diff --git a/samples/blackmiscdbus/servicetool.cpp b/samples/blackmiscdbus/servicetool.cpp
index d88e40fa7..3b0097bc5 100644
--- a/samples/blackmiscdbus/servicetool.cpp
+++ b/samples/blackmiscdbus/servicetool.cpp
@@ -255,7 +255,8 @@ namespace BlackMiscTest
         // on the client's side
         TestServiceInterface testserviceInterface(Testservice::ServiceName, Testservice::ServicePath, connection);
 
-        CSpeed speed(200, BlackMisc::PhysicalQuantities::CSpeedUnit::km_h());
+        CSpeed speed(200, CSpeedUnit::km_h());
+        CSpeed speedNull(0, CSpeedUnit::nullUnit());
         CAltitude al(1000, CAltitude::MeanSeaLevel, CLengthUnit::ft());
         QTextStream qtin(stdin);
         QString line;
@@ -289,7 +290,8 @@ namespace BlackMiscTest
             // PQs
             testserviceInterface.receiveSpeed(speed);
             qDebug() << "Send speed via interface" << speed;
-
+            testserviceInterface.receiveSpeed(speedNull);
+            qDebug() << "Send null speed via interface" << speedNull;
             speed.switchUnit(CSpeedUnit::kts());
             testserviceInterface.receiveSpeed(speed);
             qDebug() << "Send speed via interface" << speed;
@@ -367,8 +369,22 @@ namespace BlackMiscTest
             qDebug() << "Pinged ATC station via interface"
                      << ((station == stationReceived) ? "OK" : "ERROR!") << stationReceived;
 
+            CUser pingUser("223344", "Ping Me user");
+            CUser userReceived = testserviceInterface.pingUser(pingUser);
+            qDebug() << "Pinged user via interface"
+                     << ((userReceived == pingUser) ? "OK" : "ERROR!") << userReceived;
+
             CAircraftSituation situation;
+            CAircraftSituation situationReceived = testserviceInterface.pingSituation(situation);
+            qDebug() << "Pinged situation via interface"
+                     << ((situation == situationReceived) ? "OK" : "ERROR!") << situationReceived;
+
+            CTransponder transponderReceived = testserviceInterface.pingTransponder(transponder);
+            qDebug() << "Pinged transponder via interface"
+                     << ((transponderReceived == transponder) ? "OK" : "ERROR!") << transponderReceived;
+
             CAircraft aircraft(callsign, CUser("123456", "Joe Pilot"), situation);
+            aircraft.setTransponder(transponder);
             CAircraft aircraftReceived = testserviceInterface.pingAircraft(aircraft);
             qDebug() << "Pinged aircraft via interface"
                      << ((aircraft == aircraftReceived) ? "OK" : "ERROR!") << aircraftReceived;
diff --git a/samples/blackmiscdbus/testservice.cpp b/samples/blackmiscdbus/testservice.cpp
index d97821dac..7154fc034 100644
--- a/samples/blackmiscdbus/testservice.cpp
+++ b/samples/blackmiscdbus/testservice.cpp
@@ -300,6 +300,33 @@ namespace BlackMiscTest
         return altitude;
     }
 
+    /*
+     * Ping user
+     */
+    CUser Testservice::pingUser(const CUser &user)
+    {
+        qDebug() << "Pid:" << ServiceTool::getPid() << "ping user:" << user;
+        return user;
+    }
+
+    /*
+     * Ping situation
+     */
+    BlackMisc::Aviation::CAircraftSituation Testservice::pingSituation(const BlackMisc::Aviation::CAircraftSituation &situation)
+    {
+        qDebug() << "Pid:" << ServiceTool::getPid() << "ping situation:" << situation;
+        return situation;
+    }
+
+    /*
+     * Ping transponder
+     */
+    BlackMisc::Aviation::CTransponder Testservice::pingTransponder(const BlackMisc::Aviation::CTransponder &transponder)
+    {
+        qDebug() << "Pid:" << ServiceTool::getPid() << "ping transponder:" << transponder;
+        return transponder;
+    }
+
     /*
      * Ping ATC station
      */
diff --git a/samples/blackmiscdbus/testservice.h b/samples/blackmiscdbus/testservice.h
index 406f48ce0..79179d815 100644
--- a/samples/blackmiscdbus/testservice.h
+++ b/samples/blackmiscdbus/testservice.h
@@ -100,15 +100,24 @@ namespace BlackMiscTest
         //! Receive an value map
         void receiveValueMap(const BlackMisc::CPropertyIndexVariantMap &valueMap) const;
 
