The range at bottom of frequency block wasn't updating with a change in frequency: correction in gnuradio-companion flowgraph
diff --git a/apps/airprobe_rtlsdr.grc b/apps/airprobe_rtlsdr.grc
index f244fa6..64e20a5 100644
--- a/apps/airprobe_rtlsdr.grc
+++ b/apps/airprobe_rtlsdr.grc
@@ -69,7 +69,7 @@
     <key>variable</key>
     <param>
       <key>id</key>
-      <value>SACCH</value>
+      <value>CHANNEL_UNKNOWN</value>
     </param>
     <param>
       <key>_enabled</key>
@@ -77,150 +77,15 @@
     </param>
     <param>
       <key>value</key>
-      <value>0x80</value>
-    </param>
-    <param>
-      <key>alias</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(1448, 11)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
       <value>0</value>
     </param>
-  </block>
-  <block>
-    <key>variable</key>
-    <param>
-      <key>id</key>
-      <value>SDCCH</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>6</value>
-    </param>
     <param>
       <key>alias</key>
       <value></value>
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(1368, 11)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
-      <value>0</value>
-    </param>
-  </block>
-  <block>
-    <key>variable</key>
-    <param>
-      <key>id</key>
-      <value>BCCH</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>1</value>
-    </param>
-    <param>
-      <key>alias</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(1008, 11)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
-      <value>0</value>
-    </param>
-  </block>
-  <block>
-    <key>variable</key>
-    <param>
-      <key>id</key>
-      <value>CCCH</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>2</value>
-    </param>
-    <param>
-      <key>alias</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(1080, 11)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
-      <value>0</value>
-    </param>
-  </block>
-  <block>
-    <key>variable</key>
-    <param>
-      <key>id</key>
-      <value>RACH</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>3</value>
-    </param>
-    <param>
-      <key>alias</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(1152, 11)</value>
-    </param>
-    <param>
-      <key>_rotation</key>
-      <value>0</value>
-    </param>
-  </block>
-  <block>
-    <key>variable</key>
-    <param>
-      <key>id</key>
-      <value>AGCH</value>
-    </param>
-    <param>
-      <key>_enabled</key>
-      <value>True</value>
-    </param>
-    <param>
-      <key>value</key>
-      <value>4</value>
-    </param>
-    <param>
-      <key>alias</key>
-      <value></value>
-    </param>
-    <param>
-      <key>_coordinate</key>
-      <value>(1224, 11)</value>
+      <value>(864, 11)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -258,7 +123,7 @@
     <key>variable</key>
     <param>
       <key>id</key>
-      <value>CHANNEL_UNKNOWN</value>
+      <value>AGCH</value>
     </param>
     <param>
       <key>_enabled</key>
@@ -266,7 +131,7 @@
     </param>
     <param>
       <key>value</key>
-      <value>0</value>
+      <value>4</value>
     </param>
     <param>
       <key>alias</key>
@@ -274,7 +139,142 @@
     </param>
     <param>
       <key>_coordinate</key>
-      <value>(864, 11)</value>
+      <value>(1224, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>RACH</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1152, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>CCCH</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1080, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>BCCH</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1008, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>SDCCH</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1368, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>SACCH</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0x80</value>
+    </param>
+    <param>
+      <key>alias</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1448, 11)</value>
     </param>
     <param>
       <key>_rotation</key>
@@ -3205,7 +3205,7 @@
     </param>
     <param>
       <key>fc</key>
-      <value>fc</value>
+      <value>fc_slider</value>
     </param>
     <param>
       <key>bw</key>