“The idea with JS8Call is to take the robustness of FT8 mode and layer on a messaging and network protocol for weak signal communication on HF with a keyboard-to-keyboard interface. JS8Call is heavily inspired by WSJT-X, Fldigi, and FSQCall and would not exist without the hard work and dedication of the many developers in the amateur radio community.”

Frequently asked questions

You’ve got questions, we’ve go the answers. If you cant find the answer to your question please have a read through the documentation. You can always contact us if you still need help.

What is JS8Call?

JS8Call is an experiment to test the feasibility of a digital mode with the robustness of FT8, combined with a messaging and network protocol layer for weak signal communication on HF, using keyboard-to-keyboard style interface. JS8Call is heavily inspired by WSJT-X, Fldigi, and FSQCall and would not exist without the hard work and dedication of the many developers in the amateur radio community.
FT8Call stands on the shoulder of giants…the takeoff angle is better up there.

JS8Call stands on the shoulder of giants…the takeoff angle is better up there.

How can I find out how to use JS8Call?

The best place to start is to read the documentation, it provides you with all the information you will need about JS8Call and its features, the documentation can be found by clicking on this link we encourage all users to please read this.

You can look at our User Guides and Videos that you will find on the Guides Page

And you can also join the groups.io email list.

Do I have to Pay for JS8Call?

JS8Call is Free Software.

It is and will always be free. Free as in beer and free as in speech.

Meaning, you will never have to pay for it, and, you can do with it what you want. It is a derivative of WSJT-X, is open source, and licensed under the GPLv3.

What frequency can I use for JS8Call?
The short answer is that you can use any frequency that allows data/narrow band modes. You can program new frequencies into the settings that will appear in the Frequency Drop Down, you can type the desired frequency into the frequency drop down, or you can manually tune your radio to a new frequency.

From version . 0.5.2 the default “centre of activity” frequencies set up in FT8Call are listed below, but please note as we previously said, these are not set in stone and can easily be changed in your settings, or you can simply manually retune your radio to another frequency if the frequency is in already in use.


1.842Mhz 3.578Mhz 7.078Mhz
10.130Mhz 14.078Mhz 18.104Mhz
21.078Mhz 24.922Mhz 28.078Mhz
What operating system can I run JS8Call on?

JS8Call is compatible with most modern operating systems Windows, MacOS, Linux – desktop and Raspberry Pi versions are available. The windows version has been tested on windows versions 7 to 10, some users have even got it running on Windows XP.

Check out the downloads section for your specific Operating System

Do I need to synchronise my computer's time to use JS8Call?
Yes, your computers clock needs to be within 2 seconds of everyone else. You can sync the clock using a variety of software if you are connected to the internet using the Network Time Protocol (NTP). If you have no access to the internet you can sync your time using an attached GPS or manually if your GPS does not connect to your computer. You copuld also manually sync your time but watching the signals on the waterfall display and setting the time when they begin to transmit,  not the most accurate way of syncing but it might be enough to get you up and running!

if you have internet access you can check how accurate your clock is by going to time.is

Do I need a connection to the internet to use JS8Call?

No you don’t, FT8Call only requires your computer to be connected to your radio.

You will of course need to make sure your computer’s clock is as accurate as possible, and your copy of JS8Call will not be able to report spots to PSKReporter or APRS-IS.

What is the AUTO button for?

JS8Call allows users to send commands to other stations, for example if you want to get a signal report from a station in your hear list you would right click on that station, select the Directed to <CALLSIGN> menu option, then select “? – What is my signal report?” and FT8Call will sent the signal report query to the station eg


if OH8STN has auto enabled his JS8Call will send back the signal report


So if you want to respond to commands from other stations then enable AUTO, or disable it to prevent your station replying.

Whats is the BCN button for?
BCN enables the Beacon. This sends out 2 frames at a time interval which is configurable in settings. The purpose of the Beacon is to let other operators know you are there even if you are not activly calling CQ or already in a QSO.

Whats that "lightning bolt" ⌁ at the end of the message?
This is a special character, its called an ala . It is a symbol to indicate the End of Transmission, the last frame of the message has been transmitted with nothing else to follow. This means you get a visual indicator that the transmission is done and you can begin transmitting a reply.

What are Directed Messages?
There are special directed messages that you can send to stations to have them automatically reply if they have AUTO enabled. They are comprised in the form of [CALLSIGN][COMMAND].


M0IAX? – request signal report from M0IAX

KN4CRD$ – request KN4CRD to tell you what stations he can hear (replies with the top 4 ranked by SNR)

OH8SHN!73 THANKS FOR THE QSO – displays the message in a message box in OH8STN’s FT8Call window


Available commands:


  • ? – What is my SNR?
  • @ – What is your QTH (station location)?
  • & – What is your QTC (station message)?
  • % – What is your station power?
  • $ – What stations are you hearing? (Will transmit the top 4 ranked by SNR)
  • QSO [CALLSIGN]? – Can you communicate directly with CALLSIGN?
    • If the station ACKs, they will send back the SNR and the last time the callsign was heard at their station
  • |message – Please ACK and retransmit the following message
    • The message is retransmitted by the receiving station  verbatim with the addition of “DE [CALLSIGN]” added to the end of the message…meaning you do not need to add it to your message.
  • !message – Please display this message in a alert dialog and ACK if acknowledged
  • #message – Please ACK if you receive this message in its entirety
  • AGN? – Have the station automatically retransmit their last message
  • QTC – Send station message
  • QTH – Send location message
  • GRID – Send a long-form grid locator (to be spotted on a map via PSKReporter & APRS-IS)
  • QSL? – Did you receive my last transmission?
  • QSL – I received your last transmission
  • YES – I confirm your last inquiry
  • NO – I negative confirm your last inquiry
  • HW CPY? – How do you copy?
  • RR – Roger. Received. I copy.
  • FB – Fine Business
  • 73 – I send my Best Regards / End of Contact

How do I call CQ?
Just click on the CQ button. FT8Call will put a CQ message in the message pane, you can type in more text if you want. (NOTE You don’t need to enter your callsign, FT8Call will do that for you before the message is sent).

Then Click Send (The send button will show you how many frames it will send)

How to Download the JS8Call software

Simple, just click the button to go to the downloads page!