-        //! Receive speed
+        //! Ping speed
         BlackMisc::PhysicalQuantities::CSpeed pingSpeed(const BlackMisc::PhysicalQuantities::CSpeed &speed);
 
-        //! Receive altitude
+        //! Ping altitude
         BlackMisc::Aviation::CAltitude pingAltitude(const BlackMisc::Aviation::CAltitude &altitude);
 
+        //! Ping user
+        BlackMisc::Network::CUser pingUser(const BlackMisc::Network::CUser &user);
+
+        //! Ping situation
+        BlackMisc::Aviation::CAircraftSituation pingSituation(const BlackMisc::Aviation::CAircraftSituation &situation);
+
         //! Ping ATC station
         BlackMisc::Aviation::CAtcStation pingAtcStation(const BlackMisc::Aviation::CAtcStation &station);
 
+        //! Ping transponder
+        BlackMisc::Aviation::CTransponder pingTransponder(const BlackMisc::Aviation::CTransponder &transponder);
+
         //! Ping aircraft
         BlackMisc::Aviation::CAircraft pingAircraft(const BlackMisc::Aviation::CAircraft &aircraft);
 
diff --git a/samples/blackmiscdbus/testservice_interface.h b/samples/blackmiscdbus/testservice_interface.h
index f9f65b4c9..8b6034fe4 100644
--- a/samples/blackmiscdbus/testservice_interface.h
+++ b/samples/blackmiscdbus/testservice_interface.h
@@ -94,6 +94,27 @@ namespace BlackMiscTest
             return asyncCallWithArgumentList(QLatin1String("pingAltitude"), argumentList);
         }
 
+        inline QDBusPendingReply<BlackMisc::Aviation::CAircraftSituation> pingSituation(BlackMisc::Aviation::CAircraftSituation situation)
+        {
+            QList<QVariant> argumentList;
+            argumentList << QVariant::fromValue(situation);
+            return asyncCallWithArgumentList(QLatin1String("pingSituation"), argumentList);
+        }
+
+        inline QDBusPendingReply<BlackMisc::Network::CUser> pingUser(BlackMisc::Network::CUser user)
+        {
+            QList<QVariant> argumentList;
+            argumentList << QVariant::fromValue(user);
+            return asyncCallWithArgumentList(QLatin1String("pingUser"), argumentList);
+        }
+
+        inline QDBusPendingReply<BlackMisc::Aviation::CTransponder> pingTransponder(BlackMisc::Aviation::CTransponder transponder)
+        {
+            QList<QVariant> argumentList;
+            argumentList << QVariant::fromValue(transponder);
+            return asyncCallWithArgumentList(QLatin1String("pingTransponder"), argumentList);
+        }
+
         inline QDBusPendingReply<BlackMisc::Aviation::CAtcStation> pingAtcStation(BlackMisc::Aviation::CAtcStation station)
         {
             QList<QVariant> argumentList;
diff --git a/src/blackmisc/aviation/avionicsbase.h b/src/blackmisc/aviation/avionicsbase.h
index 305c75b01..8dd7e0476 100644
--- a/src/blackmisc/aviation/avionicsbase.h
+++ b/src/blackmisc/aviation/avionicsbase.h
@@ -15,7 +15,6 @@
 
 namespace BlackMisc
 {
-
     namespace Aviation
     {
 
@@ -29,43 +28,30 @@ namespace BlackMisc
             public Mixin::CompareByTuple<CAvionicsBase>,
             public Mixin::String<CAvionicsBase>
         {
-        protected:
-            QString m_name; //!< name of the unit
+        public:
+            //! Name
+            QString getName() const { return this->m_name; }
 
-            //! \brief Constructor
+            //! Are set values valid?
+            virtual bool validValues() const { return true; }
+
+        protected:
+            //! Constructor
             CAvionicsBase(const QString &name) : m_name(name) {}
 
-            //! Destructor
-            virtual ~CAvionicsBase() = default;
+            //! Set name
+            void setName(const QString &name) { this->m_name = name; }
 
-            //! \brief Set name
-            void setName(const QString &name)
-            {
-                this->m_name = name;
-            }
-
-        public:
             //! \copydoc CValueObject::convertToQString
             QString convertToQString(bool i18n = false) const { Q_UNUSED(i18n); return ""; }
 
