diff --git a/companion/src/helpers.cpp b/companion/src/helpers.cpp
index bb6e7da4c..62ced5a75 100644
--- a/companion/src/helpers.cpp
+++ b/companion/src/helpers.cpp
@@ -465,85 +465,6 @@ void Helpers::getFileComboBoxValue(QComboBox * b, char * dest, int length)
   }
 }
 
-void Helpers::addRawSourceItems(QStandardItemModel * itemModel, const RawSourceType & type, int count, const GeneralSettings * const generalSettings,
-                                const ModelData * const model, const int start)
-{
-  for (int i = start; i < start + count; i++) {
-    RawSource src = RawSource(type, i);
-    if (!src.isAvailable(model, generalSettings, getCurrentBoard()))
-      continue;
-
-    QStandardItem * modelItem = new QStandardItem(src.toString(model, generalSettings));
-    modelItem->setData(src.toValue(), Qt::UserRole);
-    itemModel->appendRow(modelItem);
-  }
-}
-
-QStandardItemModel * Helpers::getRawSourceItemModel(const GeneralSettings * const generalSettings, const ModelData * const model, unsigned int flags)
-{
-  QStandardItemModel * itemModel = new QStandardItemModel();
-  Boards board = Boards(getCurrentBoard());
-  Firmware * fw = getCurrentFirmware();
-
-  if (flags & POPULATE_NONE) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_NONE, 1, generalSettings, model);
-  }
-
-  if (flags & POPULATE_SCRIPT_OUTPUTS) {
-    for (int i=0; i < getCurrentFirmware()->getCapability(LuaScripts); i++) {
-      addRawSourceItems(itemModel, SOURCE_TYPE_LUA_OUTPUT, fw->getCapability(LuaOutputsPerScript), generalSettings, model, i * 16);
-    }
-  }
-
-  if (model && (flags & POPULATE_VIRTUAL_INPUTS)) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_VIRTUAL_INPUT, fw->getCapability(VirtualInputs), generalSettings, model);
-  }
-
-  if (flags & POPULATE_SOURCES) {
-    int totalSources = CPN_MAX_STICKS + board.getCapability(Board::Pots) + board.getCapability(Board::Sliders) +  board.getCapability(Board::MouseAnalogs);
-    addRawSourceItems(itemModel, SOURCE_TYPE_STICK, totalSources, generalSettings, model);
-    addRawSourceItems(itemModel, SOURCE_TYPE_ROTARY_ENCODER, fw->getCapability(RotaryEncoders), generalSettings, model);
-  }
-
-  if (flags & POPULATE_TRIMS) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_TRIM, board.getCapability(Board::NumTrims), generalSettings, model);
-  }
-
-  if (flags & POPULATE_SOURCES) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_MAX, 1, generalSettings, model);
-  }
-
-  if (flags & POPULATE_SWITCHES) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_SWITCH, board.getCapability(Board::Switches), generalSettings, model);
-    addRawSourceItems(itemModel, SOURCE_TYPE_CUSTOM_SWITCH, fw->getCapability(LogicalSwitches), generalSettings, model);
-  }
-
-  if (flags & POPULATE_SOURCES) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_CYC, CPN_MAX_CYC, generalSettings, model);
-    addRawSourceItems(itemModel, SOURCE_TYPE_PPM, fw->getCapability(TrainerInputs), generalSettings, model);
-    addRawSourceItems(itemModel, SOURCE_TYPE_CH, fw->getCapability(Outputs), generalSettings, model);
-  }
-
-  if (flags & POPULATE_TELEMETRY) {
-    int count = 0;
-    if (IS_ARM(board.getBoardType())) {
-      addRawSourceItems(itemModel, SOURCE_TYPE_SPECIAL, 5, generalSettings, model);
-      count = CPN_MAX_SENSORS * 3;
-    }
-    else {
-      count = ((flags & POPULATE_TELEMETRYEXT) ? TELEMETRY_SOURCES_STATUS_COUNT : TELEMETRY_SOURCES_COUNT);
-    }
-    if (model && count)
-      addRawSourceItems(itemModel, SOURCE_TYPE_TELEMETRY, count, generalSettings, model);
-  }
-
-  if (flags & POPULATE_GVARS) {
-    addRawSourceItems(itemModel, SOURCE_TYPE_GVAR, fw->getCapability(Gvars), generalSettings, model);
-  }
-
-  return itemModel;
-}
-
 void Helpers::exportAppSettings(QWidget * dlgParent)
 {
   static QString lastExpFile = CPN_SETTINGS_INI_PATH.arg(QDateTime::currentDateTime().toString("dd-MMM-yy"));
diff --git a/companion/src/helpers.h b/companion/src/helpers.h
index e1e404847..88fdb598c 100644
--- a/companion/src/helpers.h
+++ b/companion/src/helpers.h
@@ -117,26 +117,8 @@ class CurveGroup : public QObject {
     int lastType;
 };
 
