diff --git a/pyBMNotify.py b/pyBMNotify.py
index 7ac997e..4af2da8 100644
--- a/pyBMNotify.py
+++ b/pyBMNotify.py
@@ -1,10 +1,18 @@
 from socketIO_client import SocketIO
 import json
 import datetime as dt
+import time
 
-tg = [91, 98002]
-min_duration = 2
 id = ""
+last_activity = {}
+
+
+# adapt the following variables to your needs
+talkgroups = [91, 98002] # Talkgroups to monitor
+#dmr_ids = [2637550]
+callsigns = ["DL6MHC", "OE1MEW"]
+min_duration = 2 # Min. duration of QSO to qualify for a push notification
+min_silence = 300 # Min. time in seconds after the last QSO before a new push notification will be send.
  
 def on_connect():
     print('connect')
@@ -15,22 +23,42 @@ def on_disconnect():
 def on_reconnect():
     print('reconnect')
 
-def on_mqtt(*args):
+def construct_message(c):
+    tg = c["DestinationID"]
     out = ""
+    duration = c["Stop"] - c["Start"]
+    #print(c["DestinationName"])
+    # convert unix time stamp to human readable format
+    time = dt.datetime.utcfromtimestamp(c["Start"]).strftime("%Y/%m/%d %H:%M")
+    # construct text message from various QSO properties
+    out += c["SourceCall"] + ' (' + c["SourceName"] + ') was active on '
+    out += str(tg) + ' (' + c["DestinationName"] + ') at '
+    out += time + ' (' + str(duration) + ' seconds)'
+    #print(json.dumps(call,separators=(',',':'),sort_keys=True,indent=4))
+    # remember ID to prevent doublets
+    #id = call["SessionID"]
+    #last_activity[tg] = call["Start"]
+    # finally print out the text message
+    print(out)
+
+def on_mqtt(*args):
     global id
+    # get json data of QSO
     call = json.loads(args[0]['payload'])
     #print(json.dumps(call,separators=(',',':'),sort_keys=True,indent=4))
-    #if call["DestinationID"] in tg and id != call["SessionID"]:
-    if call["DestinationID"] in tg and call["Stop"] > 0 and id != call["SessionID"]:
+    # check if talkgroup is one of those to be monitored, if QSO has already been
+    # ended and the same QSO has already been handled
+    tg = call["DestinationID"]
+    if call["SourceCall"] in callsigns:
+        construct_message(call)
+    elif tg in talkgroups and call["Stop"] > 0 and id != call["SessionID"] and (tg not in last_activity or (last_activity[tg] + min_silence) < call["Start"]):
+        # calculate duration of QSO
         duration = call["Stop"] - call["Start"]
-        if duration > min_duration:
-            time = dt.datetime.utcfromtimestamp(call["Start"]).strftime("%Y/%m/%d %H:%M")
-            out += call["SourceCall"] + ' (' + call["SourceName"] + ') was active on '
-            out += str(call["DestinationID"]) + ' (' + call["DestinationName"] + ') at '
-            out += time + ' (' + str(duration) + ' seconds)'
-            #print(json.dumps(call,separators=(',',':'),sort_keys=True,indent=4))
+        # only proceed if QSO has the configured min. duration
+        if duration >= min_duration:
+            construct_message(call)
             id = call["SessionID"]
-            print(out)
+            last_activity[tg] = call["Start"]
 
 socket = SocketIO('https://api.brandmeister.network/lh')
 socket.on('connect', on_connect)