diff --git a/MMDVMHost.cpp b/MMDVMHost.cpp
index 5d0e84e..b68ea4e 100644
--- a/MMDVMHost.cpp
+++ b/MMDVMHost.cpp
@@ -604,7 +604,10 @@ void CMMDVMHost::setMode(unsigned char mode, bool logging)
 		if (m_dstarNetwork != NULL)
 			m_dstarNetwork->enable(false);
 		m_display->setDMR();
-		m_modem->writeDMRStart(true);
+		if (m_duplex)
+			m_modem->writeDMRStart(true);
+		else
+			m_modem->setMode(MODE_DMR);
 		m_mode = MODE_DMR;
 		m_modeTimer.start();
 		break;
@@ -629,7 +632,7 @@ void CMMDVMHost::setMode(unsigned char mode, bool logging)
 			m_dstarNetwork->enable(false);
 		if (m_dmrNetwork != NULL)
 			m_dmrNetwork->enable(false);
-		if (m_mode == MODE_DMR)
+		if (m_mode == MODE_DMR && m_duplex)
 			m_modem->writeDMRStart(false);
 		else
 			m_modem->setMode(MODE_IDLE);
@@ -657,7 +660,7 @@ void CMMDVMHost::setMode(unsigned char mode, bool logging)
 			m_dstarNetwork->enable(true);
 		if (m_dmrNetwork != NULL)
 			m_dmrNetwork->enable(true);
-		if (m_mode == MODE_DMR)
+		if (m_mode == MODE_DMR && m_duplex)
 			m_modem->writeDMRStart(false);
 		else
 			m_modem->setMode(MODE_IDLE);