-
-#define POPULATE_NONE           (1<<0)
-#define POPULATE_SOURCES        (1<<1)
-#define POPULATE_TRIMS          (1<<2)
-#define POPULATE_SWITCHES       (1<<3)
-#define POPULATE_GVARS          (1<<4)
-#define POPULATE_TELEMETRY      (1<<5)
-#define POPULATE_TELEMETRYEXT   (1<<6)
-#define POPULATE_VIRTUAL_INPUTS (1<<7)
-#define POPULATE_SCRIPT_OUTPUTS (1<<8)
-
-#define GVARS_VARIANT           0x0001
-#define FRSKY_VARIANT           0x0002
-
 namespace Helpers
 {
-  void addRawSourceItems(QStandardItemModel * itemModel, const RawSourceType & type, int count, const GeneralSettings * const generalSettings = NULL,
-                         const ModelData * const model = NULL, const int start = 0);
-  QStandardItemModel * getRawSourceItemModel(const GeneralSettings * const generalSettings = NULL, const ModelData * const model = NULL, unsigned int flags = 0);
-
   void populateGvarUseCB(QComboBox *b, unsigned int phase);
   void populateGVCB(QComboBox & b, int value, const ModelData & model);
   QString getAdjustmentString(int16_t val, const ModelData * model = NULL, bool sign = false);
diff --git a/companion/src/modeledit/customfunctions.cpp b/companion/src/modeledit/customfunctions.cpp
index 8852a5646..113403787 100644
--- a/companion/src/modeledit/customfunctions.cpp
+++ b/companion/src/modeledit/customfunctions.cpp
@@ -20,6 +20,7 @@
 
 #include "customfunctions.h"
 #include "switchitemmodel.h"
+#include "rawsourceitemmodel.h"
 #include "helpers.h"
 #include "appdata.h"
 
@@ -69,9 +70,6 @@ void RepeatComboBox::update()
 CustomFunctionsPanel::CustomFunctionsPanel(QWidget * parent, ModelData * model, GeneralSettings & generalSettings, Firmware * firmware):
   GenericPanel(parent, model, generalSettings, firmware),
   functions(model ? model->customFn : generalSettings.customFn),
-  rawSwitchItemModel(NULL),
-  rawSrcInputsItemModel(NULL),
-  rawSrcAllItemModel(NULL),
   mediaPlayerCurrent(-1),
   mediaPlayer(NULL)
 {
@@ -79,7 +77,10 @@ CustomFunctionsPanel::CustomFunctionsPanel(QWidget * parent, ModelData * model,
   lock = true;
   int num_fsw = model ? firmware->getCapability(CustomFunctions) : firmware->getCapability(GlobalFunctions);
 
-  setDataModels();
+  rawSwitchItemModel = new RawSwitchFilterItemModel(&generalSettings, model, model ? SpecialFunctionsContext : GlobalFunctionsContext);
+  rawSrcAllItemModel = new RawSourceFilterItemModel(&generalSettings, model, this);
+  rawSrcInputsItemModel = new RawSourceFilterItemModel(rawSrcAllItemModel->sourceModel(), RawSource::InputSourceGroups, this);
+  rawSrcGVarsItemModel = new RawSourceFilterItemModel(rawSrcAllItemModel->sourceModel(), RawSource::GVarsGroup, this);
 
   if (!firmware->getCapability(VoicesAsNumbers)) {
     tracksSet = getFilesSet(getSoundsPath(generalSettings), QStringList() << "*.wav" << "*.WAV", firmware->getCapability(VoicesMaxLength));
@@ -253,24 +254,13 @@ CustomFunctionsPanel::~CustomFunctionsPanel()
     stopSound(mediaPlayerCurrent);
 }
 
