The Yaesu FT-DX10 features a high-performance Hybrid SDR receiver. To get the most out of VARA HF’s wideband modes, the radio’s internal DSP filters and USB audio routing must be configured to stay “wide and flat.”

1. Radio Settings (Yaesu FT-DX10)

First, ensure your radio is in DATA-U mode.

The FT-DX10 uses a “Radio Configuration” menu. For the most reliable results, verify these specific menu settings (Press MENU > OPERATION SETTING > COMMUNICATIONS):

• USB OUT LEVEL: 50 (Baseline for RX audio to PC)
• USB IN LEVEL: 50 (Baseline for TX audio from PC)
• CAT RATE: 38400 bps
• CAT TIME OUT TIMER: 10 msec
• USB CAT RTS: OFF (We use software CAT PTT instead)

Crucial Audio Routing (Menu > OPERATION SETTING > CH GEN):

• DATA MODE: OTHERS
• OTHER DISP (SSB): 0 Hz
• OTHER SHIFT (SSB): 0 Hz
• DATA LCUT FREQ: OFF (Prevents clipping VARA’s low tones)
• DATA HCUT FREQ: OFF (Ensures full 3000 Hz bandwidth)

2. PC Soundcard Settings

The FT-DX10 appears as a “USB Audio Codec.”

• Playback: Speakers (USB Audio Codec)
• Recording: Microphone (USB Audio Codec)
• RX Calibration: Open the VARA HF modem window. With the radio tuned to a quiet frequency (static only), adjust the Windows Microphone “USB Audio Codec” level until the VARA VU meter is in the green (12 o’clock position).

3. Winlink Express Radio Setup

In the Winlink VARA HF session, go to Settings > Radio Setup.

• Radio Model: Yaesu FT-DX10
• Radio Control Port: Select the Enhanced COM Port (Check Device Manager; the Enhanced port handles CAT commands)
• Baud Rate: 38400
• PTT Port: Yaesu FT-DX10 (Select the radio model from the dropdown to enable CAT PTT)
• Enable RTS: Unchecked
• Enable DTR: Unchecked

Why CAT PTT? Using the radio model as the PTT port sends a digital “TX ON” command via the existing USB-Serial data stream. This is significantly more reliable than toggling hardware pins (RTS/DTR), which can often be interrupted by Windows system sounds or driver glitches.

4. Transmit Audio & ALC (Drive Level)

To achieve maximum throughput, your signal must be “clean.”

1. Set the FT-DX10 meter to ALC mode.
2. Ensure AMC (Automatic Microphone Control) is OFF in the radio menu, as it can interfere with digital waveforms.
3. Click Red Tune in VARA HF.
4. Adjust the Drive Level slider in VARA.
5. The Goal: Monitor the ALC meter on the radio. It should show zero deflection or just a tiny flicker at the very bottom of the scale. If the ALC bar moves into the middle or high range, your signal is distorted and Winlink gateways will struggle to decode it.

Troubleshooting: “The Busy Lamp”

If your FT-DX10 shows a green “Busy” light but VARA isn’t showing a signal:

• Check the SQL (Squelch) knob. For VARA HF, the squelch must be fully open (counter-clockwise).
• Ensure the WIDTH and SHIFT knobs are centered. If the IF filter is shifted, you may be cutting off the edges of the VARA 2750 Hz wide signal, causing failed handshakes.

5. Comparison: Yaesu FT-DX10 vs. FTX-1 (VARA HF Menu Logic)

While both radios use a similar CAT command set, their menu hierarchies differ. Use this table to quickly find the equivalent setting on either transceiver.

Feature	FT-DX10 Menu Path	FTX-1 Menu Path	Recommended Setting
Operating Mode	MODE > DATA-U	MODE > DATA-U	DATA-U
Audio Input Source	OPERATION SETTING > COMMUNICATION > USB SELECT	MOD SOURCE (Main Menu)	USB
Low Cut Filter	CH GEN > DATA LCUT FREQ	DATA LCUT FREQ	OFF
High Cut Filter	CH GEN > DATA HCUT FREQ	DATA HCUT FREQ	OFF
CAT Baud Rate	COMMUNICATION > CAT RATE	CAT RATE	38400 bps
USB Out Level	COMMUNICATION > USB OUT LEVEL	USB OUT LEVEL	50 (Adjust for RX)
USB In Level	COMMUNICATION > USB IN LEVEL	USB IN LEVEL	50 (Adjust for TX)
AMC / Processor	TX AUDIO > AMC RELEASE TIME	AMC	OFF (for Digital)

Key Differences to Note:

• Menu Depth: The FT-DX10 organizes settings into nested sub-categories (e.g., Operation Setting -> Communication), whereas the FTX-1 uses a flatter menu structure to allow for quicker access in the field.
• Audio Sensitivity: The FT-DX10 internal sound card is generally more sensitive. You may find your VARA Drive Level needs to be slightly lower (around -10) compared to the FTX-1 (around -8) to keep the ALC at zero.
• IF Filter Width: On the FT-DX10, always verify that the physical WIDTH knob is set to at least 3.0kHz (turned to the right). On the FTX-1, this is typically handled automatically when selecting DATA-U.

