+#define TNC_CALLSIGN_OFF 7
+#define TNC_CALLSIGN_LEN 6
+
+static void
+tncSetCallsign(void)
+{
+#ifndef AO_APRS_TEST
+ uint8_t i;
+
+ for (i = 0; i < TNC_CALLSIGN_LEN; i++) {
+ if (!ao_config.callsign[i])
+ break;
+ TNC_AX25_HEADER[TNC_CALLSIGN_OFF + i] = ao_config.callsign[i] << 1;
+ }
+ for (; i < TNC_CALLSIGN_LEN; i++)
+ TNC_AX25_HEADER[TNC_CALLSIGN_OFF + i] = ' ' << 1;
+#endif
+}
+