-void CustomFunctionsPanel::setDataModels()
+void CustomFunctionsPanel::updateDataModels()
 {
-  if (rawSwitchItemModel)
-    rawSwitchItemModel->update();
-  else
-    rawSwitchItemModel = new RawSwitchFilterItemModel(&generalSettings, model, model ? SpecialFunctionsContext : GlobalFunctionsContext);
-
-  // The RawSource item models have to be reloaded on every update().  TODO: convert to filtered model like for RawSwitches
-
-  if (rawSrcInputsItemModel)
-    rawSrcInputsItemModel->deleteLater();
-  if (rawSrcAllItemModel)
-    rawSrcAllItemModel->deleteLater();
-
-  rawSrcInputsItemModel = Helpers::getRawSourceItemModel(&generalSettings, model, POPULATE_NONE|POPULATE_SOURCES|POPULATE_VIRTUAL_INPUTS|POPULATE_TRIMS|POPULATE_SWITCHES);
-  rawSrcInputsItemModel->setParent(this);
-  rawSrcAllItemModel = Helpers::getRawSourceItemModel(&generalSettings, model, POPULATE_NONE|POPULATE_SOURCES|POPULATE_VIRTUAL_INPUTS|POPULATE_SWITCHES|POPULATE_GVARS|POPULATE_TRIMS|POPULATE_TELEMETRY|POPULATE_TELEMETRYEXT|POPULATE_SCRIPT_OUTPUTS);
-  rawSrcAllItemModel->setParent(this);
+  const bool oldLock = lock;
+  lock = true;
+  rawSwitchItemModel->update();
+  rawSrcAllItemModel->update();
+  lock = oldLock;
 }
 
 void CustomFunctionsPanel::onMediaPlayerStateChanged(QMediaPlayer::State state)
@@ -391,6 +381,7 @@ void CustomFunctionsPanel::refreshCustomFunction(int i, bool modified)
 
     unsigned int widgetsMask = 0;
     if (modified) {
+      const bool wasEmpty = cfn.isEmpty();
       cfn.swtch = RawSwitch(fswtchSwtch[i]->currentData().toInt());
       cfn.func = func;
       cfn.enabled = fswtchEnable[i]->isChecked();
@@ -603,8 +594,7 @@ void CustomFunctionsPanel::refreshCustomFunction(int i, bool modified)
 
 void CustomFunctionsPanel::update()
 {
-  setDataModels();
-
+  updateDataModels();
   lock = true;
   int num_fsw = model ? firmware->getCapability(CustomFunctions) : firmware->getCapability(GlobalFunctions);
   for (int i=0; i<num_fsw; i++) {
@@ -749,7 +739,7 @@ void CustomFunctionsPanel::populateFuncParamCB(QComboBox *b, uint function, unsi
         b->setCurrentIndex(b->findData(value));
         break;
       case 2:
-        b->setModel(Helpers::getRawSourceItemModel(&generalSettings, model, POPULATE_GVARS));
+        b->setModel(rawSrcGVarsItemModel);
         b->setCurrentIndex(b->findData(value));
         break;
     }
diff --git a/companion/src/modeledit/customfunctions.h b/companion/src/modeledit/customfunctions.h
index a7d3ca8da..26cb4b273 100644
--- a/companion/src/modeledit/customfunctions.h
+++ b/companion/src/modeledit/customfunctions.h
@@ -26,6 +26,7 @@
 
 #include <QMediaPlayer>
 
+class RawSourceFilterItemModel;
 class RawSwitchFilterItemModel;
 class TimerEdit;
 
@@ -61,7 +62,7 @@ class CustomFunctionsPanel : public GenericPanel
     CustomFunctionData * functions;
 
   private slots:
-    void setDataModels();
+    void updateDataModels();
     void customFunctionEdited();
     void functionEdited();
     void fsw_customContextMenuRequested(QPoint pos);
@@ -82,8 +83,9 @@ class CustomFunctionsPanel : public GenericPanel
     void populateGVmodeCB(QComboBox *b, unsigned int value);
     void populateFuncParamCB(QComboBox *b, uint function, unsigned int value, unsigned int adjustmode=0);
     RawSwitchFilterItemModel * rawSwitchItemModel;
-    QStandardItemModel * rawSrcInputsItemModel;
-    QStandardItemModel * rawSrcAllItemModel;
+    RawSourceFilterItemModel * rawSrcAllItemModel;
+    RawSourceFilterItemModel * rawSrcInputsItemModel;
+    RawSourceFilterItemModel * rawSrcGVarsItemModel;
 
