Nexus manual · System

Settings reference

Settings is organized into eight tabs. Only the active tab renders, so typing in one field doesn’t lag the whole panel. Save at the bottom applies your changes; most take effect live (a few say “takes effect on restart”, and a few apply the instant you touch them — those say so too).

Your callsign is required, but Save is never greyed out. Clicking it with an empty callsign takes you to the Station tab with a message saying so, rather than leaving a dead button with no reason and no fix.

The tabs, in the order they appear:

Station · Radio · Modes · Frequencies · Spots & Alerts · Logging & Connectors · Contesting · Appearance

The panel header carries the build stamp (confirm a fresh install actually took) and a Check for updates button.

Station

Your operator identity, license privileges, and default frequency.

Operator & Radio

Callsign — “Your station callsign (required).” Everything keys off this.
Grid — “Maidenhead locator. All 6 characters — 4 measures every distance and bearing from the middle of a ~100-mile square.” Drives satellite passes, propagation anchoring, and distance math.
Operator name — “Used by the CW {NAME} macro and logging.”
State — “Your US state/province — the CW {MYSTATE} macro (ragchew QTH).”
License Class — Technician / General / Amateur Extra (US), or Open for non-US operators. “Sets your transmit privileges + the licensed-segment band dropdown. Open = no limits (outside the US).” This is a software transmit guard in every Nexus TX path, checked against the Part 97 sub-band table — Nexus refuses to key the rig outside your segment.
Band & Frequency — “Pick a band-plan channel, or type a dial frequency in MHz.”

Radio

Everything about the rig itself: the roster, CAT, PTT, satellite Doppler, the rotator, and sound-card routing.

Setup health

A strip above the roster answering “is the station actually working?” — three live indicators, so setup stops running on faith:

Rig — responding / not answering / untested (a live Test CAT result wins over the passive CAT state).
RX audio — the live level in dB, or the audio error.
TX — on / off, and while a tune carrier is keying, the forward power.

Prove TX keys a ~2-second tune carrier to verify the CAT → PTT → RF path. It asks for confirmation first, every time, and reminds you to have an antenna or dummy load connected.

Radios

Run more than one rig. Always shown — with one radio it is just a card and an + Add radio button.

Per-radio cards — rename in place; Active marks your operating radio; Edit loads that radio’s CAT + audio into the form below without changing the radio you’re operating on (no swap, no dropped carrier) and shows an Editing badge; Make active swaps rigs (dropping any carrier first); Remove deletes a non-active radio. The card’s meta line shows model, port/address, audio device, and rigctld port.
Covers bands — band chips per radio for auto band-routing. None = covers all. Appears once you have two radios.
+ Add radio — the discovery affordance. “Run two rigs at once — e.g. an HF radio plus a VHF/UHF radio on a different antenna?”

With two or more radios, three more controls appear:

Routing rules — band coverage sends a whole band to one radio; a rule adds the mode, for when two radios share a band (2 m FT8 to the digital rig, 2 m FM and APRS to the FM rig). Each rule is band chips + a mode class (Weak-signal digital, FM & APRS, SSB phone, CW, RTTY) → a radio. Rules are checked top to bottom and the first match wins; ↑ / ↓ reorder, ✕ removes. Satellite rides the same dropdown but is a context, not a sixth mode: it is matched only by transponder picks, at a tier above the mode rules, so a terrestrial tune never matches it.
Everything else — the default radio for anything no rule and no band coverage matched, or “Stay on the current radio”.
Test a band + mode — pick a band and mode, click Where would this go? and the answer comes from the same resolver the radio loop uses. It does not QSY anything.
Run both radios at the same time — launch Nexus and it asks which radio this window drives; open a second window for the other. Both share one logbook. Leave off if you only ever use one radio at a time — you can still switch between them from the top bar.

Profiles

Saved profiles — Load applies a profile merged onto your current settings; Delete removes it. “Switch a whole rig / antenna / CAT / band setup in one move.” Your callsign, license class, radio roster and sync history never come from a profile, and anything the profile predates keeps its current value.
Save current as — snapshots the current settings under a name.