-            //! \brief Name
-            QString getName() const
-            {
-                return this->m_name;
-            }
-
-            //! \brief Are set values valid?
-            virtual bool validValues() const
-            {
-                return true;
-            }
-
         private:
+            QString m_name; //!< name of the unit
             BLACK_ENABLE_TUPLE_CONVERSION(CAvionicsBase)
         };
 
-    }
-}
+    } // namespace
+} // namespace
 
 BLACK_DECLARE_TUPLE_CONVERSION(BlackMisc::Aviation::CAvionicsBase, (o.m_name))
 
diff --git a/src/blackmisc/aviation/comsystem.h b/src/blackmisc/aviation/comsystem.h
index 0c9155af6..df7489798 100644
--- a/src/blackmisc/aviation/comsystem.h
+++ b/src/blackmisc/aviation/comsystem.h
@@ -145,10 +145,8 @@ namespace BlackMisc
                 return isValidCivilAviationFrequency(f) || isValidMilitaryFrequency(f);
             }
 
-            /*!
-             * Round to channel spacing, set MHz as unit
-             * \see ChannelSpacing
-             */
+            //! Round to channel spacing, set MHz as unit
+            //! \see ChannelSpacing
             static void roundToChannelSpacing(BlackMisc::PhysicalQuantities::CFrequency &frequency, ChannelSpacing channelSpacing);
 
             //! Is compareFrequency within channel spacing of setFrequency
@@ -161,10 +159,8 @@ namespace BlackMisc
         private:
             ChannelSpacing m_channelSpacing = ChannelSpacing25KHz; //!< channel spacing
 
-            /*!
-             * Give me channel spacing in KHz
-             * \remarks Just a helper method, that is why no CFrequency is returned
-             */
+            //! Give me channel spacing in KHz
+            //! \remarks Just a helper method, that is why no CFrequency is returned
             static double channelSpacingToFrequencyKHz(ChannelSpacing channelSpacing);
 
             BLACK_ENABLE_TUPLE_CONVERSION(CComSystem)
diff --git a/src/blackmisc/aviation/modulator.cpp b/src/blackmisc/aviation/modulator.cpp
index dd3819d9e..4065c59c8 100644
--- a/src/blackmisc/aviation/modulator.cpp
+++ b/src/blackmisc/aviation/modulator.cpp
@@ -23,12 +23,6 @@ namespace BlackMisc
     namespace Aviation
     {
 
-        template <class AVIO>
-        bool CModulator<AVIO>::isDefaultValue() const
-        {
-            return (this->m_frequencyActive == FrequencyNotSet());
-        }
-
         template <class AVIO>
         void CModulator<AVIO>::toggleActiveStandby()
         {
@@ -37,66 +31,6 @@ namespace BlackMisc
             this->m_frequencyStandby = a;
         }
 
-        template <class AVIO>
-        BlackMisc::PhysicalQuantities::CFrequency CModulator<AVIO>::getFrequencyActive() const
-        {
-            return this->m_frequencyActive;
-        }
-
-        template <class AVIO>
-        BlackMisc::PhysicalQuantities::CFrequency CModulator<AVIO>::getFrequencyStandby() const
-        {
-            return this->m_frequencyStandby;
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setFrequencyActive(const BlackMisc::PhysicalQuantities::CFrequency &frequency)
-        {
-            this->m_frequencyActive = frequency;
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setFrequencyStandby(const BlackMisc::PhysicalQuantities::CFrequency &frequency)
-        {
-            this->m_frequencyStandby = frequency;
-        }
-
-        template <class AVIO>
-        qint32 CModulator<AVIO>::getVolumeOutput() const
-        {
-            return this->m_volumeOutput;
-        }
-
-        template <class AVIO>
-        qint32 CModulator<AVIO>::getVolumeInput() const
-        {
-            return this->m_volumeInput;
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setVolumeOutput(qint32 volume)
-        {
-            this->m_volumeOutput = volume;
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setVolumeInput(qint32 volume)
-        {
-            this->m_volumeInput = volume;
-        }
-
-        template <class AVIO>
-        bool CModulator<AVIO>::isEnabled() const
-        {
-            return this->m_enabled;
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setEnabled(bool enable)
-        {
-            this->m_enabled = enable;
-        }
-
         template <class AVIO>
         CVariant CModulator<AVIO>::propertyByIndex(const CPropertyIndex &index) const
         {
@@ -151,14 +85,6 @@ namespace BlackMisc
             }
         }
 