     QSet<QString> tracksSet;
     QSet<QString> scriptsSet;
diff --git a/companion/src/modeledit/expodialog.cpp b/companion/src/modeledit/expodialog.cpp
index 5d3746e79..6e2a41ce8 100644
--- a/companion/src/modeledit/expodialog.cpp
+++ b/companion/src/modeledit/expodialog.cpp
@@ -21,6 +21,7 @@
 #include "expodialog.h"
 #include "ui_expodialog.h"
 #include "switchitemmodel.h"
+#include "rawsourceitemmodel.h"
 #include "helpers.h"
 
 ExpoDialog::ExpoDialog(QWidget *parent, ModelData & model, ExpoData *expoData, GeneralSettings & generalSettings,
@@ -93,7 +94,7 @@ ExpoDialog::ExpoDialog(QWidget *parent, ModelData & model, ExpoData *expoData, G
 
   if (firmware->getCapability(VirtualInputs)) {
     ui->inputName->setMaxLength(firmware->getCapability(InputsLength));
-    ui->sourceCB->setModel(Helpers::getRawSourceItemModel(&generalSettings, &model, POPULATE_NONE | POPULATE_SOURCES | POPULATE_SWITCHES | POPULATE_TRIMS | POPULATE_TELEMETRY));
+    ui->sourceCB->setModel(new RawSourceFilterItemModel(&generalSettings, &model, (RawSource::InputSourceGroups & ~RawSource::InputsGroup) | RawSource::TelemGroup, this));
     ui->sourceCB->setCurrentIndex(ui->sourceCB->findData(ed->srcRaw.toValue()));
     ui->sourceCB->removeItem(0);
     ui->inputName->setValidator(new QRegExpValidator(rx, this));
diff --git a/companion/src/modeledit/heli.cpp b/companion/src/modeledit/heli.cpp
index bc8fd74fc..fb70d081a 100644
--- a/companion/src/modeledit/heli.cpp
+++ b/companion/src/modeledit/heli.cpp
@@ -21,15 +21,15 @@
 #include "heli.h"
 #include "ui_heli.h"
 #include "helpers.h"
+#include "rawsourceitemmodel.h"
 
 HeliPanel::HeliPanel(QWidget *parent, ModelData & model, GeneralSettings & generalSettings, Firmware * firmware):
   ModelPanel(parent, model, generalSettings, firmware),
-  ui(new Ui::Heli),
-  rawSourceItemModel(nullptr)
+  ui(new Ui::Heli)
 {
   ui->setupUi(this);
 
-  setDataModels();
+  rawSourceItemModel = new RawSourceFilterItemModel(&generalSettings, &model, RawSource::InputSourceGroups, this);
 
   connect(ui->swashType, SIGNAL(currentIndexChanged(int)), this, SLOT(edited()));
   connect(ui->swashRingVal, SIGNAL(editingFinished()), this, SLOT(edited()));
@@ -66,19 +66,18 @@ HeliPanel::~HeliPanel()
   delete ui;
 }
 
-void HeliPanel::setDataModels()
+void HeliPanel::updateDataModels()
 {
-  if (rawSourceItemModel)
-    rawSourceItemModel->deleteLater();
-
-  rawSourceItemModel = Helpers::getRawSourceItemModel(&generalSettings, model, POPULATE_NONE | POPULATE_SOURCES | POPULATE_VIRTUAL_INPUTS | POPULATE_SWITCHES | POPULATE_TRIMS);
-  rawSourceItemModel->setParent(this);
+  const bool oldLock = lock;
+  lock = true;
+  rawSourceItemModel->update();
+  lock = oldLock;
 }
 
 void HeliPanel::update()
 {
   lock = true;
-  setDataModels();
+  updateDataModels();
 
   ui->swashType->setCurrentIndex(model->swashRingData.type);
   ui->swashCollectiveSource->setModel(rawSourceItemModel);
diff --git a/companion/src/modeledit/heli.h b/companion/src/modeledit/heli.h
index 6944fcafe..5a27c7c26 100644
--- a/companion/src/modeledit/heli.h
+++ b/companion/src/modeledit/heli.h
@@ -23,6 +23,8 @@
 
 #include "modeledit.h"
 
+class RawSourceFilterItemModel;
+
 namespace Ui {
   class Heli;
 }
@@ -37,12 +39,12 @@ class HeliPanel : public ModelPanel
     void update();
 
   private slots:
-    void setDataModels();
+    void updateDataModels();
     void edited();
 
   private:
     Ui::Heli *ui;
-    QStandardItemModel * rawSourceItemModel;
+    RawSourceFilterItemModel * rawSourceItemModel;
 };
 