Rig Control

PTT Method — “How transmit is keyed”: CAT (via rigctld), Serial RTS, Serial DTR, or VOX (no keying). PTT and CAT are independent axes — VOX PTT with full CAT control is a valid setup.
PTT Serial Port — appears on RTS/DTR. The COM port your keying line is on, for an SO2R controller (u2R/MK2R) that routes PTT separately from CAT. Blank = keying shares the CAT port, which is how a single-cable interface like a Digirig Mobile is wired. Per radio.
Zero-config setup ▸ Detect my radio — “One scan for everything: USB radios (fills model, port, sound device) AND FlexRadios on the network (fills the SmartSDR CAT config). Review, then Save.” Each hit gets a Use this button. The list is honest about what it found: a recognised interface cable says so and tells you to pick the rig yourself; a generic USB bridge chip says the port is right but the model isn’t known; a missing Windows driver links the driver. Dual-UART Icoms show two rows and the CI-V one is tagged.
Rig Model — “Hamlib rig model.” A curated ~50-rig list by default; tick Show all models for the full Hamlib catalog, or type a model number directly (“Hamlib may still support it even without a friendly name here”).
Connection — “Serial for a USB/COM rig (most, incl. Xiegu); Network for a FlexRadio via SmartSDR or a remote rigctld over TCP.”
Network Address (Network only) — host:port. For a Flex, the WSJT-X-proven path is the SmartSDR CAT app on this PC: its default TCP port 5002 is directed at slice A, so 127.0.0.1:5002 with the FLEX-6xxx model works out of the box and audio rides DAX. Multi-slice ports are B=60001, C=60002, D=60003 — Nexus drives one slice. (Direct-to-radio :4992 needs Hamlib’s experimental native model and failed on real hardware.) A one-click ⚡ Pair DAX audio button appears when SmartSDR’s DAX devices are detected and neither audio side is already a DAX device — it bootstraps, it does not override a working hand-picked config.
Serial Port (Serial only) — “COM / tty device for rig control — or Auto-test to find it.” Refresh re-scans; Auto-test probes each port read-only (never transmitting) and selects the one that drives your rig. You can type a port that never enumerated. Rig-specific warnings appear inline: Xiegu CAT is on the SERIAL-B port; the Icom CI-V port is the CP210x one marked Enhanced.
Baud (Serial only) — “match your rig’s CAT setting (most modern rigs: 38,400 or 115,200). Native Icom CI-V scope needs 115,200 here and on the rig.”
Antenna rotator — pick your rotator model and its COM port and baud, and “Nexus runs the control daemon for you (same as the rig).” Then use the Rotor pane in Connect, the ↗ on Needed rows, or the compass anywhere. Dummy (testing — no hardware) lets you try it without a rotator; Other Hamlib model #… takes any model number. A separate advanced field takes an external rotctld host:port that overrides all of the above.
ISS SSTV auto-arm — “tunes 145.800 FM and arms the decoder when the ISS is overhead, restores your dial at LOS. Off by default.”
Split operation — None / Rig / Fake It. “Keeps your transmitted audio between 1500–2000 Hz by shifting the TX dial in 500 Hz steps, so audio harmonics fall outside the transmit filter — cleaner signal. Rig = uses VFO B split. Fake It = retunes the VFO around each over (works on any CAT rig). None = stock WSJT-X default.”
Wheel tuning sensitivity — how far the dial moves per mouse-wheel notch. Lower it if a free-spin mouse tunes too far per flick. Applies to the frequency readout and the Phone/CW scope wheel.

Advanced (a collapsed group) holds the rest:

rigctld TCP Port — “Port Nexus launches rigctld on” (default 4532).
Data modes use plain SSB — leave this off unless you know you need it. Nexus normally puts the radio in its DATA submode (DATA-U / USB-D / PKTUSB) for FT8, FT4, RTTY-AFSK and SSTV, because on most rigs that is the only mode where the USB codec reaches the transmitter. On a rig whose codec feeds only the data port, plain SSB takes audio from the mic and the radio transmits no RF at all. Only correct when your transmit audio goes in the microphone path (some RIGblaster models). Per radio. True FSK RTTY is unaffected.
Native Icom CI-V (early access) — appears on a serial IC-7300/7610/9700/ 705/905. Nexus drives CI-V directly instead of launching rigctld, unlocking the rig’s real spectrum scope (“CI-V RF”) and instant dial tracking. Needs 115200 baud set on both the radio and Nexus, plus “CI-V USB Port = Unlink from [REMOTE]” on the rig; below that the rig refuses to stream the scope (CAT still works, the panadapter just stays off).
Flex native panadapter (early access) and Flex native DAX audio (early access) — appear on a network Flex. Stream the real SmartSDR panadapter (VITA-49 FFT) into the cockpit scope, and take RX audio straight off the network instead of the “DAX Audio RX” sound device, which is invisible under Remote Desktop. Both are unverified on hardware, so both are opt-in; if the scope stays blank or decodes stop, turn them back off.
CI-V bus diagnostic log — appears once native CI-V is on. Records every byte to and from the radio to a file in your Downloads, for hardware-only issues like the IC-9700 PTT flicker. Turn on, reproduce, turn off, send the file. It keeps running while you’re on other screens.
Flex radio IP (native panadapter) — the FlexRadio’s own LAN IP (SmartSDR API, port 4992). “This is the radio’s address, not the SmartSDR-CAT port.”
Share my radio (CAT broker) — “Run a rigctld-compatible server so WSJT-X / N1MM / loggers share this radio THROUGH Nexus.” Takes effect right away, no restart, and works even when Nexus is sharing an external rigctld. When on:
- CAT broker port — “Other apps connect here (Hamlib NET rigctl default 4532).”
- Broker PTT — “Let the connected app key transmit when Nexus is idle. Off = other apps control the rig but never key it (Nexus owns TX).” Default off.

Test CAT saves, launches the bundled rigctld (Hamlib ships with Nexus on Windows — no separate install), and reads the rig’s frequency to confirm the link.

Two more controls sit below the Advanced group:

Band-edge tones — “A short audio cue when the dial crosses your license privileges — a rising ‘ding’ back in band, a falling ‘dong’ past an edge.” Applies on every mode, not just digital. On by default.
Max power by mode (safety) — a percentage ceiling on RF output for Phone, CW and Digital; blank = full power. FT8/FT4/RTTY run ~100% duty cycle, so capping Digital (e.g. 30%) protects your finals and any amplifier. The rig is brought down to the cap the moment you enter a capped mode, not only when you touch the power slider.

Satellite Doppler

Corrects both legs of a pass — the downlink you listen on and the uplink you transmit on. Nexus tunes only while auto-track is following a pass and you have picked a transponder in the Satellites section.

Doppler correction — on by default. “Retunes the radio through a pass so you stay on the station you are working.” Clearing it stops both legs.
VFO mapping — which VFO carries your uplink; match it to how your radio is wired. A wrong mapping transmits on your own downlink — into the satellite’s output passband, on top of everyone else working the bird. Picking one applies immediately and confirms it for the radio you are operating; a second radio gets its own confirmation on the pass rail. The control is disabled while you are editing a non-active radio, and says why.
Minimum shift (Hz) — corrections smaller than this aren’t sent. “20 Hz is inaudible on SSB and keeps the CAT link quiet. 0 sends every update.”
Update interval (ms) — shortest gap between corrections. “1000 ms is what a low-orbit pass needs. Shorter fights your own tuning knob and saturates a serial CAT link.”
Pass alert sounds — a rising tone at AOS and a falling one at LOS, alongside the popup. On by default; clearing it silences only the tones, never the popups.

