diff --git a/Aircraft/Instruments-3d/vor/vor.ac b/Aircraft/Instruments-3d/vor/vor.ac
index 4e4075109..a173ea771 100644
--- a/Aircraft/Instruments-3d/vor/vor.ac
+++ b/Aircraft/Instruments-3d/vor/vor.ac
@@ -1,8 +1,9 @@
 AC3Db
 MATERIAL "ac3dmat1" rgb 1 1 1  amb 0.2 0.2 0.2  emis 0 0 0  spec 0 0 0  shi 10  trans 0
+MATERIAL "ac3dmat12" rgb 0.267 0.267 0.267  amb 0.2 0.2 0.2  emis 0 0 0  spec 0.302 0.302 0.302  shi 10  trans 0
 MATERIAL "DefaultWhite" rgb 1 1 1  amb 1 1 1  emis 0.15 0.15 0.15  spec 0.5 0.5 0.5  shi 64  trans 0
 OBJECT world
-kids 8
+kids 9
 OBJECT poly
 name "GlidescopeNeedle"
 crease 45.000000
@@ -15,14 +16,14 @@ numvert 6
 -0.003005 0.000533 0.029784
 numsurf 2
 SURF 0x0
-mat 1
+mat 2
 refs 4
 0 0 0
 3 0 0
 4 0 0
 2 0 0
 SURF 0x0
-mat 1
+mat 2
 refs 4
 0 0 0
 2 0 0
@@ -41,14 +42,14 @@ numvert 6
 -0.003005 0.004974 -0.000532
 numsurf 2
 SURF 0x0
-mat 1
+mat 2
 refs 4
 0 0 0
 2 0 0
 5 0 0
 4 0 0
 SURF 0x0
-mat 1
+mat 2
 refs 4
 1 0 0
 4 0 0
@@ -68,14 +69,14 @@ numvert 6
 -0.004518 0 -0.04
 numsurf 2
 SURF 0x0
-mat 1
+mat 2
 refs 4
 0 0.966797 0.958984
 3 0.00976562 0.958984
 4 0.00976562 0.480469
 5 0.966797 0.480469
 SURF 0x0
-mat 1
+mat 2
 refs 4
 1 0.966797 0
 5 0.966797 0.480469
@@ -95,14 +96,14 @@ numvert 6
 -0.001596 0 -0.04
 numsurf 2
 SURF 0x0
-mat 1
+mat 2
 refs 4
 0 0.998047 1
 3 0 1
 4 0 0.5
 5 0.998047 0.5
 SURF 0x0
-mat 1
+mat 2
 refs 4
 1 0.998047 0
 5 0.998047 0.5
@@ -122,14 +123,14 @@ numvert 6
 0 0 -0.04
 numsurf 2
 SURF 0x0
-mat 1
+mat 2
 refs 4
 0 0.998047 1
 3 0 1
 4 0 0.5
 5 0.998047 0.5
 SURF 0x0
-mat 1
+mat 2
 refs 4
 1 0.998047 0
 5 0.998047 0.5
@@ -193,3 +194,201 @@ refs 4
 1 0.150411 0.0462088
 0 0.65189 0.0462088
 kids 0
+OBJECT poly
+name "disk"
+loc 0 -0.0308515 0.0268345
+crease 101.000000
+numvert 20
+0.01 0.00396059 0.00479285
+0.01 0.00606797 0.00108645
+0.01 0.00533608 -0.00312831
+0.01 0.00210739 -0.0058793
+0.01 -0.00210737 -0.0058793
+0.01 -0.00533607 -0.00312831
+0.01 -0.00606796 0.00108645
+0.01 9.31323e-09 0.00625662
+0.01 -0.00396058 0.00479285
+0 0 0.00625662
+0 0.00396058 0.00479285
+0 0.00606796 0.00108645
+0 0.00533608 -0.00312831
+0 0.00210739 -0.0058793
+0 -0.00210738 -0.0058793
+0 -0.00533607 -0.00312831
+0 -0.00606796 0.00108645
+0 -0.00396058 0.00479285
+0 0 0
+0.01 9.31323e-09 0
+numsurf 27
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+0 0.879385 0.826352
+7 1 0.5
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+1 0.573978 1
+0 0.879385 0.826352
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+2 0.226682 0.939693
+1 0.573978 1
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+3 0 0.673648
+2 0.226682 0.939693
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+4 0 0.326352
+3 0 0.673648
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+5 0.226682 0.0603074
+4 0 0.326352
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+6 0.573978 0
+5 0.226682 0.0603074
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+8 0.879385 0.173648
+6 0.573978 0
+SURF 0x10
+mat 1
+refs 3
+19 0.484454 0.5
+7 1 0.5
+8 0.879385 0.173648
+SURF 0x10
+mat 1
+refs 4
+7 0 0
+0 0 0
+10 0 0
+9 0 0
+SURF 0x10
+mat 1
+refs 4
+0 0 0
+1 0 0
+11 0 0
+10 0 0
+SURF 0x10
+mat 1
+refs 4
+1 0 0
+2 0 0
+12 0 0
+11 0 0
+SURF 0x10
+mat 1
+refs 4
+2 0 0
+3 0 0
+13 0 0
+12 0 0
+SURF 0x10
+mat 1
+refs 4
+3 0 0
+4 0 0
+14 0 0
+13 0 0
+SURF 0x10
+mat 1
+refs 4
+4 0 0
+5 0 0
+15 0 0
+14 0 0
+SURF 0x10
+mat 1
+refs 4
+5 0 0
+6 0 0
+16 0 0
+15 0 0
+SURF 0x10
+mat 1
+refs 4
+6 0 0
+8 0 0
+17 0 0
+16 0 0
+SURF 0x10
+mat 1
+refs 4
+8 0 0
+7 0 0
+9 0 0
+17 0 0
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+10 0.879385 0.826352
+9 1 0.5
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+11 0.573978 1
+10 0.879385 0.826352
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+12 0.226682 0.939693
+11 0.573978 1
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+13 0 0.673648
+12 0.226682 0.939693
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+14 0 0.326352
+13 0 0.673648
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+15 0.226682 0.0603074
+14 0 0.326352
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+16 0.573978 0
+15 0.226682 0.0603074
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+17 0.879385 0.173648
+16 0.573978 0
+SURF 0x10
+mat 1
+refs 3
+18 0.484454 0.5
+9 1 0.5
+17 0.879385 0.173648
+kids 0
diff --git a/Aircraft/Instruments/dme.xml b/Aircraft/Instruments/dme.xml
index 3bc80c03d..0cb466a48 100644
--- a/Aircraft/Instruments/dme.xml
+++ b/Aircraft/Instruments/dme.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.01"?>
 
