diff --git a/grc/transmitter/CMakeLists.txt b/grc/transmitter/CMakeLists.txt
index 4df2abb..d66ea32 100644
--- a/grc/transmitter/CMakeLists.txt
+++ b/grc/transmitter/CMakeLists.txt
@@ -18,10 +18,10 @@
 # Boston, MA 02110-1301, USA.
 
 install(FILES
-    gsm_gmsk_mod.xml
-    gsm_txtime_bursts_tagger.xml
-    gsm_txtime_setter.xml
-    gsm_preprocess_tx_burst.xml
-    gsm_gen_test_ab.xml
+    gsm_gmsk_mod.block.yml
+    gsm_txtime_bursts_tagger.block.yml
+    gsm_txtime_setter.block.yml
+    gsm_preprocess_tx_burst.block.yml
+    gsm_gen_test_ab.block.yml
     DESTINATION share/gnuradio/grc/blocks
 )
diff --git a/grc/transmitter/gsm_gen_test_ab.block.yml b/grc/transmitter/gsm_gen_test_ab.block.yml
new file mode 100644
index 0000000..ec57b8e
--- /dev/null
+++ b/grc/transmitter/gsm_gen_test_ab.block.yml
@@ -0,0 +1,20 @@
+# auto-generated by grc.converter
+
+id: gsm_gen_test_ab
+label: Gen Test AB
+
+inputs:
+-   domain: message
+    id: bursts_in
+    optional: true
+
+outputs:
+-   domain: message
+    id: bursts_out
+    optional: true
+
+templates:
+    imports: import grgsm
+    make: grgsm.gen_test_ab()
+
+file_format: 1
diff --git a/grc/transmitter/gsm_gen_test_ab.xml b/grc/transmitter/gsm_gen_test_ab.xml
deleted file mode 100644
index 3cb8b11..0000000
--- a/grc/transmitter/gsm_gen_test_ab.xml
+++ /dev/null
@@ -1,19 +0,0 @@
-<?xml version="1.0"?>
-<block>
-  <name>Gen Test AB</name>
-  <key>gsm_gen_test_ab</key>
-  <import>import grgsm</import>
-  <make>grgsm.gen_test_ab()</make>
-
-  <sink>
-    <name>bursts_in</name>
-    <type>message</type>
-    <optional>1</optional>
-  </sink>
-
-  <source>
-    <name>bursts_out</name>
-    <type>message</type>
-    <optional>1</optional>
-  </source>
-</block>
diff --git a/grc/transmitter/gsm_gmsk_mod.block.yml b/grc/transmitter/gsm_gmsk_mod.block.yml
new file mode 100644
index 0000000..e45e303
--- /dev/null
+++ b/grc/transmitter/gsm_gmsk_mod.block.yml
@@ -0,0 +1,49 @@
+# auto-generated by grc.converter
+
+id: gsm_gmsk_mod
+label: GMSK Modulator for GSM
+
+parameters:
+-   id: BT
+    label: 3 dB Time-Bandwidth Product
+    dtype: raw
+    default: '4'
+-   id: pulse_duration
+    label: Pulse Duration
+    dtype: raw
+    default: '4'
+-   id: sps
+    label: Samples/Symbol
+    dtype: raw
+    default: '4'
+
+inputs:
+-   domain: stream
+    dtype: byte
+    vlen: 1
+    optional: true
+
+outputs:
+-   domain: stream
+    dtype: complex
+    vlen: 1
+    optional: true
+
+templates:
+    imports: from grgsm import gsm_gmsk_mod
+    make: |-
+        gsm_gmsk_mod(
+            BT=${BT},
+            pulse_duration=${pulse_duration},
+            sps=${sps},
+        )
+    callbacks:
+    - set_BT(${BT})
+    - set_pulse_duration(${pulse_duration})
+    - set_sps(${sps})
+
+documentation: |-
+    Piotr Krysik
+    GMSK Modulator for GSM
+
+file_format: 1
diff --git a/grc/transmitter/gsm_gmsk_mod.xml b/grc/transmitter/gsm_gmsk_mod.xml
deleted file mode 100644
index 4aad01b..0000000
--- a/grc/transmitter/gsm_gmsk_mod.xml
+++ /dev/null
@@ -1,47 +0,0 @@
-<block>
-  <name>GMSK Modulator for GSM</name>
-  <key>gsm_gmsk_mod</key>
-  <import>from grgsm import gsm_gmsk_mod</import>
-  <make>gsm_gmsk_mod(
-    BT=$BT,
-    pulse_duration=$pulse_duration,
-    sps=$sps,
-)</make>
-  <callback>set_BT($BT)</callback>
-  <callback>set_pulse_duration($pulse_duration)</callback>
-  <callback>set_sps($sps)</callback>
-  <param>
-    <name>3 dB Time-Bandwidth Product</name>
-    <key>BT</key>
-    <value>4</value>
-    <type>raw</type>
-  </param>
-  <param>
-    <name>Pulse Duration</name>
-    <key>pulse_duration</key>
-    <value>4</value>
-    <type>raw</type>
-  </param>
-  <param>
-    <name>Samples/Symbol</name>
-    <key>sps</key>
-    <value>4</value>
-    <type>raw</type>
-  </param>
-  <sink>
-    <name>in</name>
-    <type>byte</type>
-    <vlen>1</vlen>
-    <optional>1</optional>
-  </sink>
-  <source>
-    <name>out</name>
-    <type>complex</type>
-    <vlen>1</vlen>
-    <optional>1</optional>
-  </source>
-  <doc>Piotr Krysik
-GMSK Modulator for GSM
-  </doc>