Orbital elements

Keplerian elements (TLEs) for the amateur satellites — pass times, pointing and Doppler all come from them. Refreshed every 6 h from hamradiotools.io: the bird list from the SatNOGS database (CC BY-SA 4.0), the elements from CelesTrak and SatNOGS.

Update now — fetch immediately.
Import from file — a Celestrak TLE, AMSAT keps, or a new launch’s SupGP set; the offline-shack escape hatch. Imports persist across refreshes and the newest epoch per satellite wins.

The status line always shows the bird count, the band coverage, the fetch date and the source. A failed refresh adds a plain-language “Last refresh” line.

Rotator

Pointing manners for the rotator picked under Rig Control. They apply to satellite auto-track.

Park position (° az / el) — “The stow position — wind-safe, or wherever your mast rests. Used only when After a pass is set to Park.”
Ready position (° az / el) — “Where the antenna waits for the next pass.”
After a pass — Stop / Park / Ready. “Stop is the default and moves nothing: the antenna stays pointed where the bird set.” Park and Ready drive the rotator on their own at LOS, so set those positions first.
Tolerance (° az / el) — a new target closer than this isn’t commanded. “Without a deadband the rotator hunts and the relays chatter for the whole pass. 2° is about a G-5500’s own resolution.”
Calibration trim (° az / el) — added to every command. “Use it when the controller reads one heading and the boom points at another.”
Allow flip — takes a high pass by turning azimuth 180° and running elevation past 90°. Off by default: many rotators cannot mechanically go past 90° elevation. Check your controller first.

Audio

With two or more radios, a banner names which radio these devices belong to.

Input Device (RX) — “Sound card carrying receive audio.” Refresh re-scans.
Output Device (TX) — “Sound card feeding the rig (transmit).”
Live input spectrum — what the selected input hears, live. “Band noise should show as a moving floor. Confirms the RIGHT device before you leave Settings.” Flat means no audio on that input.
Tx Power — the audio drive into the rig, the same control as the cockpit Pwr slider (they always match). “Trim down until your rig’s ALC is just zero. This is not the rig’s RF watts — set those on the radio.”
RX Level — a live dB meter like WSJT-X. “Aim for around 30 dB. Anything from ~15–60 dB decodes fine; red means too hot.” An audio error shows here.
RX Gain — “Boost a quiet interface until RX Level reads around 30 dB — the meter responds as you release the slider. Leave at ×1.0 unless the meter reads low (under ~15 dB) — FT8 decodes on a small signal, so you rarely need much.”

Headphone monitor

Enable monitor — plays “the exact audio the decoder hears — for level / RFI diagnosis and listening to the band. Off by default; UNVERIFIED on-air until the attended session.” It guards against the rig’s TX device by name; if your devices go by multiple names, pick your headphones explicitly rather than System default.
Monitor Output Device — “must NOT be the rig’s TX output device.”
Monitor Level — “Headphone listening volume (does not affect TX).”

Modes

One fieldset per mode. Anything that changes the on-air signal or the decode frame lives here, not with the radio.

Digital (FT8/FT4)

Transmit & Sequencing

Transmit period — Tx 1st (even) — “On = transmit in the even/1st T/R slots; off = odd/2nd. The two stations in a QSO must pick opposite periods.” Also on the top bar.
Tx Watchdog (min) — “Auto-halt TX after this many minutes (0 = off).”
Disable TX after sending 73 — “After your final 73 goes out, Enable TX drops — working the next station is a deliberate arm (WSJT-X default). A CQ run is unaffected: it returns to CQ.”
Double-click arms TX — “Double-clicking a station enables TX so the answer goes straight out.” Off = you arm TX yourself each time.
Tune timeout (s) — “Auto-release the tune carrier after this many seconds — never leave a key-down unattended” (default 12).

Auto-CQ & Caller Selection

Stop CQ after N calls — “Blank = WSJT-X behavior: CQ repeats until you stop it (the TX watchdog is the backstop). Set a number to auto-stop an unanswered CQ run.” The Tempo chat CQ run always stops (default 10 unanswered); this number overrides that budget too.
Tempo chat: send cycles per message — “A chat message transmits at most this many cycles, then shows ‘no ack’ (tap the bubble to re-send). Blank = 3 (TempoDeep uses 5). Never affects FT8/FT4.”
Tempo chat: a reply counts as received — when the station you messaged sends a complete message back, stop re-sending and mark yours “confirmed” (works even when the other side isn’t Nexus). A real ACK still upgrades it to “Delivered ✓”.
Auto-CQ: drop a silent caller after N overs — abandon a station that answered then went quiet and return to CQ. “Blank = 3; 0 = never abandon (wait for you, like stock WSJT-X).”
Best caller (auto-CQ pick) — when several stations answer, which to work first: First to answer (default), Strongest signal, Farthest away, or Prefer CQ callers, with an optional minimum SNR.

Logging Behavior

Auto-log QSOs — “Automatically log completed contacts to the ADIF logbook.”
Prompt before logging — a WSJT-X-style confirm-and-edit popup instead of logging silently. “No effect unless Auto-log is on.”
Roger with RRR (not RR73) — “Acknowledge the final report with a bare RRR (partner still owes a 73) instead of the combined RR73. Off = RR73 (modern FT8 practice).”
Clear DX call after logging — wipe the DX Call / DX Grid fields once a contact is logged. Off by default.

