This post last revised: 01/21/2018
This post shows the settings I use with my IC-7300 for digital modes over the USB connection from the 7300 to a Windows computer. (e.g., BPSK31 using Ham Radio Deluxe Digital Master 780, fldigi, WSJT-X) These settings seem to work equally well with most digital modes, and digital mode software. These settings might be different for DXLab Commander and Ham Radio Deluxe. See my other posts that address the specifics of DXLab Commander and HRD.
It is easiest to connect the IC-7300 using a single USB cable. Be sure that you first download and install the Icom USB driver before connecting your 7300 to the Windows computer the very first time. Windows will try to auto-install its own driver if you simply plugin the USB cable from the 7300 to the computer, and that one doesn’t work with the Icom USB interface.
In this article, use the context to differentiate USB (PC Universal Serial Bus) vs. USB (Upper Side Band).
Set UP your IC-7300 for Digital Modes
Open the Settings -> Connectors menu. There are 4 important settings.
- USB AF Output Level – 40%. This affects the Audio Level heard by your computer. Depending on your software, you may want to change this. For WSJT-X, this value affects the
- USB MOD Level – 40%. Set this so that you get a minimal ALC meter reading when transmitting. This should assure you have a clean output signal. This value can vary depending on your software. The value is also related to your output power. See the output power description below.
- DATA OFF MOD – Mic. This option tells your IC-7300 which audio input source (modulation) to use when the DATA mode is OFF. This would normally be your microphone (MIC) when in regular USB/LSB modes. Note that the versions of the 7300 firmware after late 2017 have added an option for this setting called MIC, ACC. This new option was technically unnecessary, but many people were confused by the DATA OFF and DATA (ON) options, and were getting no audio when switching between Digital and Microphone modes. The MIC setting is really “correct”.
- DATA MOD – USB. Use the USB connector to get your audio from your computer when in data mode (USB-D).
- CI-V – These settings relate to the USB control interface and are controlled by the setup of your digital software. They are related to the ICOM USB port driver you must install for Windows, the serial COM port number that ends up being the one used for your particular PC, and the baud rate you decide to use. These are usually described in some detail for each digital control program you use, and can be set up so that all your software will talk to your IC-7300.
Note: the CI-V USB Port setting should be set to “Link to [REMOTE]”. This setting seems to be required for most software programs using the CI-V function. A side effect of this is the the CI-V USB Baud Rate will be limited to 19200. You want the fastest Baud rate possible.
Use USB-D Mode
Now, when using a digital mode, you should use the USB-D mode. (Click the Mode label in the upper left, select USB and select DATA.) The USB-D mode is needed so that the DATA MOD option works as expected. It also lets you define a custom filter for BPSK31.
You can set the Filters (1-3) for each mode (USB, USB-D, AM, etc.). The default for the Data modes is very narrow, and this doesn’t work well for BPSK31. So change the USB-D Filter 1 by long-pressing the FIL1 button on the screen, and set the BW to 3.0K or wider. Alternatively, if you use RTTY or other narrower modes, you can use FIL2 or FIL3 instead for BPSK31.
Other Important Settings
- No compression – this should be automatically disabled when you are in USB-D mode. You can check on the FUNCTION screen – COMP should be disabled.
- No Notch Filter – press the NOTCH button until it is OFF
- NB (noise blanker) and NR (noise reduction) both OFF.
Reduce Your Transmit Power
Don’t forget to reduce your RF output power when on digital modes. The effective output power is determined by a combination of three settings:
- The output volume of your computer audio out (microphone). Ultimately, this is the best way to control your RF output power. Your digital mode software should have an option or on-screen setting to change this level. For example, WSJT-X has a vertical slider on the lower right labelled “Pwr”. This controls your output power by controlling the audio level delivered to the IC-7300. There are similar settings for fldigi.
- If you are controlling RF output power by using the audio level on the computer, then you should be able to pick a usable constant level for USB MOD level. Around 40% seems to work well.
- You can also leave the RF power of the IC-7000 (set from the MULTI physical knob) to 100%. If you don’t have easy RF power control from the digital software, you can instead simply use the MULTI knob to set your RF power to 30%, which will be about 30 watts.
Note that you will likely want to operate with the meter set to S/Power Out to monitor your RF output power. Remember, you don’t need more than about 30 watts to make contacts, and many people like to run with even less power.
Save Your Settings
Presumably, you will used your 7300 for other operating modes. The settings described for digital modes are not optimal for SSB or CW. Fortunately, you can save all your settings in a named file on the SD card. It then becomes a simple matter to load your settings for different modes.
To save, use Menu -> Set -> SD Card -> Save Setting -> <>. Don’t use the default name – create an explanatory name for your settings file – Digital Modes, USB, etc.
To restore, use Menu -> Set SD Card -> Load Setting. Then pick the settings file for the appropriate mode.
More Details on Power and ALC Control
There are other tutorials on the web about controlling your digital mode output power. One good one is found at: The N7XGR Audio and Transmit Settings Tutorial