 #endif // _HELI_H_
diff --git a/companion/src/modeledit/logicalswitches.cpp b/companion/src/modeledit/logicalswitches.cpp
index cc2394554..c060cfb95 100644
--- a/companion/src/modeledit/logicalswitches.cpp
+++ b/companion/src/modeledit/logicalswitches.cpp
@@ -20,21 +20,21 @@
 
 #include "logicalswitches.h"
 #include "switchitemmodel.h"
+#include "rawsourceitemmodel.h"
 #include "helpers.h"
 
 #include <TimerEdit>
 
 LogicalSwitchesPanel::LogicalSwitchesPanel(QWidget * parent, ModelData & model, GeneralSettings & generalSettings, Firmware * firmware):
   ModelPanel(parent, model, generalSettings, firmware),
-  rawSourceItemModel(NULL),
   selectedSwitch(0)
 {
   Stopwatch s1("LogicalSwitchesPanel");
 
-  int channelsMax = model.getChannelsMax(true);
   rawSwitchItemModel = new RawSwitchFilterItemModel(&generalSettings, &model, LogicalSwitchesContext);
 
-  setDataModels();
+  const unsigned srcGroups = firmware->getCapability(GvarsInCS) ? RawSource::AllSourceGroups : (RawSource::AllSourceGroups & ~RawSource::GVarsGroup);
+  rawSourceItemModel = new RawSourceFilterItemModel(&generalSettings, &model, srcGroups, this);
 
   QStringList headerLabels;
   headerLabels << "#" << tr("Function") << tr("V1") << tr("V2") << tr("AND Switch");
@@ -45,6 +45,8 @@ LogicalSwitchesPanel::LogicalSwitchesPanel(QWidget * parent, ModelData & model,
 
   s1.report("header");
 
+  const int channelsMax = model.getChannelsMax(true);
+
   lock = true;
   for (int i=0; i<firmware->getCapability(LogicalSwitches); i++) {
     // The label
@@ -161,14 +163,13 @@ LogicalSwitchesPanel::~LogicalSwitchesPanel()
 {
 }
 
-void LogicalSwitchesPanel::setDataModels()
+void LogicalSwitchesPanel::updateDataModels()
 {
-  if (rawSourceItemModel)
-    rawSourceItemModel->deleteLater();
-
-  int srcFlags =  POPULATE_NONE | POPULATE_SOURCES | POPULATE_SCRIPT_OUTPUTS | POPULATE_VIRTUAL_INPUTS | POPULATE_TRIMS | POPULATE_SWITCHES | POPULATE_TELEMETRY | (firmware->getCapability(GvarsInCS) ? POPULATE_GVARS : 0);
-  rawSourceItemModel = Helpers::getRawSourceItemModel(&generalSettings, model, srcFlags);
-  rawSourceItemModel->setParent(this);
+  const bool oldLock = lock;
+  lock = true;
+  rawSwitchItemModel->update();
+  rawSourceItemModel->update();
+  lock = oldLock;
 }
 
 void LogicalSwitchesPanel::functionChanged()
@@ -179,6 +180,7 @@ void LogicalSwitchesPanel::functionChanged()
   if (model->logicalSw[i].func == newFunc)
     return;
 
+  const unsigned oldFunc = model->logicalSw[i].func;
   CSFunctionFamily oldFuncFamily = model->logicalSw[i].getFunctionFamily();
   model->logicalSw[i].func = newFunc;
   CSFunctionFamily newFuncFamily = model->logicalSw[i].getFunctionFamily();
@@ -194,7 +196,11 @@ void LogicalSwitchesPanel::functionChanged()
       model->logicalSw[i].val2 = -129;
     }
   }
-  update();
+  if (bool(oldFunc) != bool(newFunc))
+    update();
+  else
+    updateLine(i);
+
   emit modified();
 }
 
@@ -435,7 +441,6 @@ void LogicalSwitchesPanel::updateLine(int i)
       cswitchDelay[i]->setValue(model->logicalSw[i].delay/10.0);
   }
 