Decoder

All Decoder settings drive the native decoder. On a WSJT-X UDP source (Companion mode) decodes arrive already made and none of them apply.

Decode depth — Fast / Normal / Deep. “Deep finds the most signals (WSJT-X default); Fast saves CPU on old hardware.”
Decoder passband (Hz) — F low / F high, default 200–2900 Hz. “Raise F high toward 4000 Hz to decode stations calling above ~2.9 kHz (common on crowded FT8 bands); lower the range to focus on a narrow filter or dodge strong close-in QRM.”
A-priori (AP) decoding — FT8 — retry marginal signals against hypotheses built from your call, the DX call and the QSO state, including the cross-cycle replay of last cycle’s QSOs. On by default. FT8 only: FT4’s AP is part of its Normal/Deep depth and has no separate switch.
AP: CQ hypothesis only — limit AP to the “CQ” guess, no MyCall/DxCall hypotheses (FT8 and FT4). “WSJT-X switches to this by itself after 5 minutes without transmitting, as a guard against stale-context false decodes; here it is your explicit choice.”
Single decode — decode only within ±25 Hz of your green RX marker instead of the whole passband. Isolates one weak station and saves CPU. FT8 and FT4 only: 50 Hz is narrower than a single JT65, Q65 or MSK144 signal, so those modes keep the full passband.
DXpedition mode — Off or Hound. “Hound = DXpedition pile-up discipline (calls above 1000 Hz; your report auto-moves to the Fox’s frequency).”

Station Housekeeping

Journey — track a weekly streak — off by default. “A gentle ‘weeks on the air’ counter on the Journey board — never a daily streak, never a penalty for a break.”
Beacon — announce presence (CQ) — “Off = passive (hunt & pounce): Nexus listens and only transmits when you act. On = periodically calls CQ to announce you’re on frequency.”
IR-HARQ — combine retransmissions — on by default. “A weak frame that fails is recovered by joint-combining its retransmissions (RV0+RV1+RV2), and unacknowledged QSO overs escalate redundancy. Off = RV0-only.” (TempoFast/ TempoDeep — see the Tempo chat layer.)
Clock check (NTP) — check the PC clock against an NTP server and show the offset in the top bar. “TempoFast/TempoDeep are slot-timed to UTC — keep it within ~0.5 s.” Turn off for fully-offline operation (no network calls).
Station power (W) — “Your transmit power in watts — unlocks the Journey miles-per-watt & QRP feats.” It also feeds the P.533 link budget. Leave blank if unknown.

JT65 — classic EME

Submode (tone spacing) — A (HF standard, narrowest), B (2× spacing), or C (4× spacing, most Doppler-tolerant). “JT65 always uses a 60 s T/R period, so spacing is the only choice. A is what you want on HF; EME operators move up to B or C as Doppler spread on the higher bands smears the tones. Both stations must use the same submode.”

JT65 transmits and receives. Its messages are the older 22-character format, not the 37-character one FT8 and friends use — nothing downstream cares, decodes are just shorter.

MSK144 — meteor scatter

T/R period — 5 s (fast turnaround, big showers), 10 s, 15 s (the 6 m standard), or 30 s (sparse pings, more to stack). Both stations must match.

MSK144 transmits for nearly the whole period, sending the same 72 ms frame hundreds of times — that is how meteor scatter works, and a contact can take many minutes of apparent silence. The audio frequency is fixed at a 1500 Hz centre and the signal is 1 kHz wide, so there is nowhere to tune it. Shorthand (MSK40) messages are off, matching WSJT-X’s default.

Beacons — WSPR & FST4W

A separate surface from the QSO modes: there is no exchange, only a schedule. Off by default — beaconing keys the radio unattended, so it is always an explicit choice.

Transmit % — “Fraction of intervals to transmit on. 0 = listen only. A beacon that transmits every interval hears nothing, so a minority is the convention — 20–30% is typical.” Below 40% Nexus also avoids back-to-back transmissions while still hitting the rate you asked for.
Transmit power (dBm) — required, and it has to be real. “WSPR reports are published to a public propagation database that other operators draw conclusions from, so a wrong figure corrupts their data as well as yours. The beacon stays silent until this is set. 23 = 200 mW, 30 = 1 W, 37 = 5 W, 43 = 20 W.”
FST4W Round Robin slot — “0 = use the transmit-% schedule. Otherwise your slot in a coordinated rotation: stations agreeing on the same slot count and each taking a different slot never transmit at the same time, because the assignment is fixed by UTC.”
Round Robin slots — how many stations are in the rotation. Ignored when the slot is 0.

Beacons transmit your callsign, grid and power, so Call CQ and S&P are inactive on these tiers. Transmit still has to be armed as usual: the schedule never keys a radio whose transmit you have not enabled.

FST4 (QSO) / FST4W (beacon)

T/R period — 15 / 30 / 60 / 120 / 300 / 900 / 1800 s, shared by both tiers. “Longer periods hear weaker signals at fewer exchanges per hour. FST4W beacons run at 120/300/900/1800 s; FST4 QSO work is usually 15–60 s.”

FST4 is the QSO mode, FST4W the WSPR-like beacon mode — pick which on the tier selector. Both transmit; the difference is that only FST4 has an exchange to sequence, so FST4W keys on the schedule set under Beacons above. FST4W hashed callsigns show as <...>: the lookup table upstream fills from a file this build does not carry. (The fieldset’s in-app note still says Nexus transmits neither; that text is stale — both report tx: true.)