 <!--
 Default DME instrument.
@@ -22,7 +22,14 @@ click.  Actions always modify the values of properties, either by
 adjusting them, toggling them, or swaping them with other
 properties' values.
 -->
-
+<!--
+Dave Perry added a check for dme voltage greater than 8.0 volts so
+that the dme text does not light up if there is no power supplied.
+This allows more realistic implementation of master switches or
+avionics master switches as is done in pa24-electrical.nas.  This
+change has no affect on the c172p since this voltage is 28 volts
+all the time in that electrical system.
+-->
 <PropertyList>
  <name>DME</name>
  <w-base>128</w-base>
@@ -59,9 +66,15 @@ properties' values.
 
    <layer>
     <condition>
-     <not>
-      <property>/instrumentation/dme/in-range</property>
-     </not>
+     <and>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+      <not>
+       <property>/instrumentation/dme/in-range</property>
+      </not>
+     </and>
     </condition>
     <name>display</name>
     <type>text</type>
@@ -81,13 +94,19 @@ properties' values.
    </layer>
 
    <layer>
-    <condition>
-     <greater-than>
-      <property>/instrumentation/dme/indicated-distance-nm</property>
-      <value type="double">999.99</value>
-     </greater-than>
-    </condition>
     <name>display</name>
+    <condition>
+     <and>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+      <greater-than>
+       <property>/instrumentation/dme/indicated-distance-nm</property>
+       <value type="double">999.99</value>
+      </greater-than>
+     </and>
+    </condition>
     <type>text</type>
     <font>led</font>
     <point-size>6</point-size>
@@ -106,6 +125,12 @@ properties' values.
 
    <layer>
     <name>display</name>
+     <condition>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+     </condition>
     <type>text</type>
     <font>led</font>
     <point-size>6</point-size>
@@ -136,6 +161,12 @@ properties' values.
 
   <layer>
    <name>ground speed towards station</name>
+     <condition>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+     </condition>
    <type>switch</type>
 
    <layer>
@@ -150,9 +181,15 @@ properties' values.
 
    <layer>
     <condition>
-     <not>
+     <and>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+      <not>
        <property>/instrumentation/dme/in-range</property>
-     </not>
+      </not>
+     </and>
     </condition>
     <name>display</name>
     <type>text</type>
@@ -173,10 +210,16 @@ properties' values.
 
    <layer>
     <condition>
+     <and>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
      <greater-than>
        <property>/instrumentation/dme/indicated-ground-speed-kt</property>
        <value type="double">999</value>
      </greater-than>
+     </and>
     </condition>
     <name>display</name>
     <type>text</type>
@@ -196,6 +239,12 @@ properties' values.
    </layer>
 
    <layer>
+     <condition>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+     </condition>
     <type>text</type>
     <font>led</font>
     <point-size>6</point-size>
@@ -237,9 +286,15 @@ properties' values.
 