-  rawSwitchItemModel->update();
   lock = false;
 }
 
@@ -508,7 +513,7 @@ void LogicalSwitchesPanel::populateAndSwitchCB(QComboBox *b)
 
 void LogicalSwitchesPanel::update()
 {
-  setDataModels();
+  updateDataModels();
   for (int i=0; i<firmware->getCapability(LogicalSwitches); i++) {
     updateLine(i);
   }
diff --git a/companion/src/modeledit/logicalswitches.h b/companion/src/modeledit/logicalswitches.h
index 0fed61bfa..fde3df0f4 100644
--- a/companion/src/modeledit/logicalswitches.h
+++ b/companion/src/modeledit/logicalswitches.h
@@ -25,6 +25,7 @@
 #include "radiodata.h"
 
 class RawSwitchFilterItemModel;
+class RawSourceFilterItemModel;
 class TimerEdit;
 
 class LogicalSwitchesPanel : public ModelPanel
@@ -38,7 +39,7 @@ class LogicalSwitchesPanel : public ModelPanel
     virtual void update();
 
   private slots:
-    void setDataModels();
+    void updateDataModels();
     void functionChanged();
     void v1Edited(int value);
     void v2Edited(int value);
@@ -66,7 +67,7 @@ class LogicalSwitchesPanel : public ModelPanel
     QComboBox * cswitchSource1[CPN_MAX_LOGICAL_SWITCHES];
     QComboBox * cswitchSource2[CPN_MAX_LOGICAL_SWITCHES];
     RawSwitchFilterItemModel * rawSwitchItemModel;
-    QStandardItemModel * rawSourceItemModel;
+    RawSourceFilterItemModel * rawSourceItemModel;
     int selectedSwitch;
 
     void populateCSWCB(QComboBox *b);
diff --git a/companion/src/modeledit/mixerdialog.cpp b/companion/src/modeledit/mixerdialog.cpp
index afcfb4754..0a424087f 100644
--- a/companion/src/modeledit/mixerdialog.cpp
+++ b/companion/src/modeledit/mixerdialog.cpp
@@ -22,6 +22,7 @@
 #include "ui_mixerdialog.h"
 #include "radiodata.h"
 #include "switchitemmodel.h"
+#include "rawsourceitemmodel.h"
 #include "helpers.h"
 
 MixerDialog::MixerDialog(QWidget *parent, ModelData & model, MixData * mixdata, GeneralSettings & generalSettings, Firmware * firmware) :
@@ -43,7 +44,7 @@ MixerDialog::MixerDialog(QWidget *parent, ModelData & model, MixData * mixdata,
 
   this->setWindowTitle(tr("DEST -> %1").arg(RawSource(SOURCE_TYPE_CH, md->destCh-1).toString(&model, &generalSettings)));
 
-  ui->sourceCB->setModel(Helpers::getRawSourceItemModel(&generalSettings, &model, POPULATE_NONE | POPULATE_SOURCES | POPULATE_SCRIPT_OUTPUTS | POPULATE_VIRTUAL_INPUTS | POPULATE_SWITCHES | POPULATE_TRIMS));
+  ui->sourceCB->setModel(new RawSourceFilterItemModel(&generalSettings, &model, RawSource::InputSourceGroups | RawSource::ScriptsGroup, this));
   ui->sourceCB->setCurrentIndex(ui->sourceCB->findData(md->srcRaw.toValue()));
   ui->sourceCB->removeItem(0);
 
diff --git a/companion/src/modeledit/telemetry.cpp b/companion/src/modeledit/telemetry.cpp
index c9a0d5c2a..3a0cdc0d9 100644
--- a/companion/src/modeledit/telemetry.cpp
+++ b/companion/src/modeledit/telemetry.cpp
@@ -25,6 +25,7 @@
 #include "ui_telemetry_sensor.h"
 #include "helpers.h"
 #include "appdata.h"
+#include "rawsourceitemmodel.h"
 
 #include <TimerEdit>
 
@@ -316,10 +317,11 @@ TelemetryAnalog::~TelemetryAnalog()
 
 /******************************************************/
 
-TelemetryCustomScreen::TelemetryCustomScreen(QWidget *parent, ModelData & model, FrSkyScreenData & screen, GeneralSettings & generalSettings, Firmware * firmware):
+TelemetryCustomScreen::TelemetryCustomScreen(QWidget *parent, ModelData & model, FrSkyScreenData & screen, GeneralSettings & generalSettings, Firmware * firmware, RawSourceFilterItemModel * srcModel):
   ModelPanel(parent, model, generalSettings, firmware),
   ui(new Ui::TelemetryCustomScreen),
-  screen(screen)
+  screen(screen),
+  rawSourceItemModel(srcModel)
 {
   ui->setupUi(this);
 