Q65 — EME / VHF+ scatter

T/R period — 15 s (troposcatter), 30 s (6 m meteor / ionoscatter), 60 s (EME, most common), 120 s (deep EME), 300 s (deepest, microwave EME). Changing it changes the decode frame length, so it takes effect on the next slot.
Submode (tone spacing) — A through E. “Wider spacing survives more Doppler spread and frequency drift but costs sensitivity. Move up the letters as the path degrades — EME on the higher bands usually needs B or C.”

Q65 transmits and receives, and both stations must match: a correspondent on a different period or submode will not decode you.

Quick-reply macros

Comma-separated chip lists for the quick text you fire from each surface:

Chat — chips for Chat.
QSO — chips for sequenced QSOs.
Band / CQ — open broadcasts: the Call CQ launchpad and band feed.

Phone (SSB / FM)

Mode

Phone mode — SSB (USB/LSB by band) or FM. “FM drives the rig to FM + the shift/tone below.”
Repeater shift (FM only) — simplex / plus / minus. “Offset is the band standard (2 m 600 k, 70 cm 5 M…).”
CTCSS (PL) tone (FM only) — the repeater access tone, off or a standard EIA tone.

Microphone

Voice mic (recording) — “Mic used when RECORDING a voice-keyer message. Default records from the audio input device — but on a digital setup that’s the rig’s RX audio, so you’d record the band, not your voice. Pick your actual mic here.” If it can’t open, recording falls back to the input device — never silent.

Mic gain and voice-keyer message recording are in the Phone cockpit, not here.

CW

Keyer

Keyer backend — four ways to send, also switchable live from the CW cockpit. CAT uses the rig’s internal keyer (Hamlib send_morse), but older rigs (e.g. IC-756PRO III) don’t support it. Serial keyline toggles DTR/RTS into the rig’s KEY jack — the clean N1MM/fldigi method, needs only a keying cable. WinKeyer drives a K1EL. Soundcard keys an audio tone through SSB — a workaround; set drive so ALC reads zero.
Sidetone pitch (Hz) — 300–1200 Hz. Sets the soundcard keyer tone and the CW scope zero-beat marker.
WinKeyer port — “For the WinKeyer CW keyer (select it above). 1200 baud.”
Keyline serial port (serial keyline only) — the USB-to-serial into your keying interface (Buxcomm, US Navigator, a homebrew DTR cable) that plugs into the rig’s KEY jack. “Must be a SEPARATE port from CAT. Set the rig to CW and its key-jack to straight-key / bug.”
Keying line (serial keyline only) — DTR (the CW convention) or RTS. “DTR is standard (RTS = PTT); flip to RTS if your interface is wired the other way.”
CW ID after 73 — keys your callsign in CW once the final 73 has fully left the air (stock WSJT-X option, default off). It uses the normal CW keying path — PTT + tone — after the FT8 over, never on top of it.

Macros (F-key profiles)

CW cockpit F-keys — named macro profiles (New / Rename / Delete, at least one always kept), switchable here or in one click from the CW cockpit bar. The grid edits the active profile: a label and a template per key. Customize starts from the built-in F1–F8 set; Reset to defaults returns to it. Tokens: {MYCALL} {NAME} {MYGRID} {MYSTATE} {RST}, ! = the worked call, and {HISNAME} {HISSTATE} = the worked station’s QRZ name and state. Each key keeps its role (F1 CQ, F2 answer, F3 report, F4 sign off, F5 my call, F6 his call, F7 ask repeat, F8 query), so the Guided copilot’s next-step highlight still rolls F1→F2→F3→F4 through customized text.

RTTY

Keying

Keying backend — AFSK plays the two-tone waveform through the same TX audio path as FT8 (soundcard-clocked, jitter-free; set drive so ALC reads just zero). True FSK bit-bangs the rig’s FSK input over a serial control line with the rig in RTTY mode, unlocking its narrow RTTY filters. “Software FSK timing is casual/Field-Day grade; AFSK is the timing-cleanest path.”
FSK serial port (True FSK only) — the port whose control line feeds the rig’s FSK input. Empty = the CAT serial port.
FSK data line (True FSK only) — DTR (the common wiring, leaving RTS free for PTT) or RTS. “PTT must ride its OWN path — CAT PTT or the separate PTT line, never this one; Nexus refuses a send if they collide.”

Signal

Baud rate — 45.45 (the HF standard) or 75. Drives the TX bit clock and the RX demodulator — true 45.45, never rounded to 45.
Shift (Hz) — 170 (the HF standard), 425 or 850. The TX tone pair and the RX demodulator both.
Reverse (swap mark/space) — “The convention is LSB with mark on the lower audio tone. Turn this on when deliberately running the opposite sideband (e.g. AFSK in USB/DATA-U) so the on-air sense stays correct.” Applies to TX and the RX decoder.

APRS

APRS-IS (internet feed)

APRS-IS feed — “Plot stations the internet reports alongside the ones your own antenna hears — each one tagged so you can always tell which is which. Runs whether or not the APRS decoder is armed: it uses no radio and never transmits.” If internet stations appear while your receiver stays silent, the fault is in the RF chain.
Server — “Your regional Tier 2 rotate is best — noam / soam / euro / asia / aunz .aprs2.net. rotate.aprs2.net works anywhere.”
Port — “14580 is the filtered port clients and iGates should use. The full-feed ports would send you the entire planet.”
Radius (km) — how far around your grid to subscribe. “APRS is a local mode; 150 km is a generous 2 m-plus-digipeater horizon. 0 = no distance limit (busy).”
Watched calls — comma separated. “These come through from anywhere on earth, however far outside your radius they are — the club tracker on a road trip, a friend chasing a summit.”
Weather stations — include weather reports in the feed.
Objects & items — repeaters, NWS alerts and event markers other stations have placed on the map.
Messages — show APRS text messages from the feed. Display only — replying to an internet message is not wired up.
Keep stations for (min) — how long a station stays on the map after its last packet; they start to fade at a third of this. An hour by default, because fixed stations often beacon only every ten to thirty minutes and a shorter window makes the slow ones blink off between their own beacons. 0 keeps every station forever (the 2000-station ceiling still applies).
Receive-only iGate — contribute packets your own antenna hears to APRS-IS, so stations in your area reach the global map through you. It publishes under your callsign, so it is a separate choice from watching the feed, and it needs the APRS decoder running to have anything to send. Nexus never sends the other way: gating the internet back onto the air means transmitting unattended.

