diff --git a/add_gr3.9.py b/add_gr3.9.py
new file mode 100644
index 0000000..99e5297
--- /dev/null
+++ b/add_gr3.9.py
@@ -0,0 +1,161 @@
+#! /usr/bin/python3
+
+import sys
+import os
+import glob
+import shutil
+from gnuradio.modtool.core.newmod import ModToolNewModule
+from gnuradio.modtool.core.add import ModToolAdd
+from gnuradio.modtool.core.bind import ModToolGenBindings
+
+TLD = 'op25'
+
+MODS={
+	'op25': 'decoder_bf decoder_ff fsk4_demod_ff fsk4_slicer_fb pcap_source_b'.split(),
+	'op25_repeater': 'ambe_encoder_sb dmr_bs_tx_bb dstar_tx_sb frame_assembler fsk4_slicer_fb gardner_costas_cc nxdn_tx_sb p25_frame_assembler vocoder ysf_tx_sb'.split()
+}
+
+SKIP_CC = 'd2460.cc qa_op25.cc test_op25.cc qa_op25_repeater.cc test_op25_repeater.cc'.split()
+
+SRC_DIR = sys.argv[1]
+DEST_DIR = sys.argv[2]
+
+if  '..' in SRC_DIR or not SRC_DIR.startswith('/'):
+	sys.stderr.write('error, %s must be an absolute path\n' % SRC_DIR)
+	sys.exit(1)
+
+if not os.access(SRC_DIR, os.R_OK):
+	sys.stderr.write('error, unable to access %s\n' % SRC_DIR)
+	sys.exit(1)
+
+if not os.path.isdir(SRC_DIR + '/op25/gr-op25_repeater'):
+	sys.stderr.write('error, op25 package not found in %s\n' % SRC_DIR)
+	sys.exit(3)
+
+if os.access(DEST_DIR, os.F_OK) or os.path.isdir(DEST_DIR):
+	sys.stderr.write('error, destination path %s must not exist\n' % DEST_DIR)
+	sys.exit(4)
+
+os.mkdir(DEST_DIR)
+op25_dir = DEST_DIR + '/op25'
+os.mkdir(op25_dir)
+os.chdir(op25_dir)
+
+def edit_cmake(filename, mod, srcfiles):
+	lines = open(filename).read().rstrip().split('\n')
+	srcdefs = []
+	state = 0
+	end_mark = 0
+	tll = 0	# target_link_library
+	srcfiles = [s.split('/')[-1] for s in srcfiles if s.endswith('.cc') or s.endswith('.c') or s.endswith('.cpp')]
+	for i in range(len(lines)):
+		if lines[i].startswith('list(APPEND op25_') and '_sources' in lines[i]:
+			state = 1
+			continue
+		elif ')' in lines[i] and state:
+			state = 0
+			end_mark = i
+			continue
+		elif lines[i].startswith('target_link_libraries(gnuradio-op25'):
+			assert lines[i].endswith(')')
+			tll = i
+			continue
+		if state:
+			srcdefs.append(lines[i].strip())
+	srcfiles = ["    %s" % s for s in srcfiles if s not in srcdefs and s not in SKIP_CC]
+	tlls = {
+		'op25': 'target_link_libraries(gnuradio-op25 gnuradio::gnuradio-runtime Boost::system Boost::program_options Boost::filesystem Boost::thread itpp pcap)',
+		'op25_repeater': 'target_link_libraries(gnuradio-op25_repeater PUBLIC gnuradio::gnuradio-runtime gnuradio::gnuradio-filter PRIVATE imbe_vocoder)'
+	}
+	assert tll	# fail if target_link_libraries line not found
+	lines[tll] = tlls[mod]
+	if mod == 'op25_repeater':
+		lines = lines[:tll] + ['\n' + 'add_subdirectory(imbe_vocoder)\n'] + lines[tll:]
+
+	new_lines = lines[:end_mark] + srcfiles + lines[end_mark:]
+	s = '\n'.join(new_lines)
+	s += '\n'
+	with open(filename, 'w') as fp:
+		fp.write(s)
+
+def get_args_from_h(mod):
+	lines = open(mod).read().rstrip().split('\n')
+
+	lines = [line for line in lines if 'make' in line]
+
+	answer = []
+	for s in lines:
+		s = s.rstrip()
+		if s[-1] != ';':
+			continue
+		s = s[:-1]
+		s = s.rstrip()
+		if s[-1] != ')':
+			continue
+		s = s[:-1]
+		lp = s.find('(')
+		if lp > 0:
+			s =s[lp+1:]
+		else:
+			continue
+		for arg in s.split(','):
+			eq = arg.find('=')
+			if eq > 0:
+				arg = arg[:eq]
+			answer.append(arg)
+		return ','.join(answer)
+	return ''
+
+for mod in sorted(MODS.keys()):
+	m = ModToolNewModule(module_name=mod, srcdir=None)
+	m.run()
+	print('gr_modtool newmod %s getcwd now %s' % (mod, os.getcwd()))
+	pfx = '%s/op25/gr-%s' % (SRC_DIR, mod)
+	lib = '%s/lib' % pfx
+	incl = '%s/include/%s' % (pfx, mod)
+	d_pfx = '%s/op25/gr-%s' % (DEST_DIR, mod)
+	d_lib = '%s/lib' % d_pfx
+	d_incl = '%s/include/%s' % (d_pfx, mod)
+	for block in MODS[mod]:
+		include = '%s/%s.h' % (incl, block)
