diff --git a/plugins/channeltx/modm17/CMakeLists.txt b/plugins/channeltx/modm17/CMakeLists.txt
index 82d0a789a..97e2ad3ff 100644
--- a/plugins/channeltx/modm17/CMakeLists.txt
+++ b/plugins/channeltx/modm17/CMakeLists.txt
@@ -5,6 +5,7 @@ set(modm17_SOURCES
     m17modbaseband.cpp
     m17modsource.cpp
     m17modprocessor.cpp
+    m17modfifo.cpp
 	m17modplugin.cpp
     m17modsettings.cpp
     m17modwebapiadapter.cpp
@@ -15,6 +16,7 @@ set(modm17_HEADERS
     m17modbaseband.h
     m17modsource.h
     m17modprocessor.h
+    m17modfifo.h
 	m17modplugin.h
     m17modsettings.h
     m17modwebapiadapter.h
diff --git a/plugins/channeltx/modm17/m17modfifo.cpp b/plugins/channeltx/modm17/m17modfifo.cpp
new file mode 100644
index 000000000..128baadbe
--- /dev/null
+++ b/plugins/channeltx/modm17/m17modfifo.cpp
@@ -0,0 +1,114 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2022 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "m17modfifo.h"
+
+M17ModFIFO::M17ModFIFO() :
+	m_fifo(nullptr)
+{
+	m_size = 0;
+	m_writeIndex = 0;
+	m_readIndex = 0;
+}
+
+M17ModFIFO::M17ModFIFO(uint32_t numSamples) :
+	m_fifo(nullptr)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	create(numSamples);
+}
+
+M17ModFIFO::~M17ModFIFO()
+{
+	QMutexLocker mutexLocker(&m_mutex);
+
+	if (m_fifo)
+	{
+		delete[] m_fifo;
+		m_fifo = nullptr;
+	}
+
+	m_size = 0;
+}
+
+void M17ModFIFO::setSize(uint32_t numSamples)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	create(numSamples);
+}
+
+void M17ModFIFO::create(uint32_t numSamples)
+{
+	if (m_fifo)
+	{
+		delete[] m_fifo;
+		m_fifo = nullptr;
+	}
+
+	m_writeIndex = 0;
+	m_readIndex = 0;
+
+	m_fifo = new int16_t[numSamples];
+	m_size = numSamples;
+}
+
+uint32_t M17ModFIFO::write(const int16_t* data, uint32_t numSamples)
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+    if (m_readIndex > m_writeIndex)
+    {
+        int rem = m_readIndex - m_writeIndex;
+        int written = std::min(rem, (int) numSamples);
+        std::copy(data, data + written, &m_fifo[m_writeIndex]);
+        m_writeIndex += written;
+        return written;
+    }
+
+    int remSize = m_size - m_writeIndex;
+    int written = std::min(remSize, (int) numSamples);
+    std::copy(data, data + written, &m_fifo[m_writeIndex]);
+    m_writeIndex += written;
+    m_writeIndex = m_writeIndex == (int) m_size ? 0 : m_writeIndex;
+
+    if (written == (int) numSamples) {
+        return written;
+    }
+
+    // wrap
+    int remWrite = (int) numSamples - written;
+    int remWritten = std::min(remWrite, m_readIndex);
+    std::copy(data + written, data + written + remWritten, m_fifo);
+    m_writeIndex = remWritten;
+    return written + remWritten;
+}
+
+uint32_t M17ModFIFO::readOne(int16_t* data)
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+    if (m_readIndex == m_writeIndex)
+    {
+        *data = 0;
+        return 0;
+    }
+
+    *data = m_fifo[m_readIndex++];
+    m_readIndex = m_readIndex == (int) m_size ? 0 : m_readIndex;
+    return 1;
+}
+
diff --git a/plugins/channeltx/modm17/m17modfifo.h b/plugins/channeltx/modm17/m17modfifo.h
new file mode 100644
index 000000000..84e95fe21
--- /dev/null
+++ b/plugins/channeltx/modm17/m17modfifo.h
@@ -0,0 +1,47 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2022 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef PLUGINS_CHANNELTX_MODM17_M17MODFIFO_H_
+#define PLUGINS_CHANNELTX_MODM17_M17MODFIFO_H_
+
+#include <QObject>
+#include <QMutex>
+
+class M17ModFIFO: public QObject
+{
+	Q_OBJECT
+public:
+	M17ModFIFO();
+	M17ModFIFO(uint32_t numSamples);
+	~M17ModFIFO();
+
+	void setSize(uint32_t numSamples);
+	uint32_t write(const int16_t* data, uint32_t numSamples);
+    uint32_t readOne(int16_t* data);
+
+private:
+	QMutex m_mutex;
+	int16_t* m_fifo;
+    uint32_t m_size;
+    int m_writeIndex;
+    int m_readIndex;
+
+    void create(uint32_t numSamples);
+};
+
+
+#endif // PLUGINS_CHANNELTX_MODM17_M17MODFIFO_H_
diff --git a/plugins/channeltx/modm17/m17modprocessor.cpp b/plugins/channeltx/modm17/m17modprocessor.cpp
index 2ef296589..070ce03e7 100644
--- a/plugins/channeltx/modm17/m17modprocessor.cpp
+++ b/plugins/channeltx/modm17/m17modprocessor.cpp
@@ -24,7 +24,7 @@ MESSAGE_CLASS_DEFINITION(M17ModProcessor::MsgSendSMS, Message)
 M17ModProcessor::M17ModProcessor() :
     m_m17Modulator("MYCALL", "")
 {
-    m_basebandFifo.setSampleSize(sizeof(int16_t), 96000);
+    m_basebandFifo.setSize(96000);
     connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
 }
 