    <layer>
     <condition>
+     <and>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
      <not>
       <property>/instrumentation/dme/in-range</property>
      </not>
+    </and>
     </condition>
     <name>display</name>
     <type>text</type>
@@ -260,10 +315,16 @@ properties' values.
 
    <layer>
     <condition>
+     <and>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
      <greater-than>
       <property>/instrumentation/dme/indicated-time-min</property>
       <value type="double">99</value>
      </greater-than>
+     </and>
     </condition>
     <name>display</name>
     <type>text</type>
@@ -283,6 +344,12 @@ properties' values.
    </layer>
 
    <layer>
+     <condition>
+      <greater-than>
+       <property>/systems/electrical/outputs/dme</property>
+       <value>8.0</value>
+      </greater-than>
+     </condition>
     <type>text</type>
     <font>led</font>
     <point-size>6</point-size>
diff --git a/Aircraft/Instruments/navcom-kx155.xml b/Aircraft/Instruments/navcom-kx155.xml
index c1bc35e21..92bd1cd22 100644
--- a/Aircraft/Instruments/navcom-kx155.xml
+++ b/Aircraft/Instruments/navcom-kx155.xml
@@ -24,6 +24,19 @@ adjusting them, toggling them, or swaping them with other
 properties' values.
 -->
 
+<!--
+2/10/06
+Dave Perry added a check for Nav/Com power, so the frequencies won't 
+light if
+/systems/electrical/outputs/nav is less than 8.0 volts. See the con-
+dition added for these text layers below. This allows a more realistic 
+master switch and avionics master switch implementation in the electrical 
+system model.  I also checked to make sure this does not negatively 
+impact the c172p. Had to add a property alias to the params after the 
+nav1.xml include in c172p-2d-panel.xml. Since the electrical system 
+for the c172p has this voltage at 28 volts, these changes have no 
+impact on the c172p.
+-->
 <PropertyList>
  
  <name>NavCom Radio</name>
@@ -37,6 +50,7 @@ properties' values.
   <nav-freq-standby-prop>/instrumentation/nav[0]/frequencies/standby-mhz</nav-freq-standby-prop>
   <nav-morse-id-volume-prop>/instrumentation/nav[0]/volume</nav-morse-id-volume-prop>
   <nav-morse-ident-toggle-prop>/instrumentation/nav[0]/ident</nav-morse-ident-toggle-prop>
+  <nav-com-pwr-volts-prop>/systems/electrical/outputs/nav[0]</nav-com-pwr-volts-prop>
  </params>
 
  <layers>
@@ -54,6 +68,12 @@ properties' values.
 
   <layer>
    <name>nav frequencies</name>
+   <condition>
+    <greater-than>
+     <property alias="../../../../../params/nav-com-pwr-volts-prop"/>
+     <value>8.0</value>
+    </greater-than>
+   </condition>
    <type>text</type>
    <font>led</font>
    <point-size>6.5</point-size>
@@ -88,6 +108,12 @@ properties' values.
 
   <layer>
    <name>com frequencies</name>
+   <condition>
+    <greater-than>
+     <property alias="../../../../../params/nav-com-pwr-volts-prop"/>
+     <value>8.0</value>
+    </greater-than>
+   </condition>
    <type>text</type>
    <font>led</font>
    <point-size>6.5</point-size>
diff --git a/Aircraft/c172p/Models/c172p-2d-panel.xml b/Aircraft/c172p/Models/c172p-2d-panel.xml
index 03fc206c8..ce4794c25 100644
--- a/Aircraft/c172p/Models/c172p-2d-panel.xml
+++ b/Aircraft/c172p/Models/c172p-2d-panel.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.01"?>
 
 <!--
 Legacy 2D instruments and actions for the 3D C172P cockpit.
@@ -202,6 +202,14 @@ Legacy 2D instruments and actions for the 3D C172P cockpit.
    <nav-heading-needle-deflection>/instrumentation/nav[1]/heading-needle-deflection</nav-heading-needle-deflection>
     <nav-has-gs-needle>/sim/instrument-options/nav[1]/has-gs-needle</nav-has-gs-needle>
     <nav-needles-pivot>/sim/instrument-options/nav[1]/needles-pivot</nav-needles-pivot>
+<!--  Dave Perry added a check for nav voltage in Aircraft/Instruments/navcom-kx155.xml
+which won't "light up" the radio frequencies if this voltage is less than 8.0 volts.
+This allows more realistic implementation of a master switch or an avionics master
+switch, as is done in pa24-electrical.nas.  Since the c172p has this voltage at 28 volts,
+this change has no affect on the c172p. The following param is required for this to
+work.
+--> 
+    <nav-com-pwr-volts-prop>/systems/electrical/outputs/nav[1]</nav-com-pwr-volts-prop>
   </params>
   <x>620</x>
   <y>100</y>