FT8 FT4 PSK31 PSK63 RTTY

Stations, not messages.

Costas is a free digital-modes program for Windows. It decodes FT8 and FT4 with the same decoder as WSJT-X, then shows you one line per station: who you still need, who is free to call, and who can hear you.

Download for Windows Read the manual

Latest release · Windows 10 or 11, 64-bit · Free, open source (GPLv3)

Costas during a contact: a strip shows each message sent and received, with the list of stations to call next underneath

It tells you who to call

Every station you hear gets one line, not a scroll of decodes. Next in line puts the ones you need on top: a new country first, then a new band, grid or call, worked out from your log and your QRZ logbook. Stations you have already worked drop into Repeats, with when you last worked them.

The Operate screen

One click runs the contact

Click Call or press Enter. Costas sends the standard exchange, follows the other station's replies and logs the contact when it completes, in the same slot timing you are used to. A strip along the top shows every message, so you always know where the contact stands. Click Call on a DXpedition Fox and it is worked the Hound way automatically.

Making contacts

A contact on the air, with the transmitted message highlighted on the progress strip

It knows who can hear you

Spots from PSK Reporter and the Reverse Beacon Network show, station by station, whether they (or someone near them) are hearing your signal, and rate your chance of completing as Good, Fair or Long shot. A map centred on your grid shows who you hear and who hears you.

Maps and who hears you

A globe centred on the operator, with dots for stations heard and stations hearing you

PSK31, PSK63 and RTTY on the same screen

Pick a keyboard mode from the same menu as FT8. Click a trace on the waterfall to read it, type in the line at the bottom, and send your name, QTH and 73 from F-key macros. Callsigns in the text land in the station list just like FT8 decodes. Nothing goes out until you press a key.

PSK31, PSK63 and RTTY

PSK31 on the Operate screen, with received text and the typing line

Operate from the couch

Costas serves a remote page on your home network. Open it on a phone or tablet to call, answer, change band and halt transmit while the radio stays in the shack. Need the desk back? Mini mode shrinks Costas to a strip that stays on top of your other windows.

Operating from a phone

The phone remote during a contact, with a large Halt TX button

Also in the box

Logging: A local log with ADIF import and export, sent to QRZ, LoTW (through TQSL) and eQSL as you go, with confirmations synced back.
Awards: DXCC, WAS, WAZ and VUCC progress from your own log, and the hours each needed country is usually heard.
Hunt list: Countries, calls, states or grids you are after, with an alert when one shows up on any band. Alerts never transmit.
Transmit level: Audio level sets itself per band from your radio's ALC, with live power, ALC and SWR meters while you transmit.
Radio control: Hamlib, FLRig or network rigctld. Costas follows your radio when you change band on the front panel.
Other programs: Speaks the WSJT-X UDP protocol, so GridTracker, JTAlert and your logger keep working.

Costas never transmits on its own, never changes a message without telling you, and never shows made-up data. With no radio set up, it receives nothing and says so.

Download

Everything is in the installer, including the jt9 decoder and Hamlib. You do not need WSJT-X. Costas installs for your user only and updates itself.

Windows may say it protected your PC: choose More info, then Run anyway. Why, and how to check the download.

Windows 10 or 11, 64-bit · latest Download installer Linux preview x64 · receive only for now Download .tar.gz

Then follow the six-step setup: station, radio, audio, a transmit test, clock and QRZ. Use low power or a dummy load for your first transmissions.

Costas is free and always will be. If it has put a few new countries in your log, you can help keep it going.

Support Costas