@@ -114,7 +114,7 @@ void M17ModProcessor::send_preamble()
     preamble_bytes.fill(0x77);
     std::array<int8_t, 192> preamble_symbols = mobilinkd::M17Modulator::bytes_to_symbols(preamble_bytes);
     std::array<int16_t, 1920> preamble_baseband = m_m17Modulator.symbols_to_baseband(preamble_symbols);
-    m_basebandFifo.write((const quint8*) preamble_baseband.data(), 1920);
+    m_basebandFifo.write(preamble_baseband.data(), 1920);
 }
 
 void M17ModProcessor::send_eot()
@@ -128,7 +128,7 @@ void M17ModProcessor::send_eot()
 
     std::array<int8_t, 192> eot_symbols = mobilinkd::M17Modulator::bytes_to_symbols(eot_bytes);
     std::array<int16_t, 1920> eot_baseband = m_m17Modulator.symbols_to_baseband(eot_symbols);
-    m_basebandFifo.write((const quint8*) eot_baseband.data(), 1920);
+    m_basebandFifo.write(eot_baseband.data(), 1920);
 }
 
 void M17ModProcessor::output_baseband(std::array<uint8_t, 2> sync_word, const std::array<int8_t, 368>& frame)
@@ -140,5 +140,5 @@ void M17ModProcessor::output_baseband(std::array<uint8_t, 2> sync_word, const st
     auto fit = std::copy(sw.begin(), sw.end(), temp.begin()); // start with sync word dibits
     std::copy(symbols.begin(), symbols.end(), fit); // then the frame dibits
     std::array<int16_t, 1920> baseband = m_m17Modulator.symbols_to_baseband(temp); // 1920 48 kS/s int16_t samples
-    m_basebandFifo.write((const quint8*) baseband.data(), 1920);
+    m_basebandFifo.write(baseband.data(), 1920);
 }
diff --git a/plugins/channeltx/modm17/m17modprocessor.h b/plugins/channeltx/modm17/m17modprocessor.h
index 5492b3e28..72331a13f 100644
--- a/plugins/channeltx/modm17/m17modprocessor.h
+++ b/plugins/channeltx/modm17/m17modprocessor.h
@@ -24,7 +24,7 @@
 #include "m17/M17Modulator.h"
 #include "util/message.h"
 #include "util/messagequeue.h"
-#include "audio/audiofifo.h"
+#include "m17modfifo.h"
 
 class M17ModProcessor : public QObject
 {
@@ -59,11 +59,11 @@ public:
     ~M17ModProcessor();
 
     MessageQueue *getInputMessageQueue() { return &m_inputMessageQueue; }
-    AudioFifo *getBasebandFifo() { return &m_basebandFifo; }
+    M17ModFIFO *getBasebandFifo() { return &m_basebandFifo; }
 
 private:
     MessageQueue m_inputMessageQueue;
-    AudioFifo m_basebandFifo; //!< Samples are 16 bit integer baseband 48 kS/s samples
+    M17ModFIFO m_basebandFifo; //!< Samples are 16 bit integer baseband 48 kS/s samples
     mobilinkd::M17Modulator m_m17Modulator;
 
     bool handleMessage(const Message& cmd);
diff --git a/plugins/channeltx/modm17/m17modsource.cpp b/plugins/channeltx/modm17/m17modsource.cpp
index 2235d4ee6..d87e6ed5a 100644
--- a/plugins/channeltx/modm17/m17modsource.cpp
+++ b/plugins/channeltx/modm17/m17modsource.cpp
@@ -272,9 +272,8 @@ void M17ModSource::pullAF(Real& sample, bool& carrier)
 
 void M17ModSource::pullM17(Real& sample, bool& carrier)
 {
-    quint8 bbSampleBytes[2];
-    carrier = m_processor->getBasebandFifo()->readOne(bbSampleBytes);
-    int16_t basbandSample = bbSampleBytes[0] | (bbSampleBytes[1]<<8);
+    int16_t basbandSample;
+    carrier = m_processor->getBasebandFifo()->readOne(&basbandSample) != 0;
 
     if (carrier)
     {