VarAC to the Max

Last update: 2026-03-13

VarAC has many excellent communication features and capabilities when used correctly.  It takes time to get to know all the features and to use them correctly.  Each operator ultimately has a different way of using VarAC, and VarAC also accommodates that.

•  VarAC Screen - General Layout and Functional Areas - Video

This video provides a general introduction to detail and various functional areas of the VarAC screen layout.

• VarAC Presentation at ZS1STN Power Hour Tech Talk
  This is a YouTube video providing an introduction to and overview of VarAC for the Sandton Amateur Radio Club’s Power Hour Tech Talk on 30th of July 2025

• Using Relay Messages with VarAC - Video, Video 2, Video 3

Terminology used: To relay a VMail message via a relay station is the same as to park a VMail at a relay station.

You park a message at a relay station to enable the recipient to collect the VMail when they are online again, or propagation conditions permit it.  As soon as the BEACON of the recipient station is heard by the RELAY station, the relay station informs the recipient station it has a parked VMail for it which has to be collected.

This is one of the most power features of VarAC, however many new VarAC users seem to struggle with the concept of storing and collecting VMails via Relay stations.

Note, When creating the VMasil you use exactly the same process to compose a standard VMail and one you wish to relay!! However, with a standard VMail you connect to the destination station, whereas when parking a VMail (i.e relaying a VMail)  you connect to the relay station where you will park the VMail. 

From here on the process delivering a normal VMail versus parking a VMail at a relay station differs.  

• Parking a VMail at a relay station

  • You open the VMail folders, and then select the folder containing the VMail message(s) you wish to relay - typically the OUTBOX or the DRAFT folder. .

  • You have to follow this process for each of the messages you wish to relay.  

  • Open the VMail, then you click on the EDIT-button, and then on the UPDATE-button, and then click on the SEND button. 

  • At this time a screen pops up to notify you are not connected to the station your relay message is addressed to – that is quite in order. 

  • Click on the YES-button to send that message to the Relay station. 

  • Repeat this for each messages you wish to relay/park at the Relay station.

  Remain connected to the relay station until it shows that each relayed message was successfully transferred. Only after receiving this acknowledgement it is safe to disconnect.

• Sending a VMail to the intended recipient

  • Connect to their station, QSY to a working channel.  

  • Open your message OUTBOX, click on the EDIT-button, and then on the UPDATE-button, and the message is immediately sent to the station.  

  • WAIT until the "message successfully delivered" message is displayed by the receiving station. 

This video gives a more in-depth understanding of how to use RELAY messages on VarAC

• Parking a relay message - Video

The term Parking a VMail is synonymous with sending a  relayed VMail message.  

The philosophy is to park your VMails at a site which you and the intended recipient can access easily.  

Depending on which antennas  you use, when using an  NVIS antenna on  HF, an ideal relay site would be one which is between 400 and 600 km from both of you.  Under most conditions both of you will then be able to access the relay station.

• Sending a VMail to E-Mail Address - Video

This video gives a short introduction on how to send a VMail to an email address.

• The I’m-Away-Option - Video

This video shows a solution to stations that do not have CAT-control and for automatic QSY when stations connect to it.

If the station you want to connect to cannot auto-QSY (i.e. it does not have CAT-control), if their I’m-Away-Option is enabled this enables the connecting station to send a short VMail or a short message within the remaining permissible time for a QSO on the calling frequency.

In cases where the I'm Away-option is not enabled, the calling station is not informed that the station cannot QSY. The calling station will attempt to QSY, and then eventually VarAC informs you the other station did not QSY with you (i.e. the QSY test fails), and then the CALLING station returns to the CALLING Channel.

If the I’m-Away-Option is enabled, you can immediately commence with sending your VMail when you connect to the station – without wasting time to QSY to a WORKING channel and then returning to the CALLING channel.

• Ping – validating two way communications - Video

This video show how to use A ping to test the link between your station and the specified station. The Ping report gives the SNR for both directions of the link and validates that communications is possible, versus doing a one-way test with a broadcast SNR report.

• VarAC Nets - Using Broadcasts

Click here for the VarAC-Net procedure document URL

Click here for the VarAC Net procedures use by Net-Control

We have been trialing to use of VarAC using the VarAC broadcast messages for digital Nets. The procedures used for the digital nets are loosely based on those used for voice nets, but now for a digital mode using the VarAC broadcast message capability.

In terms of operating procedure, we had the option to use a typical round robin way of managing hand-overs between participants.

However, due to fading and some participants being unable to hear others, or not hearing when it is their turn to participate, we opted for the model where net-control manages all hand-overs. If for any reason one participant cannot hear another, net-control manages the process.

