diff --git a/apps/fft-multi-decoder_auto_freqs_slider-update.grc b/apps/fft-multi-decoder_auto_freqs_slider-update.grc
index 675a38c..f10d783 100644
--- a/apps/fft-multi-decoder_auto_freqs_slider-update.grc
+++ b/apps/fft-multi-decoder_auto_freqs_slider-update.grc
@@ -3080,7 +3080,7 @@ class blk(gr.sync_block):  # other base classes are basic_block, decim_block, in
     </param>
     <param>
       <key>debug</key>
-      <value>False</value>
+      <value>True</value>
     </param>
     <param>
       <key>_enabled</key>
diff --git a/python/max_freq.py b/python/max_freq.py
index 32ff34a..89bedbe 100644
--- a/python/max_freq.py
+++ b/python/max_freq.py
@@ -21,7 +21,7 @@
 
 import numpy as np
 from gnuradio import gr
-import code,math,pmt,time
+import code,math,pmt,time,threading
 
 class max_freq(gr.sync_block):
     """
@@ -39,12 +39,13 @@ class max_freq(gr.sync_block):
         self.snapto=round_to
         self.debug=debug
         self.last_station_indices=[0]*self.num_decoders
-	self.message_port_register_out(pmt.intern('out'))
-	self.timer=time.time()
-	self.message_port_register_in(pmt.intern('ctrl'))
-	self.set_msg_handler(pmt.intern('ctrl'), self.handle_ctrl_msg)
-	self.searchMode=True
-	self.index_fixed=[False]*self.num_decoders
+        self.message_port_register_out(pmt.intern('out'))
+        self.timer=time.time()
+        self.message_port_register_in(pmt.intern('ctrl'))
+        self.set_msg_handler(pmt.intern('ctrl'), self.handle_ctrl_msg)
+        self.searchMode=True
+        self.index_fixed=[False]*self.num_decoders
+        self.search_thread=None
     def freq_to_index(self,freq):
       startfreq=self.center_freq-self.samp_rate/2
       #freq=self.samp_rate*index/self.fft_len+startfreq
@@ -61,26 +62,26 @@ class max_freq(gr.sync_block):
       try:
         m = pmt.pmt_to_python.pmt_to_dict(msg)
         if m.has_key("cmd") and m["cmd"]=="set_audio_freq":
-	  #print(m)
-	  #print(self.last_station_indices)
-	  freq_index=self.freq_to_index(m["freq"])
-	  if m["chan"]=="left" and freq_index<self.fft_len-5:
-	    if self.last_station_indices[0]==freq_index:
-	      self.index_fixed[0]=False
-	      print("decoder 0 free")
-	    else:
-	      self.last_station_indices[0]=freq_index
-	      self.index_fixed[0]=True
-	      print("decoder 0 fixed to %i"%m["freq"])
-	  if m["chan"]=="right" and freq_index<self.fft_len-5:
-	    if self.last_station_indices[1]==freq_index:
-	      self.index_fixed[1]=False
-	      print("decoder 1 free")
-	    else:
-	      self.last_station_indices[1]=freq_index
-	      self.index_fixed[1]=True
-	      print("decoder 1 fixed to %i"%m["freq"])
-	  #print(self.last_station_indices)
+          #print(m)
+          #print(self.last_station_indices)
+          freq_index=self.freq_to_index(m["freq"])
+          if m["chan"]=="left" and freq_index<self.fft_len-5:
+            if self.last_station_indices[0]==freq_index:
+              self.index_fixed[0]=False
+              print("decoder 0 free")
+            else:
+              self.last_station_indices[0]=freq_index
+              self.index_fixed[0]=True
+              print("decoder 0 fixed to %i"%m["freq"])
+          if m["chan"]=="right" and freq_index<self.fft_len-5:
+            if self.last_station_indices[1]==freq_index:
+              self.index_fixed[1]=False
+              print("decoder 1 free")
+            else:
+              self.last_station_indices[1]=freq_index
+              self.index_fixed[1]=True
+              print("decoder 1 fixed to %i"%m["freq"])
+          #print(self.last_station_indices)
         if m.has_key("cmd") and m["cmd"]=="switch mode":
           self.searchMode=not self.searchMode
           print("searchMode: %s"%self.searchMode)
@@ -89,19 +90,14 @@ class max_freq(gr.sync_block):
     def set_center_freq(self, freq=None):
       self.index_fixed=[False]*self.num_decoders#free all decoders (freq wouldn't match anyways)
       if freq is not None:
-	      if isinstance(freq, float) or isinstance(freq, int):
-		      self.center_freq=freq
-	      else:
-		      self.center_freq = int(freq)
-    def work(self, input_items, output_items):
-      if time.time()-self.timer<2:#every 2 seconds
-	return len(input_items[0])
-      elif self.searchMode:
-      #in0 = input_items[0]
-      #ii=input_items
+              if isinstance(freq, float) or isinstance(freq, int):
+                      self.center_freq=freq
+              else:
+                      self.center_freq = int(freq)
+    def search(self,inputvector):
         carrier_width=2
         carrier=self.fft_len/2
-        numbers=np.delete(input_items[0][0],range(carrier-carrier_width,carrier+carrier_width+1))#read input and disregard center (hackrf LO)
+        numbers=np.delete(inputvector[0],range(carrier-carrier_width,carrier+carrier_width+1))#read input and disregard center (hackrf LO)
         #threshold=40# uni
         #threshold=60#home
         #threshold=np.mean(numbers)#2017-03-21 fft-multi-decoder
@@ -129,10 +125,10 @@ class max_freq(gr.sync_block):
 #        max_indices[0].append(0)#to detect last station
         max_indices=np.append(max_indices,0)#to detect last station
         #try:
-	 
+         
          #max_indices.remove(self.fft_len/2)#suppress local oscillator of hackrf
         #except ValueError:
-	  #pass
+          #pass
         for i in max_indices:
           if abs(i-last_index) <= fuzzyness:
             count+=i-last_index
@@ -178,26 +174,26 @@ class max_freq(gr.sync_block):
         new_stations=[]
         #add fixed stations (currently unused):
         for i,old_freq in enumerate(self.last_station_indices):
-	  if self.index_fixed[i]:
-	    station_indices_tune[i]=old_freq
+          if self.index_fixed[i]:
+            station_indices_tune[i]=old_freq
         #change existing/add new:
         for new_freq in station_indices_trunc:
-	  added=False
-	  for i,old_freq in enumerate(self.last_station_indices):
-	    if abs(old_freq-new_freq)<same_station_threshold:
-	      station_indices_tune[i]=new_freq
-	      added=True
-	  if not added:
-	    new_stations.append(new_freq)
-	#print("tune1:%s"%station_indices_tune)
-	if self.debug:
+          added=False
+          for i,old_freq in enumerate(self.last_station_indices):
+            if abs(old_freq-new_freq)<same_station_threshold:
+              station_indices_tune[i]=new_freq
+              added=True
+          if not added:
+            new_stations.append(new_freq)
+        #print("tune1:%s"%station_indices_tune)
+        if self.debug:
           print("tunc:%s"%station_indices_trunc)
-	  print("new_1:%s"%new_stations)
-	
-	for i,tune_freq in enumerate(station_indices_tune):
-	  if tune_freq == 0 and len(new_stations)>0:#add new stations to empty decoders
-	    station_indices_tune[i]=new_stations.pop()
-	#print("tune2:%s"%station_indices_tune)
+          print("new_1:%s"%new_stations)
+        
+        for i,tune_freq in enumerate(station_indices_tune):
+          if tune_freq == 0 and len(new_stations)>0:#add new stations to empty decoders
+            station_indices_tune[i]=new_stations.pop()
+        #print("tune2:%s"%station_indices_tune)
         