Frequencies

Working Frequencies

The dial frequency used when a band/mode is selected. These are overrides of the stock WSJT-X working-frequency table — “leave the list empty to use stock everywhere. An override replaces the stock row for its band + mode.”

Standard table (read-only) — the stock WSJT-X dial frequencies. A row with an active override shows your value, highlighted.
Your overrides — rows of band + mode + dial MHz. Add override adds a row, Reset to standard clears them all, ✕ removes one. “MHz is the dial (suppressed-carrier) frequency.” A duplicate band+mode is flagged inline and the last row wins. Save to apply — band switches then use your value.

Spots & Alerts

What Nexus tells you about, and how loudly. Kept quiet by default so the app doesn’t cry wolf.

Pounce — new-one alert

Interrupts you the instant a needed station appears on the cluster or RBN, rather than waiting for the spot board to refresh. A loud tone plays whether or not Nexus is the window you are looking at, and a banner offers one-click Work. Each station alerts once per band and mode.

Alert me for — Off (default) / New DXCC entity only / New entity or CQ zone / New entity, zone, or US state.

How rare “rare” is depends on your own totals: if you are chasing your first hundred entities then almost every DX spot is a new one and this would never stop talking. Start with New DXCC entity only once your log is far enough along that a new one is genuinely an event.

Accessibility & eyes-free

Speech and sound cues for operating by ear. The keyboard and screen-reader labels throughout Nexus are always on — these settings only control what comes out of the speakers.

Announce decodes (screen reader) — Off / Needed only (calling you / new / watched) / All (adds a per-cycle CQ summary). Silent without a reader running.
TX / RX earcon — “A rising tone when you key up, falling when you unkey — know your TX state by ear.”
Decode-batch tick — “A soft tick each cycle new signals are decoded — the band’s rhythm, eyes-free.”

Alerts

My call — “Beep + flash when someone directs a call at you.”
CQ calls — “Alert on any decoded CQ. Off by default — CQs are constant.”
New DXCC — Off / HF only / VHF+ (6 m and up) / All bands. “Loud alert on a new DXCC entity — a ‘new one’. Does NOT alert on every decode.”
New grid — same band scopes. “Quiet toast on a grid you haven’t worked. Default VHF+ only — grid awards (VUCC/FFMA) start at 6 m; on HF nearly every decode is an unworked grid.”
Rare grid 💎 — same band scopes. “The loud 💎 alert for rare/water-only grids (rovers, maritime, DXpeditions) — separate from plain grids so silencing HF chatter keeps the gems.”
Watch list — the calls you want flagged wherever they turn up.

Logging & Connectors

Where QSOs go and what feeds come in. Credentials live in the OS keychain, never on disk; a saved password or key isn’t shown again after you click Set, and Forget removes it.

Connections

A status grid of every connector — a dot for “credential stored”, plus the stored identity — and a Test button on QRZ Logbook that round-trips the API without logging anything. Below it, a session Connection log: “every save, sync, push, and failure lands here.”

Integrations & Feeds

Local APIs & Loggers

WSJT-X UDP API + UDP Address — “for JTAlert / GridTracker / loggers” (default 127.0.0.1:2237).
Ham Radio Deluxe logging + HRD UDP Address — push each QSO to HRD Logbook over its QSO-Forwarding UDP port (default 127.0.0.1:2333). HRD must be running, and don’t also run JTAlert/QSO Relay into HRD or you’ll double-log.
Companion UDP address — “Where Nexus listens for WSJT-X/JTDX in Companion source mode.”
Write ALL.TXT decode log — WSJT-X-format decode log for GridTracker / loggers to tail. “Written only while this is on, and it first appears after the next decode.” The saved path is shown, with Reveal in folder.
Save a WAV per logged QSO — “Auto-records the last ~60 s of RX audio to the recordings folder on log.”
Save received audio (.wav per period) — None / periods with decodes / all periods. WAVs land in recordings/periods (12 kHz mono, ~360 KB each). “‘All’ writes ~2 GB/day of continuous monitoring — use for decoder debugging, not always-on.”

Spot Sources

PSK Reporter — “upload spots to the global map.”
DX Cluster / RBN spots — “Surface ‘new ones’ from the Reverse Beacon Network on the Needed board + Connect.” Takes effect on restart.
Phone/SSB cluster nodes — human DX-cluster nodes for SSB/phone spots, since RBN only carries CW and digital. “We connect to ALL listed nodes and union their human SSB/phone spots — more nodes = wider phone coverage.” Add from the + Add a known node… presets (VE7CC-1 recommended; WA9PIE-2 on port 8000 if 23 is blocked; W1NR phone-rich; W3LPL the skimmer-heavy firehose) or + Custom. An added node connects on the next Save; removing one takes effect on restart.