@@ -327,15 +329,17 @@ TelemetryCustomScreen::TelemetryCustomScreen(QWidget *parent, ModelData & model,
     for (int c=0; c<firmware->getCapability(TelemetryCustomScreensFieldsPerLine); c++) {
       fieldsCB[l][c] = new QComboBox(this);
       fieldsCB[l][c]->setProperty("index", c + (l<<8));
+      fieldsCB[l][c]->setModel(rawSourceItemModel);
       ui->screenNumsLayout->addWidget(fieldsCB[l][c], l, c, 1, 1);
-      connect(fieldsCB[l][c], SIGNAL(currentIndexChanged(int)), this, SLOT(customFieldChanged(int)));
+      connect(fieldsCB[l][c], SIGNAL(activated(int)), this, SLOT(customFieldChanged(int)));
     }
   }
 
   for (int l=0; l<4; l++) {
     barsCB[l] = new QComboBox(this);
     barsCB[l]->setProperty("index", l);
-    connect(barsCB[l], SIGNAL(currentIndexChanged(int)), this, SLOT(barSourceChanged(int)));
+    barsCB[l]->setModel(rawSourceItemModel);
+    connect(barsCB[l], SIGNAL(activated(int)), this, SLOT(barSourceChanged(int)));
     ui->screenBarsLayout->addWidget(barsCB[l], l, 0, 1, 1);
 
     minSB[l] = new QDoubleSpinBox(this);
@@ -393,19 +397,6 @@ TelemetryCustomScreen::TelemetryCustomScreen(QWidget *parent, ModelData & model,
   update();
 }
 
-void TelemetryCustomScreen::populateTelemetrySourceCB(QComboBox * b, RawSource & source, bool last)
-{
-  int flags = POPULATE_NONE | POPULATE_TELEMETRY;
-  if (IS_ARM(firmware->getBoard())) {
-    flags |= POPULATE_SOURCES | POPULATE_SCRIPT_OUTPUTS | POPULATE_VIRTUAL_INPUTS | POPULATE_TRIMS | POPULATE_SWITCHES | (firmware->getCapability(GvarsInCS) ? POPULATE_GVARS : 0);
-  }
-  else if (last) {
-    flags |= POPULATE_TELEMETRYEXT;
-  }
-  b->setModel(Helpers::getRawSourceItemModel(&generalSettings, model, flags));
-  b->setCurrentIndex(b->findData(source.toValue()));
-}
-
 TelemetryCustomScreen::~TelemetryCustomScreen()
 {
   delete ui;
@@ -421,12 +412,12 @@ void TelemetryCustomScreen::update()
 
   for (int l=0; l<4; l++) {
     for (int c=0; c<firmware->getCapability(TelemetryCustomScreensFieldsPerLine); c++) {
-      populateTelemetrySourceCB(fieldsCB[l][c], screen.body.lines[l].source[c], l==3);
+      fieldsCB[l][c]->setCurrentIndex(fieldsCB[l][c]->findData(screen.body.lines[l].source[c].toValue()));
     }
   }
 
   for (int l=0; l<4; l++) {
-    populateTelemetrySourceCB(barsCB[l], screen.body.bars[l].source);
+    barsCB[l]->setCurrentIndex(barsCB[l]->findData(screen.body.bars[l].source.toValue()));
   }
 
   if (screen.type == TELEMETRY_SCREEN_BARS) {
@@ -526,24 +517,36 @@ void TelemetryCustomScreen::scriptNameEdited()
 
 void TelemetryCustomScreen::customFieldChanged(int value)
 {
-  if (!lock) {
-    int index = sender()->property("index").toInt();
-    screen.body.lines[index/256].source[index%256] = RawSource(((QComboBox *)sender())->itemData(value).toInt());
+  if (lock || !sender() || !qobject_cast<QComboBox *>(sender()))
+    return;
+
+  bool ok;
+  const int index = sender()->property("index").toInt(&ok),
+      i = index / 256,
+      m = index % 256;
+  const RawSource src(qobject_cast<QComboBox *>(sender())->itemData(value).toInt());
+  if (ok && screen.body.lines[i].source[m].toValue() != src.toValue()) {
+    screen.body.lines[i].source[m] = src;
     emit modified();
   }
 }
 