-        template <class AVIO>
-        CModulator<AVIO>::CModulator() :
-            CModulator::CValueObject("default") {}
-
-        template <class AVIO>
-        CModulator<AVIO>::CModulator(const QString &name, const BlackMisc::PhysicalQuantities::CFrequency &activeFrequency, const BlackMisc::PhysicalQuantities::CFrequency &standbyFrequency) :
-            CModulator::CValueObject(name), m_frequencyActive(activeFrequency), m_frequencyStandby(standbyFrequency) {}
-
         template <class AVIO>
         QString CModulator<AVIO>::convertToQString(bool i18n) const
         {
@@ -168,108 +94,6 @@ namespace BlackMisc
             return s;
         }
 
-        template <class AVIO>
-        void CModulator<AVIO>::setFrequencyActiveKHz(double frequencyKHz)
-        {
-            this->m_frequencyActive = BlackMisc::PhysicalQuantities::CFrequency(frequencyKHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::kHz());
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setFrequencyStandbyKHz(double frequencyKHz)
-        {
-            this->m_frequencyStandby = BlackMisc::PhysicalQuantities::CFrequency(frequencyKHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::kHz());
-        }
-
-
-        template <class AVIO>
-        void CModulator<AVIO>::setFrequencyActiveMHz(double frequencyMHz)
-        {
-            frequencyMHz = Math::CMathUtils::round(frequencyMHz, 3);
-            this->m_frequencyActive = BlackMisc::PhysicalQuantities::CFrequency(frequencyMHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::MHz());
-        }
-
-        template <class AVIO>
-        void CModulator<AVIO>::setFrequencyStandbyMHz(double frequencyMHz)
-        {
-            frequencyMHz = Math::CMathUtils::round(frequencyMHz, 3);
-            this->m_frequencyStandby = BlackMisc::PhysicalQuantities::CFrequency(frequencyMHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::MHz());
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameCom1()
-        {
-            static QString n("COM1");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameCom2()
-        {
-            static QString n("COM2");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameCom3()
-        {
-            static QString n("COM3");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameNav1()
-        {
-            static QString n("NAV1");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameNav2()
-        {
-            static QString n("NAV2");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameNav3()
-        {
-            static QString n("NAV3");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameAdf1()
-        {
-            static QString n("ADF1");
-            return n;
-        }
-
-        template <class AVIO>
-        const QString &CModulator<AVIO>::NameAdf2()
-        {
-            static QString n("ADF2");
-            return n;
-        }
-
-        template <class AVIO>
-        const BlackMisc::PhysicalQuantities::CFrequency &CModulator<AVIO>::FrequencyNotSet()
-        {
-            static BlackMisc::PhysicalQuantities::CFrequency f;
-            return f;
-        }
-
-        template <class AVIO>
-        AVIO const *CModulator<AVIO>::derived() const
-        {
-            return static_cast<AVIO const *>(this);
-        }
-
-        template <class AVIO>
-        AVIO *CModulator<AVIO>::derived()
-        {
-            return static_cast<AVIO *>(this);
-        }
-
         // see here for the reason of thess forward instantiations
         // http://www.parashift.com/c++-faq/separate-template-class-defn-from-decl.html
         template class CModulator<CComSystem>;
diff --git a/src/blackmisc/aviation/modulator.h b/src/blackmisc/aviation/modulator.h
index 4b004be50..f23cf0d96 100644
--- a/src/blackmisc/aviation/modulator.h
+++ b/src/blackmisc/aviation/modulator.h
@@ -22,10 +22,6 @@ namespace BlackMisc
     namespace Aviation
     {
 
-        class CComSystem;
-        class CNavSystem;
-        class CAdfSystem;
-
         //! Base class for COM, NAV, Squawk units.
         template <class AVIO> class CModulator : public CValueObject<CModulator<AVIO>, CAvionicsBase>
         {
@@ -41,126 +37,194 @@ namespace BlackMisc
             };
 
             //! Default value?
-            virtual bool isDefaultValue() const;
+            virtual bool isDefaultValue() const
+            {
+                return (this->m_frequencyActive == FrequencyNotSet());
+            }
 
             //! Toggle active and standby frequencies
             void toggleActiveStandby();
 
             //! Active frequency
-            BlackMisc::PhysicalQuantities::CFrequency getFrequencyActive() const;
+            BlackMisc::PhysicalQuantities::CFrequency getFrequencyActive() const
+            {
+                return this->m_frequencyActive;
+            }
 
