diff --git a/mk2a/mk2a_lms1680.c b/mk2a/mk2a_lms1680.c
index 0d07dac..9df6ee3 100644
--- a/mk2a/mk2a_lms1680.c
+++ b/mk2a/mk2a_lms1680.c
@@ -634,10 +634,16 @@ void print_frame(int len) {
             if (option_jsn) {
                 // Print JSON output required by auto_rx.
                 if (crc_err==0 && (gpx.id & 0xFFFF0000)) { // CRC-OK and FullID
-                    // UTC oder GPS?
-                    printf("{ \"frame\": %d, \"id\": \"%d\", \"time\": \"%02d:%02d:%06.3fZ\", \"lat\": %.5f, \"lon\": %.5f, \"alt\": %.5f, \"vel_h\": %.5f, \"heading\": %.5f, \"vel_v\": %.5f }\n",
-                           gpx.frnr, gpx.id, gpx.std, gpx.min, gpx.sek, gpx.lat, gpx.lon, gpx.alt, gpx.vH, gpx.vD, gpx.vV );
-                    printf("\n");
+                    static ui32_t _id0;
+                    static int frn0;
+                    if (gpx.frnr != frn0 || gpx.id != _id0)
+                    {   // UTC oder GPS?
+                        printf("{ \"frame\": %d, \"id\": \"%d\", \"time\": \"%02d:%02d:%06.3fZ\", \"lat\": %.5f, \"lon\": %.5f, \"alt\": %.5f, \"vel_h\": %.5f, \"heading\": %.5f, \"vel_v\": %.5f }\n",
+                               gpx.frnr, gpx.id, gpx.std, gpx.min, gpx.sek, gpx.lat, gpx.lon, gpx.alt, gpx.vH, gpx.vD, gpx.vV );
+                        //printf("\n");
+                        frn0 = gpx.frnr;
+                        _id0 = gpx.id;
+                    }
                 }
             }