diff --git a/grc/rds_encoder.block.yml b/grc/rds_encoder.block.yml
index b7fb61c..8ac5e55 100644
--- a/grc/rds_encoder.block.yml
+++ b/grc/rds_encoder.block.yml
@@ -1,109 +1,114 @@
-# auto-generated by grc.converter
+# Auto-generated by grc.converter
 
 id: rds_encoder
 label: RDS Encoder
 category: '[RDS]'
 
 parameters:
--   id: pty_locale
-    label: PTY Locale
-    dtype: int
-    default: '0'
-    options: ['0', '1']
+  - id: af1
+    label: AF1
+    dtype: float
+    default: None
+    optional: true
     option_labels: [Europe, North America]
--   id: pty
+
+  - id: pty
     label: PTY
     dtype: int
     default: '14'
     options: ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12',
-        '13', '14', '15', '16', '17', '18', '19', '20', '21', '22', '23', '24', '25',
-        '26', '27', '28', '29', '30', '31']
-    option_labels: [Undefined, News, Current Affairs / Information, Information /
-            Sports, Sport / Talk, Education / Rock, Drama / Classic Rock, Culture
-            / Adult Hits, Science / Soft Rock, Varied / Top 40, Pop Music / Country,
-        Rock Music / Oldies, Easy Listening / Soft, Light Classical / Nostalgia, Serious
-            Classical / Jazz, Other Music / Classical, Weather / Rhythm & Blues, Finance
-            / Soft Rhythm & Blues, "Children\u2019s Programmes / Language", Social
-            Affairs / Religious Music, Religion / Religious Talk, Phone-In / Personality,
-        Travel / Public, Leisure / College, Jazz Music / Spanish Talk, Country Music
-            / Spanish Music, National Music / Hip Hop, Oldies Music / Unassigned,
-        Folk Music / Unassigned, Documentary / Weather, Alarm Test / Emergency Test,
-        Alarm / Emergency]
--   id: ms
+              '13', '14', '15', '16', '17', '18', '19', '20', '21', '22', '23', '24', '25',
+              '26', '27', '28', '29', '30', '31']
+    option_labels: [Undefined, News, Current Affairs, Information, Sports, Talk, Education,
+                    Rock, Drama, Classic Rock, Culture, Adult Hits, Science, Soft Rock,
+                    Pop Music, Country, Rock Music, Oldies, Easy Listening, Soft,
+                    Light Classical, Nostalgia, Serious Classical, Jazz, Other Music,
+                    Classical, Weather, Rhythm & Blues, Finance, Soft Rhythm & Blues,
+                    Children's Programmes, Language, Social Affairs, Religious Music,
+                    Religion, Religious Talk, Phone-In, Personality, Travel, Public,
+                    Leisure, College, Jazz Music, Spanish Talk, Country Music, Spanish Music,
+                    National Music, Hip Hop, Oldies Music, Folk Music, Documentary,
+                    Weather, Alarm Test, Emergency Test, Alarm, Emergency]
+
+  - id: ms
     label: MS
     dtype: bool
     default: 'True'
     options: ['True', 'False']
     option_labels: [Music, Speech]
--   id: ps
+
+  - id: ps
     label: PS
     dtype: string
     default: WDR 3
--   id: af1
-    label: AF1
-    dtype: float
-    default: 89.8e6
--   id: tp
+
+  - id: tp
     label: TP
     dtype: bool
     default: 'True'
     options: ['True', 'False']
--   id: ta
+
+  - id: ta
     label: TA
     dtype: bool
     default: 'False'
     options: ['True', 'False']
--   id: pi_country_code
+
+  - id: pi_country_code
     label: PI Country Code
     dtype: int
     default: '13'
-    options: ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13',
-        '15']
+    options: ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '15']
     option_labels: [Other, DE, DZ, AD, IL, IT, BE, RU, PS, AL, AT, HU, MT, DE, EG]
--   id: pi_coverage_area
+
+  - id: pi_coverage_area
     label: PI Coverage Area
     dtype: int
     default: '3'
     options: ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12',
-        '13', '14', '15']
-    option_labels: [Local, International, National, Supra-regional, Regional 1, Regional
-            2, Regional 3, Regional 4, Regional 5, Regional 6, Regional 7, Regional
-            8, Regional 9, Regional 10, Regional 11, Regional 12]
+              '13', '14', '15']
+    option_labels: [Local, International, National, Supra-regional, Regional 1, Regional 2,
+                    Regional 3, Regional 4, Regional 5, Regional 6, Regional 7, Regional 8,
+                    Regional 9, Regional 10, Regional 11, Regional 12]
     hide: ${ ('all' if str(pi_country_code) == '0' else 'none') }
--   id: pi_reference_number
+
+  - id: pi_reference_number
     label: ${ ('PI Code' if str(pi_country_code) == '0' else 'PI Program Reference Number') }
     dtype: int
     default: '147'
--   id: radiotext
+
+  - id: radiotext
     label: Radiotext
     dtype: string
     default: GNU Radio <3
 
 inputs:
--   domain: message
-    id: rds in
+  - domain: message
+    id: rds_in
     optional: true
 
 outputs:
--   domain: stream
+  - domain: stream
     dtype: byte
 
 templates:
-    imports: import rds
-    make: "rds.encoder(${pty_locale}, ${pty}, ${ms}, ${ps}, ${af1},\n\t\t\t${tp},\
-        \ ${ta}, ${pi_country_code}, ${pi_coverage_area},\n\t\t\t${pi_reference_number},\
-        \ ${radiotext})\n\t"
-    callbacks:
-    - set_ps(${ps})
-
-documentation: |-
-    PTY: Program Type (depending on PTY locale)
-    MS: Speech/Music
-    PS: Program Service Name
-    AF: Alternate Frequency
-    TP: Traffic Program
-    TA: Traffic Announcment
-    PI: Program Identification (country code, coverage area, reference number)
-    Radiotext: Radiotext (obviously)
+  make: "rds.encoder(${pty_locale}, ${pty}, ${ms}, ${ps}"
+% if af1 is not None:
+make += ", ${af1}"
+% endif
+make += ", ${tp}, ${ta}, ${pi_country_code}, ${pi_coverage_area}, ${pi_reference_number}, ${radiotext})"
+
+callbacks:
+  - set_ps(${ps})
+
+documentation: |
+  PTY: Program Type (depending on PTY locale)
+  MS: Speech/Music
+  PS: Program Service Name
+  AF: Alternate Frequency
+  TP: Traffic Program
+  TA: Traffic Announcement
+  PI: Program Identification (country code, coverage area, reference number)
+  Radiotext: Radiotext (obviously)
 
 file_format: 1