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6. How to Access & Activate

One of the best features of the FT-DX10 is the PRESET mode. Instead of manually changing menus every time you switch from CW to VARA HF, you can configure a single virtual button to handle all the “under-the-hood” routing.

1. Press the [MODE] button on the front panel (or tap the Mode indicator on the screen).
2. You will see a button labeled PRESET.
   • Blue: Preset is ACTIVE (Digital settings applied).
   • Gray: Preset is INACTIVE (Standard radio settings restored).
3. To switch, simply tap the button. The radio will take ~1 second to swap all 14 internal parameters.

7. Configuring the Preset for VARA HF

The factory default for the Preset is intended for FT8, but we need to tweak it slightly for the wider bandwidth required by VARA.

To edit the Preset:

1. Tap and HOLD the [PRESET] button on the Mode screen to enter its configuration menu.
2. Adjust the following 14 items specifically for VARA/Winlink:

Item	Recommended Setting	Reason
CAT RTS	OFF	Prevents accidental PTT triggers from Windows.
CAT RATE	38400bps	Matches our standard Winlink baud rate.
CAT TIME OUT	10msec	Ensures fast response for data handshakes.
LCUT FREQ	OFF	Critical: Allows VARA’s low-frequency tones through.
HCUT FREQ	OFF	Critical: Allows VARA’s high-frequency tones through.
TX BPF SEL	50-3050Hz	The widest possible “pipe” for VARA Wide mode.
REAR SELECT	USB	Forces audio to come from the USB cable.
RPORT GAIN	50	Mid-point starting value for transmit audio.
RPTT SELECT	RTS	Note: Winlink/CAT overrides this, but RTS is the safe default.
AGC FAST/MID/SLOW	20ms / 500ms / 1500ms	Default values are usually fine.

3. Once adjusted, press the [FUNC] knob to save or tap BACK.

8. The “Gotcha”: IF Filter Width

Even with PRESET active, the FT-DX10 physical WIDTH knob remains active.

• Action: When you activate the Preset for VARA, look at the screen and ensure the WIDTH is shown as 3000Hz.
• If it is narrower (e.g., 500Hz), turn the outer ring of the Multi-dial to the right until it hits 3000Hz. The radio will remember this width specifically for the DATA-U mode within that Preset.

9. Why Use This?

By using the Preset, you can have your radio perfectly tuned for a ragchew on CW (with Narrower TX Filters active), and then switch to Winlink/VARA with exactly one touch. When you tap Preset again to turn it off, all your CW settings (including your CAT baud rate if you use a different one for logging) return to exactly where they were.

10. Safeguarding Your Setup: SD Card Backup

The FT-DX10 allows you to save your entire configuration, including your carefully tuned VARA Presets, to an SD card. This is essential before performing a firmware update or when moving between different operating locations (e.g., Shack vs. Field Day).

SD Card Requirements

• Type: Standard SD or SDHC card (up to 32GB).
• Formatting: The card must be formatted inside the radio to create the correct folder structure.
  • Path: MENU > EXT SETTING > SD CARD > FORMAT

Saving Your Settings

1. Insert the formatted SD card into the slot on the front panel.
2. Navigate to: MENU > EXT SETTING > SD CARD.
3. Select SAVE.
4. You will see several options. Choose INTERNAL DATA.
   • This saves your Menu settings, Mode Presets, and Filter configurations.
5. Select NEW FILE and give it a name (e.g., VARA_SETUP_2026).
6. The radio will write the file to the card. Once “Completed” appears, your settings are safe.

Restoring Your Settings

If you ever need to recover your setup (e.g., after a “Full Reset”):

1. Go to: MENU > EXT SETTING > SD CARD > LOAD.
2. Select INTERNAL DATA.
3. Choose your file (e.g., VARA_SETUP_2026).
4. Select ALL to restore everything, or pick specific categories.
5. The radio will reboot automatically once the load is complete.

Pro Tip: Keep a small 4GB or 8GB SD card permanently in the radio. Not only does it allow for these backups, but it also enables the “Voice Memory” and “Screen Capture” features, which are very handy during emergency communications (EmComm) deployments.