-  <grc_source>gr-gsm/hier_blocks/transmitter/gsm_gmsk_mod.grc</grc_source>
-</block>
diff --git a/grc/transmitter/gsm_preprocess_tx_burst.block.yml b/grc/transmitter/gsm_preprocess_tx_burst.block.yml
new file mode 100644
index 0000000..09cc030
--- /dev/null
+++ b/grc/transmitter/gsm_preprocess_tx_burst.block.yml
@@ -0,0 +1,20 @@
+# auto-generated by grc.converter
+
+id: gsm_preprocess_tx_burst
+label: Preprocess Tx burst
+
+inputs:
+-   domain: message
+    id: bursts_in
+    optional: true
+
+outputs:
+-   domain: message
+    id: bursts_out
+    optional: true
+
+templates:
+    imports: import grgsm
+    make: grgsm.preprocess_tx_burst()
+
+file_format: 1
diff --git a/grc/transmitter/gsm_preprocess_tx_burst.xml b/grc/transmitter/gsm_preprocess_tx_burst.xml
deleted file mode 100644
index 70b447e..0000000
--- a/grc/transmitter/gsm_preprocess_tx_burst.xml
+++ /dev/null
@@ -1,19 +0,0 @@
-<?xml version="1.0"?>
-<block>
-  <name>Preprocess Tx burst</name>
-  <key>gsm_preprocess_tx_burst</key>
-  <import>import grgsm</import>
-  <make>grgsm.preprocess_tx_burst()</make>
-
-  <sink>
-    <name>bursts_in</name>
-    <type>message</type>
-    <optional>1</optional>
-  </sink>
-
-  <source>
-    <name>bursts_out</name>
-    <type>message</type>
-    <optional>1</optional>
-  </source>
-</block>
diff --git a/grc/transmitter/gsm_txtime_bursts_tagger.block.yml b/grc/transmitter/gsm_txtime_bursts_tagger.block.yml
new file mode 100644
index 0000000..323d084
--- /dev/null
+++ b/grc/transmitter/gsm_txtime_bursts_tagger.block.yml
@@ -0,0 +1,56 @@
+# auto-generated by grc.converter
+
+id: gsm_txtime_bursts_tagger
+label: txtime_bursts_tagger
+
+parameters:
+-   id: init_fn
+    label: init_fn
+    dtype: raw
+    default: None
+    hide: part
+-   id: init_time
+    label: init_time
+    dtype: float
+    default: '0'
+    hide: part
+-   id: time_hint
+    label: time_hint
+    dtype: float
+    default: '0'
+    hide: part
+-   id: timing_advance
+    label: timing_advance
+    dtype: float
+    default: '0'
+    hide: part
+-   id: delay_correction
+    label: delay_correction
+    dtype: float
+    default: '0'
+    hide: part
+
+inputs:
+-   domain: message
+    id: fn_time
+    optional: true
+-   domain: message
+    id: bursts
+    optional: true
+
+outputs:
+-   domain: message
+    id: bursts
+    optional: true
+
+templates:
+    imports: import grgsm
+    make: grgsm.txtime_bursts_tagger(${init_fn}, ${init_time}, ${time_hint}, ${timing_advance},
+        ${delay_correction})
+    callbacks:
+    - set_fn_time_reference(${init_fn}, ${init_time})
+    - set_time_hint(${time_hint})
+    - set_timing_advance(${timing_advance})
+    - set_delay_correction(${delay_correction})
+
+file_format: 1
diff --git a/grc/transmitter/gsm_txtime_bursts_tagger.xml b/grc/transmitter/gsm_txtime_bursts_tagger.xml
deleted file mode 100644
index 4e42886..0000000
--- a/grc/transmitter/gsm_txtime_bursts_tagger.xml
+++ /dev/null
@@ -1,69 +0,0 @@
-<?xml version="1.0"?>
-<block>
-  <name>txtime_bursts_tagger</name>
-  <key>gsm_txtime_bursts_tagger</key>
-  <import>import grgsm</import>
-  <make>grgsm.txtime_bursts_tagger($init_fn, $init_time, $time_hint, $timing_advance, $delay_correction)</make>
-  <callback>set_fn_time_reference($init_fn, $init_time)</callback>
-  <callback>set_time_hint($time_hint)</callback>
-  <callback>set_timing_advance($timing_advance)</callback>
-  <callback>set_delay_correction($delay_correction)</callback>
-
-  <param>
-    <name>init_fn</name>
-    <key>init_fn</key>
-    <value>None</value>
-    <type>raw</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>init_time</name>
-    <key>init_time</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>time_hint</name>
-    <key>time_hint</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>timing_advance</name>
-    <key>timing_advance</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>delay_correction</name>
-    <key>delay_correction</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <sink>
-    <name>fn_time</name>
-    <type>message</type>
-    <optional>1</optional>