We also used a soft “time-out” for a user to respond with activity, that the next participant is called to send their message. If you have to wait too long for a user to send their message, then users loose interest in the slow moving net.

Some tips:

• Participants need to prepare their messages beforehand. Don’t let other users wait for you to complete your one-finger typing!

• Create message beforehand using a Windows application such as Notepad, and then cut and paste your message from there into VarAC’s text area.

• Alternatively, compile your messages beforehand and save them as DRAFT messages. Then it is just as quickly to send your messages when it is your turn to respond.

Thirty minute video of a VarAC Digital Net done on 2025-07-03, as viewed from a net-controllers perspective.

• VarAC Nets - Using Broadcasts

• VarAC Net Control

• Comparison of various Digital Modes

This document compares the main features of VarAC with Winlink and JS8Call, specifically with the requirements of emergency communications in mind.

• Using the 2300 Hz bandwidth option with VarAC

Take cognizance of the fact that when using VarAC with the 2300 Hz bandwidth option you should never do so on the standard calling frequency. Edit the frequency file and specify an alternate calling frequency which does not overlap with the existing calling frequency.

When you use 2300 Hz it immediately clobbers up to five standard 500 Hz working slots !! Hence the request that you never use the standard calling frequencies, nor the standard working slots when using the 2300 Hz bandwidth option.

• VarAC Relay Message Exercise - Video

The diagram below shows the process flow used for forwarding of a VMail required by this exercise.

The exercise coordinator (EC) parked a VMail message for Participant 1 at Relay 1.

When Participant 1’s station beacon is heard by Relay 1 he is informed of a parked VMail at Relay 1. Participant 1 then collects the message, and as per the instructions contained in the message, addresses a VMail message to Participant 2 and parks it at Relay 2.

When Participant 2’s beacon is received by Relay 2, he is informed that there is a parked VMail for him at Relay 2.

Participant 2 collects the VMail from Relay 2 and then sends the VMail message as an email via a VarAC Email gateway of their choice to the email address contained in the message instructions.

The process concludes with the VMail being received as an email at the specified email account.

The above process is shown in this video.

The eagle eyed folk, take note of the connection timer in the video, displayed just above where the callsign on the station callsign you’re connected to is displayed. There you will see the duration the downloads had taken in doing the video.

• Configuring VARA-FM for use with VarAC - Video

This is a separate document and video on how to configure VARA-FM for use with VarAC

• VarAC Exercises

  • Net Control Exercise

Instead of using VMails, use VarAC's broadcast capabilities to permit multiple users to simultaneously receive and respond to broadcast messages.

• • Relay Message Exercise

    • The diagram below shows the process flow.

    • The first participant  collects a VMail from a relay station, then sends the response to that VMail via a different relay station. 

    • The second participant collects the relayed message and responds to the instructions contained in the relayed VMail and then sends a response as an email to the exercise coordinator.

• • Message Relay & E-Mail Exercise

  • VarAC Exercise 2

  • Digital Mode Nets

VarAC’s VMail messaging focus primarily on point to point connections, whereas the broadcast messages permit one-to-many messaging.

To encourage new users to participate and interact with each other we considered creating digital node nets – where participants use broadcast messages.

This resulted in to main net procedures developing, the one being a round-robin net, where net-control announces the round-robin sequence and then hands over to each participant. Each participant then hands over to the next, until control returns to the net-control.

Since propagation in winter is very variable during the times we were having the nets (initially at 18h30 local time, and later moved to 20h00 local time) and often stations would not be able to have reliable broadcast messages between each other, we opted for a net where net-control manages handing over to individual stations. If a station did not hear a broadcast, then net-control would hand over to the next station. Or as new participants checked in late, they could be accommodated easily by net-control.

Reference Documents:

• Net-control template document

• Exercise procedure document

• VarAC versus Winlink email capabilities

• Here is an online comparison of VarAC's email features compared to Winlink and more info associated with the VarAC Email capability

• Here is a different comparison of VarAC vs Winlink's operating philosophies

• Setting up the VarAC Email Gateway

Rather than struggling doing it your way, read this VarAC Email Gatway reference page

Interfacing your transceiver with the digital modes application is often where many hams get stuck when doing this for the first time.

Click on the drop down list on the top of the screen and select the appropriate option from there.

• About

My name is Alister ZS2OK and we live in St Francis Bay, in the Eastern Cape, South Africa.  At this time I only use digital modes - using VarAC and Winlink.

VarAC is developed by Irad 4Z1AC, while VARA is developed by 4Z1AC.José.  

We have been using VarAC since the second year of its inception with the specific focus of using VarAC for emergency communications.

With respect to the frequency schedule used, the focus is on using frequencies that permit connectivity day or night for both national coverage and regional communications.