Remote Keyer Interface for Flex 6000 Series

What is this? 

RemoteKeyerInterface (RKI) is a simple program that makes it possible to use paddles or a straight key at your operating location to send CW through a remote Flex‑6000 transceiver.

With a CW keyer or a straight‑key connected through a serial port to the Windows PC where RKI is installed, you can send CW on a Flex‑6000 transceiver located in another room at your QTH, or on a Flex‑6000 transceiver at a remote location that is hundreds, or thousands, of miles away.

The serial port that your keyer or straight key connects to may be a built-in port on the computer, or a serial port on a “USB‑to‑Serial” adapter.

Almost any CW keyer will work with RKI, but the built-in side‑tone and ‘PTT’ output of the K1EL WinKeyer USB make this keyer an optimal choice for working with RKI.

For side‑tone, you can use either the built-in side‑tone generated by your CW keyer, or the optional side‑tone generated on your Windows PC by RKI.

A high-resolution .pdf copy of the "Operating Position" diagram shown above is available in the "files" area of this site:

How does it work?
Your CW keyer, or straight‑key, is connected to the PC where RKI is installed, through a RS‑232 serial port. This will normally be the computer where you have installed SmartSDR. The serial port can be a built-in serial port on your computer, or a serial port on a “USB‑to‑Serial” adaptor. A very simple “no-solder” circuit connects the ‘KEY’ and ‘PTT’ (if provided) outputs of your keyer to the 9-pin connector that plugs into the serial port.

When RKI is running, the “Connect” button in the RKI control panel launches a copy of the SmartSDR “Choose Radio” dialog box. You connect the RKI program directly to your Flex‑6000 transceiver through this “Choose Radio” dialog box.

RKI uses the same FlexRadio “Choose Radio” software component as SmartSDR. However, RKI use of this software is completely independent of the SmartSDR use…  RKI does not communicate with, or through, SmartSDR.

In the “Choose Radio” dialog box, you have the choice of connecting to a Flex‑6000 transceiver on a local network, or to a transceiver at a remote location, either via SmartLink or through a VPN connection.

When RKI has been properly configured to recognize the serial port where the CW keyer or straight‑key is connected, and a connection has been established between RKI and a Flex‑6000 transceiver, the dit‑dah output from the keyer or straight‑key is sent to the transceiver, coded with time‑stamp information, so that the transceiver can transmit the CW signal as it has been keyed in by the operator.


Network performance dependencies… 
Decoding and using the time-stamped CW stream, as described above, is a documented feature of the Flex‑6000 transceiver firmware. The FlexRadio ‘Maestro’ control console uses this same functionality to implement remote CW operation. An inherent limitation of this approach is that there is an unavoidable delay between the operator input at the keyer paddles or straight‑key, and the corresponding CW output from the transceiver.

Depending on CW operating speed, this delay may be barely noticeable when the transceiver is on the same wired or WiFi network as the operating position. The delay can become much more apparent, and perhaps variable, when the transceiver is at a more distant location. Network performance, geographic distance, and CW operating speed are interdependent factors that affect the usability of this FlexRadio remote CW solution, regardless of whether you’re using RKI or a Maestro control console to implement remote CW operation. 

How to Download?
The RKI installer is available in the ‘Files’ area of this page, which can be found at this URL:

How to set it up? 
Serial port interface documentation is available as a PDF:


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