-  </sink>
-
-  <sink>
-    <name>bursts</name>
-    <type>message</type>
-    <optional>1</optional>
-  </sink>
-
-  <source>
-    <name>bursts</name>
-    <type>message</type>
-    <optional>1</optional>
-  </source>
-</block>
diff --git a/grc/transmitter/gsm_txtime_setter.block.yml b/grc/transmitter/gsm_txtime_setter.block.yml
new file mode 100644
index 0000000..76a3f37
--- /dev/null
+++ b/grc/transmitter/gsm_txtime_setter.block.yml
@@ -0,0 +1,67 @@
+# auto-generated by grc.converter
+
+id: gsm_txtime_setter
+label: txtime_setter
+
+parameters:
+-   id: init_fn
+    label: init_fn
+    dtype: raw
+    default: None
+    hide: part
+-   id: init_time_secs
+    label: init_time_secs
+    dtype: int
+    default: '0'
+    hide: part
+-   id: init_time_fracs
+    label: init_time_fracs
+    dtype: float
+    default: '0'
+    hide: part
+-   id: time_hint_secs
+    label: time_hint_secs
+    dtype: int
+    default: '0'
+    hide: part
+-   id: time_hint_fracs
+    label: time_hint_fracs
+    dtype: float
+    default: '0'
+    hide: part
+-   id: timing_advance
+    label: timing_advance
+    dtype: float
+    default: '0'
+    hide: part
+-   id: delay_correction
+    label: delay_correction
+    dtype: float
+    default: '0'
+    hide: part
+
+inputs:
+-   domain: message
+    id: fn_time
+    optional: true
+-   domain: message
+    id: bursts_in
+    optional: true
+
+outputs:
+-   domain: message
+    id: bursts_out
+    optional: true
+
+templates:
+    imports: import grgsm
+    make: grgsm.txtime_setter(${init_fn} if (${init_fn} is not None) else 0xffffffff,
+        ${init_time_secs}, ${init_time_fracs}, ${time_hint_secs}, ${time_hint_fracs},
+        ${timing_advance}, ${delay_correction})
+    callbacks:
+    - set_fn_time_reference(${init_fn}, ${init_time_secs}, ${init_time_fracs})
+    - set_time_hint(${time_hint_secs}, ${time_hint_secs})
+    - set_timing_advance(${timing_advance})
+    - set_delay_correction(${delay_correction})
+
+file_format: 1
diff --git a/grc/transmitter/gsm_txtime_setter.xml b/grc/transmitter/gsm_txtime_setter.xml
deleted file mode 100644
index 648f4d9..0000000
--- a/grc/transmitter/gsm_txtime_setter.xml
+++ /dev/null
@@ -1,84 +0,0 @@
-<?xml version="1.0"?>
-<block>
-  <name>txtime_setter</name>
-  <key>gsm_txtime_setter</key>
-  <import>import grgsm</import>
-  <make>grgsm.txtime_setter($init_fn if ($init_fn is not None) else 0xffffffff, $init_time_secs, $init_time_fracs, $time_hint_secs, $time_hint_fracs, $timing_advance, $delay_correction)</make>
-  
-  <callback>set_fn_time_reference($init_fn, $init_time_secs, $init_time_fracs)</callback>
-  <callback>set_time_hint($time_hint_secs, $time_hint_secs)</callback>
-  <callback>set_timing_advance($timing_advance)</callback>
-  <callback>set_delay_correction($delay_correction)</callback>
-
-  <param>
-    <name>init_fn</name>
-    <key>init_fn</key>
-    <value>None</value>
-    <type>raw</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>init_time_secs</name>
-    <key>init_time_secs</key>
-    <value>0</value>
-    <type>int</type>
-    <hide>part</hide>
-  </param>
-  <param>
-    <name>init_time_fracs</name>
-    <key>init_time_fracs</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>time_hint_secs</name>
-    <key>time_hint_secs</key>
-    <value>0</value>
-    <type>int</type>
-    <hide>part</hide>
-  </param>
-  <param>
-    <name>time_hint_fracs</name>
-    <key>time_hint_fracs</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>timing_advance</name>
-    <key>timing_advance</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <param>
-    <name>delay_correction</name>
-    <key>delay_correction</key>
-    <value>0</value>
-    <type>float</type>
-    <hide>part</hide>
-  </param>
-
-  <sink>
-    <name>fn_time</name>
-    <type>message</type>
-    <optional>1</optional>
-  </sink>
-
-  <sink>
-    <name>bursts_in</name>
-    <type>message</type>
-    <optional>1</optional>
-  </sink>
-
-  <source>
-    <name>bursts_out</name>
-    <type>message</type>
-    <optional>1</optional>
-  </source>
-</block>