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HaliKey is a small USB device that connects morse code paddles, or a physical PTT switch, to a computer.  This allows you to use physical controls when operating your radio remotely.

SmartSDR for MacOS supports both CW and PTT, but SmartSDR for Windows only supports PTT.

In stock (can be backordered)

USB Adapter

Allows HaliKey to be inserted directly into a computer or hub like a conventional dongle. See below about USB adapter availability.

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HaliKey is a small USB device that connects morse code paddles (Mac only), or a physical PTT switch (Mac or Windows) to a computer, and allows you to use physical controls when operating your Flex radio remotely.

HaliKey was designed to work with Flex Radio Systems™ SmartSDR software, for both MacOS (PTT and CW) and Windows (PTT only).  HaliKey also works in Linux for any software that uses CTS and/or DSR/DCD signals from a serial port to trigger an event.

Weight 0.02 lbs

Tip to CTS, Dit
Ring to DCD, Dah
Sleeve to Ground


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HaliKey User Guide:

All Halibut Electronics documentation can be found at:

Frequently Asked Questions

Q: Why does HaliKey only do CW on MacOS, and not Windows?

A: SmartSDR for Windows and SmartSDR for MacOS are written by different developers: Windows written by Flex Radio, and MacOS written my Marcus Roskosch.  They have different feature sets.  As of 2024-03-15, SmartSDR for MacOS includes a CW Keyer, but SmartSDR for Windows does not.

All HaliKey does is convert left and right paddles (or straight key, or PTT) switch closures, to CTS and DSR/DCD (both) signals on a serial port.  It’s up to the software to decide what to do with those signals.  All SmartSDR for Windows knows what to do with those signals is to trigger PTT.  SmartSDR for MacOS will use them as PTT while in voice modes, or iambic paddles while in CW mode.  Full details how to configure both applications can be found in the HaliKey User Guide.

It is possible to use a 3rd-party application in Windows to do CW keying.  Remote Keyer Interface (RKI) is one such program that is ALMOST there.  As of 2024-03-15, RKI v1.0.5: 1) has an iambic keyer built-in for use with the keyboard, and 2) can trigger a straight-key from CTS on the serial port.  All that needs to happen is connect those two: take events from the serial port, and trigger the existing keyer functions.  However, the current developer of RKI is uninterested in continuing development.  Some in the community are trying to get him to release the code into open source to let us continue development.  Assuming we can make that happen, then adding support for HaliKey to RKI should be simple.

This entry was written on 2024-03-15.  If any of the above information has changed and I (N6MTS) haven’t updated this, please Contact Us to poke me to update this FAQ.  Thank you. 🙂