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Digipeater Setup

Digipeater Settings Dialog

The Tracker2 digipeater settings can be configured through either the OTWINCFG Digipeater Settings dialog or via the command line.

Digipeater Basics

An APRS digipeater receives packets and retransmits them, while:

  • Limiting hop count
  • Avoiding duplicate retransmissions

By default, Tracker2 repeats only packets listing its own callsign in the next unused position in the path. This behavior allows for ad-hoc relaying without being a full digipeater.

For standard operation, APRS digipeaters respond to generic aliases (e.g., WIDEn-N) rather than their exact callsigns. For example:

  • A WIDE2-2 path becomes WIDE2-1 after the first digipeater.
  • The next digi uses the final hop and sets it to WIDE2.
cmd:digi on
DIGI ON

The DIGI command enables repeating packets that include the digipeater’s own callsign.

Aliases

Tracker2 supports up to 8 aliases. The HOPLIMIT setting determines how each is matched:

  • HOPLIMIT 0: Matches exact alias only (e.g., SAR, SAR-N)
  • HOPLIMIT > 0: Matches variants like SAR1-1, SAR3-2 etc.

Example behavior: - HOPLIMIT 2 on SAR traps SAR3-3 to SAR3-2, then SAR3-1.

Alias TEMP is enabled by default with HOPLIMIT 2, useful for events or emergencies — not routine use.

Fill-in digis forward only first-hop WIDE1-1 packets and ignore others, helping reduce network QRM. More info:

Recommended fill-in configuration:

ALIAS 1 WIDE1
HOPLIMIT 1 0
USEALIAS 1 ON
DIGI ON
DIGIID 1 ON
PATH -

ALIAS Command Examples

cmd:alias 1 wide1
ALIAS 1:WIDE1

cmd:alias 2 temp
ALIAS 2:TEMP

cmd:alias 3 sar
ALIAS 3:SAR

cmd:alias
ALIAS 1:WIDE1  2:TEMP  3:SAR

cmd:alias 4:foo 5:bar
ALIAS 1:WIDE1  2:TEMP  3:SAR  4:FOO  5:BAR

cmd:alias 2 -
ALIAS 1:WIDE1  3:SAR  4:FOO  5:BAR

Use - to delete an alias.

HOPLIMIT Command

cmd:hoplimit 1 0
HOPLIMIT 1:0

USEALIAS Command

cmd:usealias
USEALIAS 1:OFF 2:OFF 3:ON 4:OFF 5:OFF 6:OFF 7:OFF 8:OFF

cmd:usealias 1 on
USEALIAS 1:ON

ID Insertion

With ID enabled, Tracker2 inserts its own callsign into the path during digipeating.

cmd:digiid 1 on
DIGIID 1:ON

Duplicate Elimination

Tracker2 caches recent packets and skips duplicates for a configured duration (default: 30 seconds):

cmd:dupetime 30
DUPETIME 30

Preemption

Without preemption, only the next unused alias in a path is checked.

With preemption enabled, Tracker2 will match any unused alias in the path. Useful for private networks like SAR operations:

cmd:alias 3
ALIAS 3:SAR

cmd:preempt 3 on
PREEMPT 3:ON

North America (WIDEn-N Paradigm)

  1. RELAY, WIDE, and TRACE are obsolete
  2. Use:
  3. WIDE2-1, WIDE2-2, or SSn-N for fixed stations
  4. WIDE1-1,WIDE2-1 for mobiles
  5. In rural areas without IGates: WIDE1-1,WIDE2-2 is acceptable but may cause QRM

See: http://aprs.org/fix14439.html