diff --git a/src/algorithms/signal_source/adapters/CMakeLists.txt b/src/algorithms/signal_source/adapters/CMakeLists.txt
index ab24d5fc1..717b8ac00 100644
--- a/src/algorithms/signal_source/adapters/CMakeLists.txt
+++ b/src/algorithms/signal_source/adapters/CMakeLists.txt
@@ -6,48 +6,41 @@
 
 
 # Optional drivers
-set(OPT_DRIVER_SOURCES "")
-set(OPT_DRIVER_HEADERS "")
 
 if(ENABLE_RAW_UDP AND PCAP_FOUND)
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} custom_udp_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} custom_udp_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES custom_udp_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS custom_udp_signal_source.h)
 endif()
 
-
 if(ENABLE_PLUTOSDR)
     ##############################################
     # ADALM-PLUTO (Analog Devices Inc.)
     ##############################################
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} plutosdr_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} plutosdr_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES plutosdr_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS plutosdr_signal_source.h)
 endif()
 
-
 if(ENABLE_FMCOMMS2)
     ###############################################
     # FMCOMMS2 based SDR Hardware
     ###############################################
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} fmcomms2_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} fmcomms2_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES fmcomms2_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS fmcomms2_signal_source.h)
 endif()
 
-
 if(ENABLE_AD9361)
     ###############################################
     # AD9361 DIRECT TO FPGA Hardware
     ###############################################
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} ad9361_fpga_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} ad9361_fpga_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES ad9361_fpga_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS ad9361_fpga_signal_source.h)
 endif()
 
-
 if(ENABLE_FLEXIBAND AND TELEORBIT_FOUND)
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} flexiband_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} flexiband_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES flexiband_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS flexiband_signal_source.h)
 endif()
 
-
 if(ENABLE_ARRAY)
     ##############################################
     # DBFCTTC GNSS EXPERIMENTAL ARRAY PROTOTYPE
@@ -56,32 +49,30 @@ if(ENABLE_ARRAY)
         message(" gr-dbfcttc not found, install it from https://github.com/gnss-sdr/gr-dbfcttc")
         message(FATAL_ERROR "gr-dbfcttc required for building gnss-sdr with this option enabled")
     endif()
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} raw_array_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} raw_array_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES raw_array_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS raw_array_signal_source.h)
 endif()
 
-
 if(ENABLE_OSMOSDR)
     ################################################################################
     # OsmoSDR - https://osmocom.org/projects/gr-osmosdr/
     ################################################################################
     if(GROSMOSDR_FOUND)
-        set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} osmosdr_signal_source.cc)
-        set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} osmosdr_signal_source.h)
+        list(APPEND OPT_DRIVER_SOURCES osmosdr_signal_source.cc)
+        list(APPEND OPT_DRIVER_HEADERS osmosdr_signal_source.h)
     endif()
 endif()
 
 if(ENABLE_LIMESDR)
     if(GRLIMESDR_FOUND)
-        set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} limesdr_signal_source.cc)
-        set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} limesdr_signal_source.h)
+        list(APPEND OPT_DRIVER_SOURCES limesdr_signal_source.cc)
+        list(APPEND OPT_DRIVER_HEADERS limesdr_signal_source.h)
     endif()
 endif()
 
-
 if(ENABLE_UHD)
-    set(OPT_DRIVER_SOURCES ${OPT_DRIVER_SOURCES} uhd_signal_source.cc)
-    set(OPT_DRIVER_HEADERS ${OPT_DRIVER_HEADERS} uhd_signal_source.h)
+    list(APPEND OPT_DRIVER_SOURCES uhd_signal_source.cc)
+    list(APPEND OPT_DRIVER_HEADERS uhd_signal_source.h)
 endif()
 
 if(ENABLE_ZMQ)
@@ -89,7 +80,6 @@ if(ENABLE_ZMQ)
     list(APPEND OPT_DRIVER_HEADERS zmq_signal_source.h)
 endif()
 
-
 set(SIGNAL_SOURCE_ADAPTER_SOURCES
     signal_source_base.cc
     file_source_base.cc
@@ -218,7 +208,6 @@ if(ENABLE_LIMESDR AND GRLIMESDR_FOUND)
     )
 endif()
 
-
 if(ENABLE_AD9361 AND LIBIIO_FOUND)
     target_link_libraries(signal_source_adapters
         PRIVATE
@@ -302,8 +291,6 @@ target_compile_definitions(signal_source_adapters
     PRIVATE -DGNSSSDR_INSTALL_DIR="${CMAKE_INSTALL_PREFIX}"
 )
 
-
-
 set_property(TARGET signal_source_adapters
     APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
diff --git a/src/algorithms/signal_source/gnuradio_blocks/labsat23_source.cc b/src/algorithms/signal_source/gnuradio_blocks/labsat23_source.cc
index ea92274f3..dafa79e37 100644
--- a/src/algorithms/signal_source/gnuradio_blocks/labsat23_source.cc
+++ b/src/algorithms/signal_source/gnuradio_blocks/labsat23_source.cc
@@ -32,6 +32,10 @@
 #include <sstream>
 #include <utility>
 
+#if HAS_BOOST_ENDIAN
+#include <boost/endian/conversion.hpp>
+#endif
+
 
 labsat23_source_sptr labsat23_make_source_sptr(const char *signal_file_basename, const std::vector<int> &channel_selector, Concurrent_Queue<pmt::pmt_t> *queue, bool digital_io_enabled)
 {
@@ -737,7 +741,8 @@ void labsat23_source::decode_ls3w_register(uint64_t input, std::vector<gr_comple
 {
     std::bitset<64> bs(input);
 
-    // Reverse, since register are written to file as 64-bit little endian words
+    // Earlier samples are written in the MSBs of the register. Bit-reverse the register
+    // for easier indexing. Note this bit-reverses individual samples as well for quant > 1 bit
     for (std::size_t i = 0; i < 32; ++i)
         {
             bool t = bs[i];
@@ -1074,14 +1079,20 @@ int labsat23_source::general_work(int noutput_items,
                     std::size_t output_pointer = 0;
                     for (int i = 0; i < registers_to_read; i++)
                         {
+                            uint64_t read_register = 0ULL;
+                            // Labsat3W writes its 64-bit shift register to files in little endian. Read and convert to host endianness.
+#if HAS_BOOST_ENDIAN
+                            binary_input_file.read(reinterpret_cast<char *>(&read_register), sizeof(read_register));
+                            boost::endian::little_to_native_inplace(read_register);
+#else
                             std::array<char, 8> memory_block{};
                             binary_input_file.read(memory_block.data(), 8);
-                            uint64_t read_register = 0ULL;
                             for (int k = 7; k >= 0; --k)
                                 {
                                     read_register <<= 8;
-                                    read_register |= uint64_t(memory_block[k]);
+                                    read_register |= uint64_t(memory_block[k]);  // This is buggy if the MSB of the char is set.
                                 }
+#endif
 
                             if (binary_input_file.gcount() == 8)
                                 {