Connection
Connect the Field head’s PC USB Type-C port with a data cable, not the battery charging port. Install Yaesu’s virtual COM driver. USB carries CAT and TX/RX audio.
Radio settings · AFSK
Hold FUNC → RADIO SETTING → MODE DATA. USB input means the connector, not USB sideband. This guide uses CAT PTT.
| Item | Setting / check |
|---|---|
| Mode / MAIN | MAIN: DATA-L, corresponding to PSRTTY LSB-D. Do not use RTTY-L/U. |
| RADIO SETTING → MODE DATA → MOD SOURCE | USB: explicit TX audio input. AUTO depends on the PTT method. |
| MODE DATA → USB MOD GAIN | Keep working FT8 gain. Default 50 (0–100); adjust with PSRTTY TX volume. |
| MODE DATA → USB OUT LEVEL | Keep FT8 level and check RX. Default 50 (0–100). |
| MODE DATA → RPTT SELECT | OFF: CAT commands control PTT here, not RTS/DTR. |
| CAT-1 RATE / Enhanced COM | OPERATION SETTING → GENERAL → CAT-1 RATE: match PSRTTY. Enhanced COM; default 38400bps. |
| CAT-1 CAT-3 STOP BIT | In GENERAL, check CAT-1 CAT-3 STOP BIT: normally 1bit. |
| MODE DATA → TX BPF SEL | Pass both 2085/2295Hz tones. Default 50-3050Hz. |
| WIDTH / NAR WIDTH | Start wide enough for both tones. Default NAR 300Hz leaves little margin for 170Hz shift. |
| MODE DATA → DATA SHIFT(SSB) | Record and retain the working value. Default 1500Hz; affects carrier position. Check actual transmitted frequency. |
FSK keying transmission · Ver1.18
Example: DTR for FSK and CI-V/CAT for PTT. Adjust settings to your wiring and selected signals.
Serial keying for TX; Audio IN for RX. Neither primary nor secondary Audio OUT is used. Check radio RTTY mode, 170 Hz shift and Mark frequency. Keying polarity is independent of RX inversion.
Connect the radio to the PC with one USB cable to use FSK. See FSK keying output for the radio settings.
Radio settings
| Radio item / connection | Setting / matching |
|---|---|
| Operating mode | PSRTTY RTTY / RTTY-R corresponds to radio RTTY-L / RTTY-U (RTTY-LSB / RTTY-USB), not the AFSK DATA modes. |
| PTT (TX/RX switching) | Set PSRTTY PTT to CAT |
| CAT | Enhanced COM via USB cable (CAT) |
| FSK keying output | Standard COM via USB cable (separate from CAT) |
| RADIO SETTING → MODE RTTY → RPTT SELECT | RTS |
| RADIO SETTING → MODE RTTY → POLARITY TX | NOR |
| RADIO SETTING → MODE RTTY → SHIFT FREQUENCY | 170 Hz |
| RADIO SETTING → MODE RTTY → MARK FREQUENCY | 2125 Hz |
| Audio IN | Use the usual receive audio input |
Assign different signals to FSK and PTT. PC KEYING / RPTT SELECT in the table is the PTT side; the DTR/RTS selected in PSRTTY is the FSK side. For FSK on DTR, use RTS for the PTT side; for FSK on RTS, use DTR. Even with CAT PTT, do not assign the FSK signal to PTT. Do not infer Enhanced/Standard from COM numbers.
Keying polarity mapping
| PSRTTY inversion | DTR OFF | DTR ON |
|---|---|---|
| Not inverted | Mark | Space |
| Inverted | Space | Mark |
The table shows PSRTTY control-signal logic. Match radio POLARITY TX / TX polarity and interface inversion, then verify Mark/Space with the RY test. RX decoding inversion is a separate setting.
If FT8 already works
Keep FT8 devices/gain; verify MAIN DATA-L after connecting. Blue PRESET enables separate settings; disabling restores earlier settings. Recheck MODE DATA and CAT speed after disabling.
PSRTTY settings · AFSK
Select FTX-1, Hamlib and CAT PTT. Specify Enhanced COM (CAT-1), matching baud and this radio’s Audio IN/OUT. Close FT8; test connection. Automatic LSB-D should show DATA-L on the radio.
No modulation
Check DATA-L → MOD SOURCE USB → Audio OUT → USB MOD GAIN/TX volume. For missing RX, check Audio IN/USB OUT LEVEL.
Official sources
- FTX-1 取扱説明書（基本編）
- FTX-1 取扱説明書（詳細編）
- FTX-1 Operation Manual — DATA / PRESET
- FTX-1 Advanced Manual — MODE DATA / CAT
- FTX-1 CAT Operation Reference Manual
Based on official operating, advanced and CAT manuals. Firmware/regional wording may differ.