+		args = get_args_from_h(include)
+		t = 'sync' if block == 'fsk4_slicer_fb' else 'general'
+		print ('add %s %s type %s directory %s args %s' % (mod, block, t, os.getcwd(), args))
+		m = ModToolAdd(blockname=block,block_type=t,lang='cpp',copyright='Steve Glass, OP25 Group', argument_list=args)
+		m.run()
+
+	srcfiles = []
+	srcfiles += glob.glob('%s/lib/*.cc' % pfx)
+	srcfiles += glob.glob('%s/lib/*.cpp' % pfx)
+	srcfiles += glob.glob('%s/lib/*.c' % pfx)
+	srcfiles += glob.glob('%s/lib/*.h' % pfx)
+	hfiles = []
+	hfiles += glob.glob('%s/include/%s/*.h' % (pfx, mod))
+
+	assert os.path.isdir(d_lib)
+	assert os.path.isdir(d_incl)
+
+	for f in srcfiles:
+		shutil.copy(f, d_lib)
+	for f in hfiles:
+		shutil.copy(f, d_incl)
+
+	if mod == 'op25_repeater':
+		for d in 'imbe_vocoder ezpwd'.split():
+			os.mkdir('%s/%s' % (d_lib, d))
+			imbefiles = []
+			imbefiles += glob.glob('%s/%s/*' % (lib, d))
+			dest = '%s/%s' % (d_lib, d)
+			for f in imbefiles:
+				shutil.copy(f, dest)
+
+	edit_cmake('%s/CMakeLists.txt' % d_lib, mod, srcfiles)
+
+	os.system('/bin/bash %s/do_sed.sh' % (SRC_DIR))
+
+	for block in MODS[mod]:
+		print ('bind %s %s' % (mod, block))
+		m = ModToolGenBindings(block, addl_includes='', define_symbols='')
+		m.run()
+
+	os.chdir(op25_dir)
diff --git a/do_sed.sh b/do_sed.sh
new file mode 100644
index 0000000..46e0878
--- /dev/null
+++ b/do_sed.sh
@@ -0,0 +1,12 @@
+#! /bin/sh
+
+srcs=`find lib include -name '*.c' -o -name '*.h' -o -name '*.cc'`
+files=`grep -l 'boost.*shared_ptr' $srcs`
+
+dir=`pwd`
+
+for f in $files; do
+	echo editing file $f in $dir
+	sed -i 's%boost/shared_ptr.hpp%memory%' $f
+	sed -i 's%boost::shared_ptr%std::shared_ptr%' $f
+done
diff --git a/install-gr3.9.sh b/install-gr3.9.sh
new file mode 100644
index 0000000..1122c77
--- /dev/null
+++ b/install-gr3.9.sh
@@ -0,0 +1,71 @@
+#! /bin/bash
+
+# op25 install script for debian based systems
+# including ubuntu 14/16 and raspbian
+#
+# *** this script for gnuradio 3.9 and 3.10 ***
+
+TREE_DIR="$PWD/src"	# directory in which our gr3.9 tree will be built
+
+if [ ! -d op25/gr-op25 ]; then
+	echo ====== error, op25 top level directories not found
+	echo ====== you must change to the op25 top level directory
+	echo ====== before running this script
+	exit
+fi
+
+sudo apt-get update
+sudo apt-get build-dep gnuradio
+sudo apt-get install gnuradio gnuradio-dev gr-osmosdr librtlsdr-dev libuhd-dev  libhackrf-dev libitpp-dev libpcap-dev cmake git swig build-essential pkg-config doxygen python3-numpy python3-waitress python3-requests python3-pip pybind11-dev
+
+pip3 install --user pygccxml
+
+# setup and populate gr3.9 src tree
+echo
+echo " = = = = = = = generating source tree for gr3.9, this could take a while = = = = = = ="
+echo
+python3 add_gr3.9.py $PWD $TREE_DIR
+if [ ! -d $TREE_DIR ]; then
+	echo ==== Error, directory $TREE_DIR creation failed, exiting
+	exit 1
+fi
+
+f="$TREE_DIR/op25/gr-op25_repeater/CMakeLists.txt"
+echo "editing cmake file $f"
+if [ ! -f $f ]; then
+	echo ==== Error, file $f not found 
+fi
+sed -i 's/^find_package(Gnuradio .*REQUIRED)/find_package(Gnuradio "3.9" REQUIRED COMPONENTS blocks fft filter)/' $f
+
+cd $TREE_DIR
+
+mkdir build
+cd build
+cmake ../op25/gr-op25
+make
+sudo make install
+sudo ldconfig
+cd ../
+
+mkdir build_repeater
+cd build_repeater
+cmake ../op25/gr-op25_repeater
+make
+sudo make install
+sudo ldconfig
+cd ../
+
+echo ====== 
+echo ====== NOTICE 
+echo ====== 
+echo ====== The gnuplot package is not installed by default here,
+echo ====== as its installation requires numerous prerequisite packages
+echo ====== that you may not want to install.
+echo ====== 
+echo ====== In order to do plotting in rx.py using the \-P option
+echo ====== you must install gnuplot, e.g., manually as follows:
+echo ====== 
+echo ====== sudo apt-get install gnuplot-x11
+echo ====== 
+
+