             //! Standby frequency
-            BlackMisc::PhysicalQuantities::CFrequency getFrequencyStandby() const;
+            BlackMisc::PhysicalQuantities::CFrequency getFrequencyStandby() const
+            {
+                return this->m_frequencyStandby;
+            }
 
             //! Set active frequency
-            virtual void setFrequencyActive(const BlackMisc::PhysicalQuantities::CFrequency &frequency);
+            virtual void setFrequencyActive(const BlackMisc::PhysicalQuantities::CFrequency &frequency)
+            {
+                this->m_frequencyActive = frequency;
+            }
 
             //! Set standby frequency
-            virtual void setFrequencyStandby(const BlackMisc::PhysicalQuantities::CFrequency &frequency);
+            virtual void setFrequencyStandby(const BlackMisc::PhysicalQuantities::CFrequency &frequency)
+            {
+                this->m_frequencyStandby = frequency;
+            }
 
             //! Output volume 0..100
-            qint32 getVolumeOutput() const;
+            int getVolumeOutput() const { return this->m_volumeOutput; }
 
             //! Input volume 0..100
-            qint32 getVolumeInput() const;
+            int getVolumeInput() const { return this->m_volumeInput; }
 
             //! Output volume 0.100
-            void setVolumeOutput(qint32 volume);
+            void setVolumeOutput(int volume) { this->m_volumeOutput = volume; }
 
             //! Input volume 0..100
-            void setVolumeInput(qint32 volume);
+            void setVolumeInput(int volume) { this->m_volumeInput = volume; }
 
             //! Enabled?
-            bool isEnabled() const;
+            bool isEnabled() const { return this->m_enabled;}
 
             //! Enabled?
-            void setEnabled(bool enable);
+            void setEnabled(bool enable) { this->m_enabled = enable;}
 
             //! \copydoc CValueObject::propertyByIndex
-            CVariant propertyByIndex(const BlackMisc::CPropertyIndex &index) const;
+            virtual CVariant propertyByIndex(const BlackMisc::CPropertyIndex &index) const override;
 
             //! \copydoc CValueObject::setPropertyByIndex
-            void setPropertyByIndex(const CVariant &variant, const BlackMisc::CPropertyIndex &index);
-
-            //! \copydoc CValueObject::convertToQString
-            QString convertToQString(bool i18n = false) const;
+            virtual void setPropertyByIndex(const CVariant &variant, const BlackMisc::CPropertyIndex &index) override;
 
         protected:
             //! Default constructor
-            CModulator();
+            CModulator() : CModulator::CValueObject("default") {}
 
             //! Constructor
-            CModulator(const QString &name, const BlackMisc::PhysicalQuantities::CFrequency &activeFrequency, const BlackMisc::PhysicalQuantities::CFrequency &standbyFrequency);
+            CModulator(const QString &name, const BlackMisc::PhysicalQuantities::CFrequency &activeFrequency, const BlackMisc::PhysicalQuantities::CFrequency &standbyFrequency) :
+                CModulator::CValueObject(name), m_frequencyActive(activeFrequency), m_frequencyStandby(standbyFrequency) {}
+
+            //! \copydoc CValueObject::convertToQString
+            virtual QString convertToQString(bool i18n = false) const override;
 
             //! Set active frequency
-            void setFrequencyActiveKHz(double frequencyKHz);
+            void setFrequencyActiveKHz(double frequencyKHz)
+            {
+                this->m_frequencyActive = BlackMisc::PhysicalQuantities::CFrequency(frequencyKHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::kHz());
+            }
 
             //! Set standby frequency
-            void setFrequencyStandbyKHz(double frequencyKHz);
+            void setFrequencyStandbyKHz(double frequencyKHz)
+            {
+                this->m_frequencyStandby = BlackMisc::PhysicalQuantities::CFrequency(frequencyKHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::kHz());
+            }
 
             //! Set active frequency
-            virtual void setFrequencyActiveMHz(double frequencyMHz);
+            virtual void setFrequencyActiveMHz(double frequencyMHz)
+            {
+                frequencyMHz = Math::CMathUtils::round(frequencyMHz, 3);
+                this->m_frequencyActive = BlackMisc::PhysicalQuantities::CFrequency(frequencyMHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::MHz());
+            }
 
