diff --git a/files/www/cgi-bin/signal b/files/www/cgi-bin/signal
index 79999758..8972a38e 100755
--- a/files/www/cgi-bin/signal
+++ b/files/www/cgi-bin/signal
@@ -121,7 +121,7 @@ $header = <<EOF;
                content += "Signal: N/A<br/>";
             }
             content += "Noise: " + e.entries[0].dataPoint.y[1] + "dBm<br/>";
-            content += "SNR: " + e.entries[0].dataPoint.m + "dBm<br/>";
+            content += "SNR: " + e.entries[0].dataPoint.m + "dB<br/>";
             content += "TX Rate: " + e.entries[0].dataPoint.tx_rate + "Mbps<br/>";
             content += "TX MCS: " + e.entries[0].dataPoint.tx_mcs + "<br/>";
             content += "RX Rate: " + e.entries[0].dataPoint.rx_rate + "Mbps<br/>";
@@ -144,7 +144,9 @@ $header = <<EOF;
         \$.getJSON("/cgi-bin/signal.json?device=$parms{device}", function (result) {
           chart.options.data[0].dataPoints = result[0];
           // chart.options.data[1].dataPoints = result[1];
-          chart.render();
+          if(result.constructor === Array) {
+            chart.render();
+          };
         });
       };
 
@@ -203,7 +205,7 @@ $parms{device}="" if(!/$parms{device}/ ~~ @files);
 
 # default to "Strongest Signal" for Realtime
 if(! $parms{device} and $parms{realtime}) {
-  $page = $page . "<option selected value='strongest'>Strongest Signal</option>";
+  $page = $page . "<option selected value='strongest'>Average signal for all connected stations</option>";
 }
 
 $firstSel=1;
diff --git a/files/www/cgi-bin/signal.json b/files/www/cgi-bin/signal.json
index 6cc6a2d7..2385134b 100755
--- a/files/www/cgi-bin/signal.json
+++ b/files/www/cgi-bin/signal.json
@@ -93,7 +93,7 @@ if parms.realtime then
     end
     -- get strongest signal
     s=iwinfo["nl80211"].signal(wifiiface)
-    m=tonumber(n)-tonumber(s)
+    m=tonumber(s)-tonumber(n)
     if s==0 then
       s="null"
     end
diff --git a/files/www/help.html b/files/www/help.html
index 737de1b2..e7acf566 100644
--- a/files/www/help.html
+++ b/files/www/help.html
@@ -102,7 +102,7 @@ name (if known) of the device accessing this page.
 <p>
 The right column contains the signal strength reading and other attributes of
 your node.  The <b>Signal/Noise/Ratio</b> is a reading of the strongest neighbor Mesh RF signal
-strength in dBm, and it is available only when the node is in a Mesh or Client
+strength (in dBm) from all connected stations, and it is available only when the node is in a Mesh or Client
 configuration.  The <strong>Auto</strong> button will take you to an
 automatically refreshing display of the current signal strength and an average
 of the last 20 readings. This is provided as an aid to assist in antenna
@@ -142,7 +142,7 @@ temporary files. Memory is the amount of RAM available for running processes.
 
 <br><br><hr>
 <a name=charts><h2>Charts Page</h2></a>
-<p>This page shows RF signal information in both a realtime and an archived view.  The default view shows the STRONGEST RF signal in realtime.<br>
+<p>This page shows RF signal information in both a realtime and an archived view.  The default view shows the Average signal of all connected stations in realtime.<br>
 	Below the node name, there will be a few control buttons:<br>
 	<ul>
 		<li><strong>Archive</strong>: takes you to the charts for any archived signal data on this node.</li>