Split Operation
Status: Supported · Applies to: FlexRadio
Split operation means listening on one frequency and transmitting on another, the usual way to work a DX station or a pile-up. AetherSDR does it with two slices: your receive slice and a transmit slice beside it on the same panadapter.
Using split
Starting and ending a split
- On the slice you are listening with, click SPLIT on its VFO flag.
- AetherSDR makes that slice the receive slice and creates a transmit slice on the same panadapter, 1 kHz up in CW and 5 kHz up in other modes. Transmit moves to the new slice.
- The receive slice's SPLIT badge turns red. The transmit slice's badge becomes SWAP.
- SWAP exchanges the two frequencies without changing which slice transmits, so you can jump to the DX station's listening frequency and back.
- Click the red SPLIT badge again to end the split. The transmit slice is removed.
The two VFO panels of a split pair stay on opposite sides of the dual-VFO layout so they never cover each other. The SPLIT/SWAP badges follow each slice's actual role, so a diversity child slice is never mistaken for a split partner (see Diversity and ESC).
The badge menu
Right-click either badge (SPLIT or SWAP) for the controls that go with split operation.
Split Up 1 / 5 / 10 kHz
Moves the transmit slice that far above the receive slice. The receive frequency stays where it is. With no split running, the same choice starts one at that offset. Split Up 1 kHz, Split Up 5 kHz and Split Up 10 kHz are also keyboard shortcut actions (see Keyboard Shortcuts).
Monitor TX
Chooses what the Monitor TX (Hold) key does while you hold it:
- Solo TX frequency silences the receive slice so you hear only where you are about to transmit, like XFC, TF-SET or TXW on a conventional transceiver.
- Hear both makes both slices audible for the hold, the way a second receiver would.
Releasing the key puts both mutes back as they were. Monitor TX (Hold) is not bound by default: set a key in Settings → Configure Shortcuts... (and tick Settings → Keyboard Shortcuts, since operating shortcuts are off by default), or put it on a FlexControl, RC-28 or HID controller, where it toggles instead of holding. The menu shows the current binding, or "Not bound — set a key in Keyboard Shortcuts".
Split QSY Option
Split QSY Option ▸ Close split on QSY (off by default) closes a split that AetherSDR created when something outside AetherSDR moves the receive slice (Slice A) by more than a threshold. The threshold is 1 to 200000 Hz, default 2 kHz.
This is for a logging program that sends CAT FA / ZZFA directly to the
radio through its own connection: when the logger QSYs you to a new spot, the
old split goes away instead of transmitting on a stale frequency.
- Echoes of AetherSDR's own tunes (its CAT, TCI, on-screen controls and SWAP) keep the split open.
- Moves at or below the threshold keep the split open and become the new reference point.
- Any other unmatched change to Slice A looks the same as the external CAT case and closes the split.
- Closing removes the transmit slice and returns TX to Slice A. It does not wait for you to finish transmitting.
Forget remembered audio
Clears the remembered audio arrangement (below). The menu also shows a summary of what is remembered, for example "TX unmuted, TX left, TX 40 %, RX right".
Remembered audio
The transmit slice starts muted. If you change that (unmute it, set its level, pan it to one ear and the receive slice to the other), the next split you start comes back the same way, and keeps doing so until you change it.
- Only the transmit slice's mute, level and pan are remembered, plus the receive slice's pan if you moved it.
- The receive slice's own volume and mute are never touched, and its original pan is restored when the split ends.
- Only your own edits teach it: the VFO flag, applets, keyboard and controllers. Changes arriving over CAT, TCI or from the radio do not.
- If you mute the transmit slice yourself before ending a split, the remembered arrangement is cleared, so muting it once returns to the original behaviour.
- Splits started by a logging program or another client over CAT, Hamlib or TCI are left alone.
Split from logging and digital-mode software
- Split is reported per CAT client. Several WSJT-X instances, each on its own CAT port, can all use Split Operation: Fake It at once. See CAT Control and WSJT-X Integration.
- Over TCI, a client's explicit split request still selects the transmit slice, so satellite and cross-band split work. See TCI Server.
Controllers
FlexControl, AetherControl and other controller buttons can run Split Active Slice and Monitor TX Frequency actions. See FlexControl Tuning Knob.
On radios that cannot do split, split controls and controller bindings refuse with a notice instead of silently doing nothing.
Known issues
- After closing a split and switching to another slice on a different band, clicking that band's panadapter can retune Slice A instead of the slice you are on (#2102).
Troubleshooting
Clicking SPLIT shows a notice and nothing happens
The connected radio can't do split, so AetherSDR refuses rather than doing nothing silently.
- Use split on a FlexRadio (or in Demo mode). Other radio families don't offer it.
The split closed on its own after my logger changed frequency
Close split on QSY is on, and something outside AetherSDR moved Slice A by more than the threshold.
- Right-click the SPLIT or SWAP badge and open Split QSY Option.
- Untick Close split on QSY, or raise QSY change threshold to close split in the same submenu.
The Monitor TX key does nothing
Monitor TX (Hold) is not bound by default, and operating shortcuts are off by default.
- Open Settings → Configure Shortcuts... and bind a key to Monitor TX (Hold).
- Turn on Settings → Keyboard Shortcuts.
A new split's transmit slice starts unmuted or panned to one side
AetherSDR remembered how you set up the transmit slice's audio last time.
- Right-click the SPLIT or SWAP badge and choose Forget remembered audio.
- Or mute the transmit slice yourself before ending the split; that also clears the remembered arrangement.