FlexRadio (SmartSDR)

Best for: FlexRadio 6000/8000 series running SmartSDR.

POTACAT connects to SmartSDR’s built-in CAT server over TCP. No additional software or cables needed.

1. In SmartSDR, make sure the CAT server is enabled (SmartSDR CAT settings)
2. Add a new rig → select FlexRadio (SmartSDR)
3. Choose your slice (A, B, C, or D)
4. Save

SmartSDR exposes Kenwood-compatible CAT on TCP ports 5002–5005:

If SmartSDR is on a different computer, use IP Radio (TCP CAT) instead with the Flex’s IP address.

Tip: Start order matters. If spot clicks or QSY start erroring, close both apps and reopen SmartSDR first, then POTACAT.

Direct connection — SmartSDR doesn’t have to stay open

POTACAT also binds directly to the radio’s own API (TCP port 4992), so SmartSDR isn’t required to keep operating. If SmartSDR closes, POTACAT re-binds directly to the Flex within a couple of seconds, and hands back when SmartSDR reopens. CW is fully supported on this path, including keying through a WinKeyer.

The “independent slice” gotcha

If Run independent slice is checked in the rig settings, clicking spots will not move your SmartSDR slice — POTACAT works its own slice instead, and on some radios that means a brand-new slice opens (e.g. slice C on a 6600). If spots show up but the radio never QSYs, uncheck it.

Digital and remote audio need DAX

ECHOCAT and JTCAT audio go through SmartDAX, not the CAT connection:

1. DAX must be running.
2. In SmartSDR, assign the slice flag to a DAX channel.
3. The SmartDAX window should show a blue indicator next to that slice.
4. In POTACAT, select the DAX Audio RX/TX devices as the rig’s audio in/out.

There’s also a setting to pin your TX to a chosen DAX channel, so transmit audio never silently loses its DAX assignment.

JTCAT / FT8

JTCAT talks to the SmartSDR API host on TCP port 4992. Make sure POTACAT has the Flex’s IP address configured — it’s the same address used for SmartSDR panadapter spots — and that your firewall allows POTACAT to reach the radio. A firewall rule that only allows SmartSDR.exe isn’t enough.

Connection troubleshooting

If POTACAT suddenly can’t connect (often after an upgrade), test from PowerShell:

Test-NetConnection <radio-ip> -Port 4992

• True, but POTACAT still fails → your firewall allows SmartSDR.exe but not POTACAT.exe, or the radio has hit its multi-client limit (default: 2 GUI clients). Close an extra client and retry.
• False → your PC is on the wrong subnet from the radio.

See also

• SmartSDR Panadapter Spots — push POTA/SOTA/DX spots onto your panadapter, including on Maestro and SmartSDR for iOS.