Beacons

Position reports, objects, trackers, and custom beacons

Beacons are periodic APRS transmissions that announce your station’s position, capabilities, or other information. Graywolf supports multiple beacon types, each with independent scheduling and channel assignment.

The beacon’s callsign defaults to your station callsign — you’ll see (inherited) next to it. You can override per beacon if you want a different SSID for, say, a tracker vs. a digipeater beacon. Click Beacon Now on any beacon card to fire it immediately without waiting for the next scheduled slot.

Beacons page showing a position beacon with GPS, SmartBeacon settings, and turn-based beaconing
A position beacon with live GPS, SmartBeacon rate adaptation, and turn-based corner pegging

Beacon Types

TypeDescription
position Standard position report with symbol and optional comment. The most common beacon type for fixed stations.
object Named APRS object (repeater, event, landmark). Appears on maps with its own callsign-like identifier.
tracker GPS-driven position beacon with SmartBeacon rate adaptation. For mobile stations.
custom Raw APRS info field. Full control over the transmitted packet content.
igate iGate status beacon. Automatically includes iGate statistics in the comment.

Common Settings

FieldDefaultDescription
channel Radio channel to transmit on. Not required when Send to is APRS-IS only.
callsign Source callsign (e.g., N0CALL-5)
destination APGRWO Destination address (identifies software)
path WIDE1-1 Digipeater path
every_seconds 1800 Beacon interval (30 minutes)
delay_seconds 0 Initial delay before first beacon
slot_seconds -1 Fixed slot (seconds past the hour, −1 = unset)
send_path rf Where the beacon is sent — see Where a beacon is sent below

Where a beacon is sent

Every beacon has a Send to setting that controls where it is transmitted:

Send tosend_pathWhat happens
RF only rf Transmitted over the radio on the selected channel. Other igates may relay it to APRS-IS.
RF + APRS-IS both Transmitted over the radio and sent straight to APRS-IS.
APRS-IS only (no radio) is_only Sent only to APRS-IS. No radio transmission and no radio channel required.

APRS-IS-only beaconing (no radio)

You don’t need a radio to put your station on the APRS map. Set a beacon’s Send to to APRS-IS only (no radio) and Graywolf sends it directly to the APRS-IS network over the internet — ideal for a receive-only site, a fixed home station with no transmitter, or anyone who just wants to appear on aprs.fi.

Here’s how the no-radio path works end to end:

APRS-IS-only beacons are injected with a TCPIP* path rather than an RF digipeater path (WIDE1-1, etc.). This is the convention APRS-IS expects for self-originated traffic — servers silently drop self-originated packets that carry an RF path, so Graywolf sets the right path for you. The Path field on the beacon only affects RF transmissions.

Position

Position beacons can use a fixed latitude/longitude or pull live coordinates from a GPS receiver:

FieldDefaultDescription
use_gps false Use live GPS position instead of fixed coordinates
latitude Fixed latitude (decimal degrees, north positive)
longitude Fixed longitude (decimal degrees, east positive)
alt_ft 0 Altitude in feet
ambiguity 0 Position ambiguity (0–3, per APRS101 ch. 6)
compress true Use 13-byte base-91 compressed position format
messaging false Indicate message capability (= vs ! prefix)

Objects

An object beacon transmits a named item (a repeater, a hospital, an event site) on behalf of someone else. The packet carries both the object name and your station callsign as the transmitting source, so APRS clients like aprs.fi display it as NAME (via YOUR-CALL) — making it clear who is injecting the object onto the network.

Use an object beacon (rather than the Override station callsign checkbox on a Position beacon) whenever the item you are beaconing is not your own station. Overriding the callsign makes the packet look as if that name is a real station on the air, which other operators have no way to attribute back to you.

FieldDefaultDescription
object_name 1–9 character object name shown on APRS maps
latitude Fixed latitude (decimal degrees, north positive)
longitude Fixed longitude (decimal degrees, east positive)

Object beacons accept the same Position source choice as Position beacons — either fixed coordinates or the live GPS fix. Fixed is the common case (the object is somewhere other than your station), but GPS-sourced object positions are supported for moving objects that you want to label by name.

Symbols

APRS symbols are selected with a table and symbol code character. On the Edit Beacon dialog, click Choose… next to the Symbol field to pick an icon visually:

Edit Beacon dialog with the Symbol swatch and Choose button
The Edit Beacon dialog — click Choose… next to the symbol swatch

The symbol picker shows both APRS tables (Primary and Alternate). Alternate-table symbols may carry an optional overlay letter or digit (A–Z or 0–9) that is drawn on top of the icon on maps:

Select APRS Symbol modal showing the Alternate table with a Digipeater green star symbol selected and S as the overlay character
Picking the Digipeater (green star) symbol with an S overlay
FieldDefaultDescription
symbol_table / Symbol table: / (primary) or \ (alternate)
symbol Symbol code (single character, e.g., - for house)
overlay Overlay character for alternate table symbols (A–Z or 0–9)

Comments

Beacons can include a static comment or dynamically generate one by running a shell command:

comment Static comment text appended to the position report
comment_cmd Shell command whose stdout becomes the comment (e.g., weather data)

Drop {{version}} anywhere in your comment and graywolf substitutes the running version at send time. The default beacon comment is Graywolf/{{version}}, so your beacon always advertises which release is on the air without you having to remember to update it.

PHG and Repeater Info

Power-Height-Gain-Directivity (PHG) fields describe your station’s RF capabilities per APRS101 chapter 7:

powerTransmitter power in watts
heightAntenna height above average terrain (feet)
gainAntenna gain in dB
dirAntenna directivity (0 = omni)
freqOperating frequency (MHz)
toneCTCSS tone (Hz)
freq_offsetRepeater offset (MHz)

SmartBeacon

SmartBeacon adapts the beacon rate based on speed — faster movement means more frequent beacons, standing still means fewer. Enable it on tracker type beacons:

SmartBeacon Parameters
FieldDefaultDescription
smart_beacon false Enable SmartBeacon rate adaptation
sb_fast_speed 60 Speed (km/h) at which fast rate applies
sb_fast_rate 60 Beacon interval (seconds) at fast speed
sb_slow_speed 5 Speed (km/h) at which slow rate applies
sb_slow_rate 1800 Beacon interval (seconds) when slow/stopped
sb_turn_angle 30 Turn angle threshold (degrees) for corner pegging
sb_turn_slope 255 Sensitivity factor for turn detection
sb_min_turn_time 5 Minimum seconds between turn-triggered beacons

SmartBeacon requires a GPS source. Configure one on the GPS page and set use_gps: true on the beacon.

Immediate Send

Any beacon can be triggered immediately via the API, bypassing the normal schedule. Use POST /api/beacons/{id}/send or the Send Now button in the web UI.