QT60 PRO & QT80 Data-mode Operation Guide

Your Radioddity QT60 PRO or QT80 can support digital/data mode operation (FT8, SSTV, RTTY, etc.) using the built-in VOX modes, without the need for external interfaces. This is a DIY option, and the following information is provided to assist with the creation of a cable that will provide the necessary connections; between a computer running digital/data mode software and the radio.

There are not many parts needed to get our own data-cable prepared.
- For the connection to the Radioddity QT60 PRO you will need a “RJ45 terminal adapter” that does make all 8 pins available on screw terminals. We don´t sell those, but you can find them here: http://www.aliexpress.com
- For the connection to your PC, you will either need a shielded stereo audio-cable with 3.5mm TRS plugs on both ends or two shielded open end stereo audio cables with 3.5mm TRS plug.
- If your PC does not have a built-in sound-card you will also need a USB soundcard with 3.5mm TRS sockets for MIC-in and Audio-out.

The following example is the most basic form of the cable that can be built. The cable connects between a PC soundcard or an external USB soundcard and the Radioddity QT60 PRO front Microphone connector. This provides all the necessary connections for VOX based digital/data mode operation. The input and output signals will appear on the LEFT channels of the PC soundcard. The required connections are as follows:

- Pin 5 is the ground signal which needs to be connected to both ground connections (audio-in and audio-out of the PC).
- RJ45 Pin 6 is the Radioddity QT60 PRO input signal which needs to be connected to the computer audio-out signal (speaker-out).
- RJ45 Pin 8 is the Radioddity QT60 PRO output signal which needs to be connected to the computer audio-in signal (microphone-in). The resulting electrical connections of your cable should look as follows:

The wires shown in black color represent the cable shields as well.

The following Radioddity QT60 PRO MENU settings are required/recommended to enable VOX based TX and RX via the Radioddity QT60 PRO front microphone socket. To enter the MENU long press the [MENU] key for 2 seconds and use the channel selector knob to navigate to the required parameter. With careful adjustment of the Radioddity QT60 PRO settings and your PC software settings, good performance can be achieved.

- Menu 01: MIC = Set “Mic Gain” to a low level, adjust as needed.
- Menu 02: MICP = DY
- Menu 03: VPATH = BOTH or MIC
- Menu 22: VOXL = A “VOX Level” of 2 or 3 is recommended, adjust as needed. Can also be set to “OFF”
- Menu 23: VOXT = 1 or 2 is recommended, adjust “VOX delay time” as needed.
- Menu 24: V-SPK = ON (allows VOX to enable PTT when there is open squelch / RX audio)

The following recommendations will assist in achieving the best results:

- Always use LOW RF POWER for digital/data modes. Many of these modes are high duty cycle TX, and are very efficient only requiring low power for excellent results. High power is not required and will result in higher heat which should be avoided.

- Isolation: The DIY cable described in this document is shielded for good results when your PC soundcard levels, and radio are set correctly. “Isolation transformers” may be added to the cable if required to avoid ground loops or interference/noise. The use of clip-on ferrites can also assist with noise or feedback issues, if they occur.

- Levels: Check the signal levels to ensure they match the requirements of your PC interfaces and radio equipment. Always start at a low volume/gain levels (Menu 01) and increase gradually as required. Adjust your PC soundcard settings and radio MIC Gain (Menu 01), VOX-L (Menu 22) and VOX-T (Menu 23) to ensure audio is properly transmitted and received. Be aware that any sounds played by your PC might be transmitted with VOX, so always ensure other sound sources are disabled before enabling VOX (Menu 24).

- Testing: After making connections, test the setup with your digital mode software. Most software will contain a “VOX PTT” option that should be selected.

There are not many parts needed to get our own data-cable prepared.

- For the connection to the Radioddity QT80 you will need a 6-pin GX16-A6P plug, often called “aviation plug”.
- For the connection to your PC, you will either need a shielded stereo audio-cable with 3.5mm TRS plugs on both ends or two shielded open end stereo audio cables with 3.5mm TRS plug.
- If your PC does not have a built-in sound-card you will also need a USB soundcard with 3.5mm TRS sockets for MIC-in and Audio-out.

The following example is the most basic form of the cable that can be built. The cable connects between a PC soundcard or an external USB soundcard and the Radioddity QT80 front Microphone connector. This provides all the necessary connections for VOX based digital/data mode operation. The input and output signals will appear on the LEFT channels of the PC soundcard.

The required connections are as follows:

Pins as seen when looking onto the 6-pin socket of the Radioddity QT80

- Pin 1 is the Radioddity QT80 input signal which needs to be connected to the computer audio-out signal (speaker-out).
- Pin 2 is the Radioddity QT80 output signal which needs to be connected to the computer audio-in signal (microphone-in).
- Pin 5 is the ground signal which needs to be connected to both ground connections (audio-in and audio-out of the PC). The resulting electrical connections of your cable should look as follows:

The wires shown in black color represent the cable shields as well.

The following Radioddity QT80 MENU settings are required/recommended to enable VOX based TX and RX via the Radioddity QT80 front microphone socket. To enter the MENU long press the [FUNC] key and use the large channel selector knob to navigate to the required parameter. With careful adjustment of the Radioddity QT80 settings and your PC software settings, good performance can be achieved.
- Menu 04: MIC.GAIN = Set to a low level, adjust as needed.
- Menu 05: MIC.TYPE = DYNA
- Menu 07: VOL.PATH = BOTH or MIC.JACK
- Menu 24: VOX = ON (note: during PTT you can also press the FUNC key to turn VOX ON/OFF)
- Menu 25: VOX-L = 2 or 3 is recommended, adjust the VOX level as needed.
- Menu 26: VOX-T = 1 or 2 is recommended, adjust VOX delay time as needed.
- Menu 27: VOX.SPK = ON (allows VOX to enable PTT when there is open squelch / RX audio)

The following recommendations will assist in achieving the best results:

Always use LOW RF POWER for digital/data modes. Many of these modes are high duty cycle TX, and are very efficient only requiring low power for excellent results. High power is not required and will result in higher heat which should be avoided.

Isolation: The DIY cable described in this document is shielded for good results when your PC soundcard levels, and radio are set correctly. “Isolation transformers” may be added to the cable if required to avoid ground loops or interference/noise. The use of clip-on ferrites can also assist with noise or feedback issues, if they occur.

Levels: Check the signal levels to ensure they match the requirements of your PC interfaces and radio equipment. Always start at a low volume/gain levels and increase gradually as required. Adjust your PC soundcard settings and radio MIC.GAIN,VOX-Land VOX-T to ensure audio is properly transmitted and received. Be aware that any sounds played by your PC might be transmitted with VOX, so always ensure other sound sources are disabled before enabling VOX (VOX is enabledwithMenu24:VOX=ON).

Testing: After making connections, test the setup with your digital mode software. Most software will contain a “VOX PTT” option that should be selected.

Please note that you can find all firmware, software and user manuals in the support section of our official Radioddity website by following these steps:
radioddity.com → Support → Radioddity → QT60 PRO OR QT80

As soon as a new file is available (e.g., firmware updates, updated manuals or other items), these files will be published in our support area.