to find stations without scanning endlessly.

4. File Transfers
One of the standout features is the ability to send small files efficiently, which can be a critical function for emergency communications groups like SEEN.

5. Adaptive Speed and Error Correction
Unlike slower digital modes, VarAC dynamically adjusts its speed based on band conditions, ensuring solid copy even in marginal propagation. This adaptability makes it useful for both casual QSOs and mission-critical communications.

6. Lightweight and User-Friendly Interface
VarAC is relatively simple to install and operate compared to some other digital modes. It has a modern and intuitive user interface, and operators with basic digital mode experience can quickly get up to speed.

Performance in Real-World Scenarios

For Casual Operators
VarAC is excellent for conversational digital contacts, providing a chatroom-like experience over HF and VHF/UHF. The ability to leave messages also makes it appealing for those who can’t always be on the air but still want to engage with others asynchronously.

For EmComm Operators
VarAC is a powerful tool for emergency communications, particularly in scenarios where reliable, low-bandwidth messaging is necessary. It can facilitate critical coordination during disasters, allowing operators to pass messages and small data files when the internet and phone lines fail. It also incorporates an alert system using "triggers" to alert an operator of important messages. These triggers are fully customizable and should be installed into all operators in a group. 

Pros and Cons

✅ Pros:

• High-speed and efficient digital communication

• Reliable error correction and adaptability

• Great for both real-time and store-and-forward messaging

• Easy to set up and use

• Supports file transfers 

• Alert system uses key words to trigger audio and/or visual alerts when key words are received.

❌ Cons:

• Requires a VARA license for full-speed operation (free version is limited) Highly recommend the paid version.

• Not as widely adopted (yet) as other digital modes like JS8Call

• Dependent on propagation conditions for long-range HF contacts

SEEN uses it because:

It is an excellent choice for an advanced digital mode that blends chat, file transfer, and emergency messaging capabilities. Whether for casual QSOs, or emergency communications, VarAC offers a versatile and powerful platform that out performs many traditional digital modes in speed and reliability. Here at SEEN we use it and love it.

For those involved in EmComm, MARS, SHARES, or any preparedness group, VarAC is definitely worth considering as a core tool in their digital communication arsenal.