         if self.debug:
           print("new_2:%s"%new_stations)
@@ -216,19 +212,35 @@ class max_freq(gr.sync_block):
           station_freqs.append(round(freq,-num_decimals))
           station_strength.append(round(numbers[index],-2))
         for i in range(0,min(self.num_decoders,len(station_freqs))):
-	  msg_string=str(i+1)+" "+str(station_freqs[i])
-	  send_pmt = pmt.string_to_symbol(msg_string)
-	  self.message_port_pub(pmt.intern('out'), send_pmt)
-	if self.debug:
-	  #print(max_indices)
-	  #print(np.mean(numbers))
-	  #print(len(max_indices))
-	  #print(station_indices)
-	  #print(station_indices_grouped)
-	  #print(station_indices_sorted)
-	  #print(station_indices_tune)
-	  #print(station_strength)
-	  print(station_freqs)
+          msg_string=str(i+1)+" "+str(station_freqs[i])
+          send_pmt = pmt.string_to_symbol(msg_string)
+          self.message_port_pub(pmt.intern('out'), send_pmt)
+        if self.debug:
+          #print(max_indices)
+          #print(np.mean(numbers))
+          #print(len(max_indices))
+          #print(station_indices)
+          #print(station_indices_grouped)
+          #print(station_indices_sorted)
+          #print(station_indices_tune)
+          #print(station_strength)
+          print(station_freqs)      
+    def work(self, input_items, output_items):
+      if time.time()-self.timer<2:#every 2 seconds
+	return len(input_items[0])
+      elif self.searchMode:
+        inputvector=input_items[0]
+        if self.search_thread == None or self.search_thread.is_alive()==False:
+          if self.debug:
+            print("starting thread")
+          self.search_thread = threading.Thread(target=self.search, args=[inputvector], kwargs={})
+          self.search_thread.start()
+        elif self.debug:
+            print("thread exists")
+          
+      #in0 = input_items[0]
+      #ii=input_items
+
 
         return len(input_items[0])
       else:
diff --git a/python/tmc_classes.py b/python/tmc_classes.py
index 71e62f5..fc9a8b4 100644
--- a/python/tmc_classes.py
+++ b/python/tmc_classes.py
@@ -40,7 +40,7 @@ from collections import namedtuple
 #Street(name='test', lcn=12)
 #Street(lcn=12,name="test").name
 import threading
-#thr = threading.Thread(target=foo, args=(), kwargs={})
+#thr = threading.Thread(target=foo, args=(), kwargs={})#kwargs = keyword-arguments
 #thr.start() # will run "foo"
 #....
 #thr.is_alive() # will return whether foo is running currently