             //! Set standby frequency
-            virtual void setFrequencyStandbyMHz(double frequencyMHz);
+            virtual void setFrequencyStandbyMHz(double frequencyMHz)
+            {
+                frequencyMHz = Math::CMathUtils::round(frequencyMHz, 3);
+                this->m_frequencyStandby = BlackMisc::PhysicalQuantities::CFrequency(frequencyMHz, BlackMisc::PhysicalQuantities::CFrequencyUnit::MHz());
+            }
 
             //! COM1
-            static const QString &NameCom1();
+            static const QString &NameCom1()
+            {
+                static const QString n("COM1");
+                return n;
+            }
 
             //! COM2
-            static const QString &NameCom2();
+            static const QString &NameCom2()
+            {
+                static const QString n("COM2");
+                return n;
+            }
 
             //! COM3
-            static const QString &NameCom3();
+            static const QString &NameCom3()
+            {
+                static const QString n("COM3");
+                return n;
+            }
 
             //! NAV1
-            static const QString &NameNav1();
+            static const QString &NameNav1()
+            {
+                static const QString n("NAV1");
+                return n;
+            }
 
             //! NAV2
-            static const QString &NameNav2();
+            static const QString &NameNav2()
+            {
+                static const QString n("NAV2");
+                return n;
+            }
 
             //! NAV3
-            static const QString &NameNav3();
+            static const QString &NameNav3()
+            {
+                static const QString n("NAV3");
+                return n;
+            }
 
             //! ADF1
-            static const QString &NameAdf1();
+            static const QString &NameAdf1()
+            {
+                static QString n("ADF1");
+                return n;
+            }
 
             //! ADF2
-            static const QString &NameAdf2();
+            static const QString &NameAdf2()
+            {
+                static QString n("ADF2");
+                return n;
+            }
 
             //! Frequency not set
-            static const BlackMisc::PhysicalQuantities::CFrequency &FrequencyNotSet();
+            static const BlackMisc::PhysicalQuantities::CFrequency &FrequencyNotSet()
+            {
+                static const BlackMisc::PhysicalQuantities::CFrequency f(0, BlackMisc::PhysicalQuantities::CFrequencyUnit::nullUnit());
+                return f;
+            }
 
         private:
             BLACK_ENABLE_TUPLE_CONVERSION(CModulator)
             BlackMisc::PhysicalQuantities::CFrequency m_frequencyActive;  //!< active frequency
             BlackMisc::PhysicalQuantities::CFrequency m_frequencyStandby; //!< standby frequency
-            qint32 m_volumeInput = 0;  //!< volume input
-            qint32 m_volumeOutput = 0; //!< volume output
+            int m_volumeInput = 0;  //!< volume input
+            int m_volumeOutput = 0; //!< volume output
             bool m_enabled = true;     //!< is enabled, used e.g. for mute etc.
 
             //! Easy access to derived class (CRTP template parameter)
-            AVIO const *derived() const;
+            AVIO const *derived() const { return static_cast<AVIO const *>(this); }
 
             //! Easy access to derived class (CRTP template parameter)
-            AVIO *derived();
+            AVIO *derived() { return static_cast<AVIO *>(this); }
+
+			//! \cond PRIVATE
+			class CComSystem;
+			class CNavSystem;
+			class CAdfSystem;
+
+			extern template class BLACKMISC_EXPORT_TEMPLATE CModulator<CComSystem>;
+			extern template class BLACKMISC_EXPORT_TEMPLATE CModulator<CNavSystem>;
+			extern template class BLACKMISC_EXPORT_TEMPLATE CModulator<CAdfSystem>;
+			//! \endcond
         };
-
-        //! \cond PRIVATE
-        extern template class BLACKMISC_EXPORT_TEMPLATE CModulator<CComSystem>;
-        extern template class BLACKMISC_EXPORT_TEMPLATE CModulator<CNavSystem>;
-        extern template class BLACKMISC_EXPORT_TEMPLATE CModulator<CAdfSystem>;
-        //! \endcond
-
-    }
-}
+    } // namespace
+} // namespace
 
 BLACK_DECLARE_TUPLE_CONVERSION_TEMPLATE(BlackMisc::Aviation::CModulator, (
-                                            o.m_frequencyActive,
-                                            o.m_frequencyStandby,
-                                            o.m_volumeInput ,
-                                            o.m_volumeOutput,
-                                            o.m_enabled
-                                        ))
+        o.m_frequencyActive,
+        o.m_frequencyStandby,
+        o.m_volumeInput ,
+        o.m_volumeOutput,
+        o.m_enabled))
 
 #endif // guard