diff --git a/firmware/src/cron.c b/firmware/src/cron.c
index 5e06c5f..21ae449 100644
--- a/firmware/src/cron.c
+++ b/firmware/src/cron.c
@@ -31,10 +31,10 @@
 #include "data.h"
 #include "hw_config.h"
 #include "watchdog.h"
-
+#include "backlog.h"
 
 /* Internal time representation */
-struct tracker_time time = {};
+struct tracker_time time = {0};
 
 /* Pointer to latest datapoint */
 struct tracker_datapoint* dp;
@@ -111,6 +111,11 @@ void do_cron(void)
     pips_telemetry();
 
   }
+
+  /* ---- Record for backlog ---- */
+  if ((time.minute == 0) && (time.second == 25)) {
+    record_backlog(dp);
+  }
 }
 
 /**
diff --git a/firmware/src/main.c b/firmware/src/main.c
index c55a532..70ddfb8 100644
--- a/firmware/src/main.c
+++ b/firmware/src/main.c
@@ -39,8 +39,10 @@
 #include "location.h"
 #include "rf_tests.h"
 #include "data.h"
+#include "backlog.h"
 
 #define CALLSIGN	"UBSEDSx"
+#define APRS_COMMENT	"RTTY/434.6U8N2"
 
 /**
  * Formats a UKHAS telemetry string for the given datapoint
@@ -150,6 +152,8 @@ void contestia_telemetry(struct tracker_datapoint* dp) {
  */
 void aprs_telemetry(struct tracker_datapoint* dp) {
 
+  struct tracker_datapoint* backlog_dp_ptr;
+
   if (!gps_is_locked()) return; /* Don't bother with no GPS */
 
   float lat = (float)dp->latitude / 10000000.0;  /* degrees */
@@ -165,6 +169,19 @@ void aprs_telemetry(struct tracker_datapoint* dp) {
     /* Set location */
     aprs_set_datapoint(dp);
 
+    /* Set comment */
+    if ((dp->time.hour % 2) == 0) {
+      aprs_set_comment(APRS_COMMENT);
+    } else {
+      backlog_dp_ptr = get_backlog();
+
+      if (backlog_dp_ptr) {     /* Backlog comment if we can */
+        aprs_set_backlog_comment(backlog_dp_ptr);
+      } else {
+        aprs_set_comment(APRS_COMMENT);
+      }
+    }
+
     /* Set frequency */
     telemetry_aprs_set_frequency(aprs_location_frequency());