diff --git a/gui/src/js/eventHandler.js b/gui/src/js/eventHandler.js
index 7c4c951a..55029a7d 100644
--- a/gui/src/js/eventHandler.js
+++ b/gui/src/js/eventHandler.js
@@ -43,7 +43,9 @@ export function stateDispatcher(data) {
     stateStore.radio_status = data["radio_status"];
     stateStore.frequency = data["radio_frequency"];
     stateStore.mode = data["radio_mode"];
+    //Reverse entries so most recent is first
     stateStore.activities = Object.entries(data["activities"]).reverse();
+    build_HSL();
     /*
     self.is_arq_state = False
     self.is_arq_session = False
@@ -136,6 +138,33 @@ export function stateDispatcher(data) {
     */
   }
 }
+function build_HSL() {
+  //Use data from activities to build HSL list
+  for (let i=0; i < stateStore.activities.length; i++) {
+    if (stateStore.activities[i][1].direction != "received" || stateStore.activities[i][1].origin == undefined){
+      //Ignore stations without origin and not received type
+      //console.warn("HSL: Ignoring " + stateStore.activities[i][0]);
+      continue;
+    }
+    let found = false;
+    for (let ii=0; ii < stateStore.heard_stations.length;ii++) {
+      if (stateStore.heard_stations[ii].origin == stateStore.activities[i][1].origin) {
+        //Station already in HSL, check if newer than one in HSL
+        found=true;
+        if (stateStore.heard_stations[ii].timestamp < stateStore.activities[i][1].timestamp) {
+          //Update existing entry in HSL
+          stateStore.heard_stations[ii] = stateStore.activities[i][1];
+        }
+      }  
+    }
+    if (found == false) {
+      //Station not in HSL, let us add it
+      stateStore.heard_stations.push(stateStore.activities[i][1]);
+    }
+    }
+    stateStore.heard_stations.sort((a,b) => b.timestamp - a.timestamp); // b - a for reverse sort
+  }
+  
 export function eventDispatcher(data) {
   data = JSON.parse(data);
 
@@ -182,6 +211,10 @@ export function eventDispatcher(data) {
             5000,
           );
           return;
+          case "PING_ACK":
+            //Qrv received
+        displayToast("success", "bi-arrow-left-right", "Received ping-ack from " + "callsignisbroken" + " | " +  data["dxgrid"], 5000);
+            return;
       }
 
     case "modem-event":