 void TelemetryCustomScreen::barSourceChanged(int value)
 {
-  if (!lock) {
-    QComboBox * cb = qobject_cast<QComboBox*>(sender());
-    int index = cb->property("index").toInt();
-    screen.body.bars[index].source = RawSource(((QComboBox *)sender())->itemData(value).toInt());
-    screen.body.bars[index].barMin = 0;
-    screen.body.bars[index].barMax = 0;
-    updateBar(index);
-    emit modified();
-  }
+  if (lock || !sender() || !qobject_cast<QComboBox *>(sender()))
+    return;
+
+  bool ok;
+  const int index = sender()->property("index").toInt(&ok);
+  const RawSource src(qobject_cast<QComboBox *>(sender())->itemData(value).toInt());
+  if (!ok || screen.body.bars[index].source.toValue() == src.toValue())
+    return;
+
+  screen.body.bars[index].source = src;
+  screen.body.bars[index].barMin = 0;
+  screen.body.bars[index].barMax = 0;
+  updateBar(index);
+  emit modified();
 }
 
 void TelemetryCustomScreen::barMinChanged(double value)
@@ -854,11 +857,15 @@ TelemetryPanel::TelemetryPanel(QWidget *parent, ModelData & model, GeneralSettin
     ui->topbarGB->hide();
   }
 
+  RawSourceFilterItemModel * srcModel = (new RawSourceFilterItemModel(&generalSettings, &model, this));
+  connect(this, &TelemetryPanel::updated, srcModel, &RawSourceFilterItemModel::update);
+
   for (int i=0; i<firmware->getCapability(TelemetryCustomScreens); i++) {
-    TelemetryCustomScreen * tab = new TelemetryCustomScreen(this, model, model.frsky.screens[i], generalSettings, firmware);
+    TelemetryCustomScreen * tab = new TelemetryCustomScreen(this, model, model.frsky.screens[i], generalSettings, firmware, srcModel);
     ui->customScreens->addTab(tab, tr("Telemetry screen %1").arg(i+1));
     telemetryCustomScreens[i] = tab;
-    connect(tab, SIGNAL(modified()), this, SLOT(onModified()));
+    connect(tab, &TelemetryCustomScreen::modified, this, &TelemetryPanel::onModified);
+    connect(this, &TelemetryPanel::updated, tab, &TelemetryCustomScreen::update);
   }
 
   disableMouseScrolling();
@@ -891,10 +898,9 @@ void TelemetryPanel::update()
     for (int i=0; i<CPN_MAX_SENSORS; ++i) {
       sensorPanels[i]->update();
     }
-    for (int i=0; i<firmware->getCapability(TelemetryCustomScreens); i++) {
-      telemetryCustomScreens[i]->update();
-    }
   }
+
+  emit updated();
 }
 
 void TelemetryPanel::setup()
diff --git a/companion/src/modeledit/telemetry.h b/companion/src/modeledit/telemetry.h
index 09758d38b..a69b27e27 100644
--- a/companion/src/modeledit/telemetry.h
+++ b/companion/src/modeledit/telemetry.h
@@ -25,6 +25,7 @@
 #include "eeprominterface.h"
 
 class AutoComboBox;
+class RawSourceFilterItemModel;
 class TimerEdit;
 
 namespace Ui {
@@ -72,7 +73,7 @@ class TelemetryCustomScreen: public ModelPanel
     Q_OBJECT
 
   public:
-    TelemetryCustomScreen(QWidget *parent, ModelData & model, FrSkyScreenData & screen, GeneralSettings & generalSettings, Firmware * firmware);
+    TelemetryCustomScreen(QWidget *parent, ModelData & model, FrSkyScreenData & screen, GeneralSettings & generalSettings, Firmware * firmware, RawSourceFilterItemModel * srcModel);
     ~TelemetryCustomScreen();
     void update();
 
@@ -85,13 +86,11 @@ class TelemetryCustomScreen: public ModelPanel
     void barMaxChanged(double value);
     void barTimeChanged();
 
-  protected:
-    void populateTelemetrySourceCB(QComboBox * b, RawSource & source, bool last=false);
-
   private:
     void updateBar(int line);
     Ui::TelemetryCustomScreen * ui;
     FrSkyScreenData & screen;
+    RawSourceFilterItemModel * rawSourceItemModel;
     QComboBox * fieldsCB[4][3];
     QComboBox * barsCB[4];
     QDoubleSpinBox * minSB[4];
@@ -137,6 +136,9 @@ class TelemetryPanel : public ModelPanel
     virtual ~TelemetryPanel();
     virtual void update();
 
+  signals:
+    void updated();
+
   private slots:
     void on_telemetryProtocol_currentIndexChanged(int index);
     void onModified();