Propagation

Near-region opening watch — “Watch VHF/10 m activity near your QTH (not just your own contacts) so openings flag ‘open around you’ before you’ve worked anyone.” Takes effect on restart.
Prediction engine — Modelled (fast heuristic) or ITU-R P.533 (full physics). “P.533 is the real circuit-reliability method (validated against the ITU reference; ~0.1 s per prediction, uses your station power). Live spots always win over any model.” See Connect.
Antenna gain (dBi) — TX / RX (under Antenna gain (advanced)) — “Used by the P.533 link budget only. 0 = a simple wire/vertical (isotropic); a 3-element yagi ≈ 6–8. Honest v1: a plain dB shift — no pattern or takeoff-angle modelling, and the fast heuristic ignores it.”

DXKeeper (DXLab Suite)

Pushes each logged QSO into DXKeeper over its TCP Network Service. Enable it in DXKeeper under Configuration ▸ Defaults ▸ Network Service first.

DXKeeper host — “Usually 127.0.0.1 — same PC. Leave blank to disable.”
DXLab Base Port — the Base Port from DXKeeper’s Network Service panel (default 52000). DXKeeper itself listens on base + 1 and Nexus adds the 1 for you, so the number you read off DXKeeper is the number that works.
Let DXKeeper do the uploads — “Off by default: Nexus already uploads to LoTW / eQSL / ClubLog / QRZ, so turning this on would upload every QSO twice.” DXKeeper ignores it for Club Log and QRZ if Auto upload is ticked on its own QSL Configuration tab — untick it there.

N3FJP Integration (club master log)

“Each FD contact lands in the club’s N3FJP Field Day Contest Log the moment you log it — so the whole club’s score updates in real time.” Run N3FJP on the master computer and point Nexus at its IP and port.

N3FJP host — IP or hostname of the master log computer. Blank = off.
N3FJP port — N3FJP’s API TCP port (default 1100).
Use ENTER for Field Day scoring — on by default. Logs each FD contact with N3FJP’s ENTER sequence, “which scores the contest — the correct path.” Off falls back to a plain ADDDIRECT insert, which may not score.
Report my band to N3FJP — “Tell N3FJP which band you’re on (no CAT needed), so the club’s Network Status Display band board shows this position.” Off by default.
Forward every QSO — also push every logged QSO, not just Field Day, to N3FJP ACLog. “N3FJP dedupes, so it’s safe to run alongside the Field-Day push.”
Connection test — Test N3FJP saves, then tests the TCP link. “Run this at the club site before the event starts.”

N1MM+ Integration

N1MM contact broadcast address — host:port, UDP. “Name the port — consumers stack on one host, and 12060 is often already taken by another logger.” Blank = off. An address alone sends nothing outside a Field Day event.
Broadcast every QSO — send the contact packet for every logged QSO, not just Field Day: point OpenHamClock or GridTracker at the address and each contact plots as you log it. “One packet per QSO: this never doubles up with the Field Day broadcast.” Off by default; turning it on with a blank address fills in 127.0.0.1:12060 visibly, rather than as a hidden default.

LoTW users list

Fetch now — downloads ARRL’s weekly activity list; the status line shows the call count and date. This powers the teal L marks on decode and roster rows.
Count as a LoTW user if uploaded within (days) — the recency window (default 365).

“ARRL’s activity list updates weekly — refetching more often just returns ‘unchanged’. Manual fetch by design (WSJT-X convention).”

Callsign → state database

Update now — “A callsign→state index (from the FCC license file) so a New State lights up on cluster / CW / SSB spots that carry no grid.” Downloads on first launch, then auto-refreshes weekly from hamradiotools.io; a live decode grid refines it for rovers.

Confirmations

LoTW

LoTW username — “Often your callsign, but not always — use your LoTW account login.”
LoTW password — your LoTW website password, not your TQSL certificate password.
LoTW sync — Sync LoTW now “pulls new confirmations into your log and marks which of your uploads LoTW now holds on file (so they read ‘waiting on the other op,’ not ‘never uploaded’).” The first sync pulls your whole history and can be slow; later syncs are incremental.
LoTW Station Location — for uploading. Signing is done by your installed TQSL against this named Station Location — set it up in TQSL first; the name must match exactly. No certificate or password is stored by Nexus.
Sign from ADIF location (travelers) — turn on if you set TQSL to “use the location in the ADIF file” rather than creating named Station Locations. Nexus then stamps your call and grid into the upload and omits -l. The whole batch is signed from your current grid, so if you operate from more than one location, upload before you move.
TQSL path (optional) — “Only if TQSL is installed somewhere non-standard; otherwise leave blank to auto-detect.”

eQSL

eQSL username / eQSL password — your eQSL.cc login, often your callsign.
eQSL confirmations — Sync eQSL now downloads confirmations into your log. “These count as confirmations but not for DXCC/WAS (ARRL doesn’t accept eQSL) — a separate tier.”
Auto-upload QSOs to eQSL — upload each logged QSO as you log it.

QRZ

QRZ username / QRZ password — “this is what powers callbook lookups” (name, QTH, grid). Separate from the Logbook API key below, which only uploads QSOs. “Grid & state need a QRZ XML subscription; free accounts return only name/address/country.”
QRZ Logbook API key — a separate key from your QRZ logbook’s settings page, used to upload logged QSOs.
Auto-upload QSOs to QRZ — push each logged QSO to your QRZ logbook.
Pull confirmations automatically — “As people confirm on QRZ, the confirmations flow in on their own — no need to press Sync. After the first run only what CHANGED is fetched.” The last pull time is shown. QRZ confirmations never count toward DXCC or WAS, which need LoTW or a card.
Two-way sync — Sync from QRZ now pulls your QRZ logbook down, adding QSOs you logged elsewhere (e.g. a phone app in the field) and marking QRZ-confirmed contacts. Safe to run repeatedly (deduped).

HamQTH

HamQTH username / HamQTH password — “A free callbook used as a fallback when QRZ isn’t configured or has no match — a HamQTH account returns name, grid & US state at no charge.”

ClubLog

ClubLog email — your ClubLog login email, not a callsign.
ClubLog callsign — “The ClubLog logbook to upload into (empty = your callsign).”
ClubLog app-password — “Use a ClubLog Application Password (Settings → App Passwords), not your main password.”
ClubLog API key (application-level) — “This is the application credential, not yours — official installer builds bundle one, and you only need email + app-password above. Building from source? Request a free key at clublog.org/requestapikey.php and paste it here (open-source can’t ship one — ClubLog auto-revokes published keys).”
Auto-upload QSOs to ClubLog — push each logged QSO in real time.

HRDLog

HRDLog.net upload code — from your HRDLog.net account (Options → your code). Uploads log under your station callsign. “This is the online HRDLog.net service — separate from the HRD Logbook UDP push under Integrations & Feeds.”
Auto-upload QSOs to HRDLog.net — “HRDLog.net is a live-logging and awards site — it is not an ARRL confirmation source, so an upload here never earns DXCC/WAS credit.”

RepeaterBook

RepeaterBook API token — optional. “Without a token the Program section uses the open hearham.com directory. Add a personal token (from your RepeaterBook account’s API Apps page) to pull from RepeaterBook.com under your own account instead.” Shared RepeaterBook access for every Nexus user is pending RepeaterBook’s approval; if RepeaterBook is unreachable, Program falls back to hearham.com.

Cloudlog / Wavelog

Auto-forward each logged QSO to your self-hosted Cloudlog or Wavelog logbook over HTTP.

Base URL — your site root. “Leave blank to disable.”
Station profile id — “The station-location profile to log against (Cloudlog ▸ Station Locations).”
API key — “Cloudlog ▸ Account ▸ API Keys — a key with read/write.” A per-instance token for your own server.
Auto-forward QSOs — push every logged QSO to the instance above as it’s logged.

Contesting

Always visible — capability, not configuration, gates the tabs.

Contest Category

Unassisted entry — “Turns off the AI CW decoder, DX cluster / RBN spots and the PSK Reporter needs feed together, and records the change with a timestamp. Takes effect at once” — its own command, not Save, because an operator flips it as an event starts. “Your own settings for each of those are left alone and come back when you switch this off.”
Assistance record — the timestamped journal: a row per flip and a row each time Nexus starts, with which sources were active. Kept in assistance_journal.json beside your settings, so it survives restarts. Newest first.

Field Day Setup

Field Day mode — the master switch. “Turn on for Field Day weekend — reveals the Field Day workspace and the Class/Section exchange across all modes. Off the rest of the year.” It stays on across restarts until you turn it off. The same switch also appears in Appearance ▸ Features under Contesting — Field Day visibility is owned by this persisted setting, not by a feature flag, so the Features group hosts the master rather than a separate toggle.
Event — ARRL Field Day or Winter Field Day. “Affects scoring labels and export headers.”
FD Class / WFD Category (the label follows the Event) — “Number of transmitters + class letter: A=club/group portable, B=1–2 person portable, C=mobile, D=home (mains power), E=home (emergency power), F=EOC. E.g. 3A.” For WFD: “Transmitters + location: H=Home, I=Indoor, M=Mobile, O=Outdoor.”
ARRL Section — “Your ARRL / RAC section (e.g. WI, ENY, ONN). Start typing the code or a state name and pick from the list.” Every entry is validated against the full ARRL/RAC list and an unknown one is flagged inline, so it never silently reaches the Cabrillo log.
Power multiplier — ×5 (QRP/battery, ≤5 W on natural power), ×2 (≤100 W), ×1 (>100 W). “Multiplies your QSO points. Choose before the event.”

Class and Section start empty on purpose and the station won’t enter Field Day until both are set — a banner says so while the mode is on and they’re blank. See Contesting & POTA/SOTA.

Appearance

UI-only preferences (applied live, not via Save) and the section toggles.

Workspace

UI scale — Auto (fit) scales the whole interface to the window so nothing is cut off, with Max scale cap chips so auto never overshoots on a big monitor. A cap this window can’t reach is disabled and its tooltip says why (“a larger window or monitor unlocks it”). Manual picks a fixed percentage instead. The waterfall stays sharp either way.
Density — Comfortable or Compact. “How tightly rows and controls pack. Compact fits more on screen.”
Pane sizes — Reset pane sizes restores the default pane widths. Pane layout itself is set in the cockpits: drag the dividers between panes to resize (double-click a divider to reset), and use the ⊞ menu to show or hide panes.

(The theme picker — dark / light / amber night-vision — lives in the app chrome, not this tab.)

Features

Turn sections on and off, and pick a goal profile.

Profile — a goal (getting started, DX/awards, contesting, POTA/SOTA, 6m/VHF) sets sensible defaults. “Pick a goal to set sensible defaults — every feature stays toggleable below.” Hand-toggling produces a Custom set, and switching away from Custom asks first because it discards your hand-tuned set. A Re-run setup… link reopens the first-run wizard.
Core — always on — the spine (Operate, Logbook, Settings, Now Bar, Chat, Connect, Needed) shows an “always on” badge instead of a toggle: a locked switch beside real ones just reads as broken.
Optional features, grouped by category in this order: Operate, DX & Awards, Propagation, Contesting, POTA/SOTA, Logging, System. Each row is a toggle with a one-line “why you’d want it”. Enabling a feature pulls in anything it depends on, and the hint names what else it will turn on.
The Contesting group hosts the Field Day mode master switch (the same setting as Contesting ▸ Field Day Setup). Turning it on with no Class or Section set jumps you to the Contesting tab to fill them in.

This page is synced from docs/guide/settings-reference.md in the Nexus repo. Corrections belong there.