diff --git a/youtube_dl/extractor/orf.py b/youtube_dl/extractor/orf.py
index 71da432c9..700ce448c 100644
--- a/youtube_dl/extractor/orf.py
+++ b/youtube_dl/extractor/orf.py
@@ -167,7 +167,7 @@ class ORFRadioIE(InfoExtractor):
 
         data = self._download_json(
             'http://audioapi.orf.at/%s/api/json/current/broadcast/%s/%s'
-            % (self.api_station, show_id, show_date), show_id)
+            % (self._API_STATION, show_id, show_date), show_id)
 
         entries = []
         for info in data['streams']:
@@ -182,7 +182,7 @@ class ORFRadioIE(InfoExtractor):
             duration = end - start if end and start else None
             entries.append({
                 'id': loop_stream_id.replace('.mp3', ''),
-                'url': 'http://loopstream01.apa.at/?channel=%s&id=%s' % (self.loop_station, loop_stream_id),
+                'url': 'http://loopstream01.apa.at/?channel=%s&id=%s' % (self._LOOP_STATION, loop_stream_id),
                 'title': title,
                 'description': clean_html(data.get('subtitle')),
                 'duration': duration,
@@ -204,8 +204,8 @@ class ORFFM4IE(ORFRadioIE):
     IE_NAME = 'orf:fm4'
     IE_DESC = 'radio FM4'
     _VALID_URL = r'https?://(?P<station>fm4)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>4\w+)'
-    api_station = "fm4"
-    loop_station = "fm4"
+    _API_STATION = 'fm4'
+    _LOOP_STATION = 'fm4'
 
     _TEST = {
         'url': 'http://fm4.orf.at/player/20170107/4CC',
@@ -228,8 +228,8 @@ class ORFNOEIE(ORFRadioIE):
     IE_NAME = 'orf:noe'
     IE_DESC = 'Radio Niederösterreich'
     _VALID_URL = r'https?://(?P<station>noe)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "noe"
-    loop_station = "oe2n"
+    _API_STATION = 'noe'
+    _LOOP_STATION = 'oe2n'
 
     _TEST = {
         'url': 'https://noe.orf.at/player/20200423/NGM',
@@ -241,8 +241,8 @@ class ORFWIEIE(ORFRadioIE):
     IE_NAME = 'orf:wien'
     IE_DESC = 'Radio Wien'
     _VALID_URL = r'https?://(?P<station>wien)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "wie"
-    loop_station = "oe2w"
+    _API_STATION = 'wie'
+    _LOOP_STATION = 'oe2w'
 
     _TEST = {
         'url': 'https://wien.orf.at/player/20200423/WGUM',
@@ -254,8 +254,8 @@ class ORFBGLIE(ORFRadioIE):
     IE_NAME = 'orf:burgenland'
     IE_DESC = 'Radio Burgenland'
     _VALID_URL = r'https?://(?P<station>burgenland)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "bgl"
-    loop_station = "oe2b"
+    _API_STATION = 'bgl'
+    _LOOP_STATION = 'oe2b'
 
     _TEST = {
         'url': 'https://burgenland.orf.at/player/20200423/BGM',
@@ -267,8 +267,8 @@ class ORFOOEIE(ORFRadioIE):
     IE_NAME = 'orf:oberoesterreich'
     IE_DESC = 'Radio Oberösterreich'
     _VALID_URL = r'https?://(?P<station>ooe)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "ooe"
-    loop_station = "oe2o"
+    _API_STATION = 'ooe'
+    _LOOP_STATION = 'oe2o'
 
     _TEST = {
         'url': 'https://ooe.orf.at/player/20200423/OGMO',
@@ -280,8 +280,8 @@ class ORFSTMIE(ORFRadioIE):
     IE_NAME = 'orf:steiermark'
     IE_DESC = 'Radio Steiermark'
     _VALID_URL = r'https?://(?P<station>steiermark)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "stm"
-    loop_station = "oe2st"
+    _API_STATION = 'stm'
+    _LOOP_STATION = 'oe2st'
 
     _TEST = {
         'url': 'https://steiermark.orf.at/player/20200423/STGMS',
@@ -293,8 +293,8 @@ class ORFKTNIE(ORFRadioIE):
     IE_NAME = 'orf:kaernten'
     IE_DESC = 'Radio Kärnten'
     _VALID_URL = r'https?://(?P<station>kaernten)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "ktn"
-    loop_station = "oe2k"
+    _API_STATION = 'ktn'
+    _LOOP_STATION = 'oe2k'
 
     _TEST = {
         'url': 'https://kaernten.orf.at/player/20200423/KGUMO',
@@ -306,8 +306,8 @@ class ORFSBGIE(ORFRadioIE):
     IE_NAME = 'orf:salzburg'
     IE_DESC = 'Radio Salzburg'
     _VALID_URL = r'https?://(?P<station>salzburg)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "sbg"
-    loop_station = "oe2s"
+    _API_STATION = 'sbg'
+    _LOOP_STATION = 'oe2s'
 
     _TEST = {
         'url': 'https://salzburg.orf.at/player/20200423/SGUM',
@@ -319,8 +319,8 @@ class ORFTIRIE(ORFRadioIE):
     IE_NAME = 'orf:tirol'
     IE_DESC = 'Radio Tirol'
     _VALID_URL = r'https?://(?P<station>tirol)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "tir"
-    loop_station = "oe2t"
+    _API_STATION = 'tir'
+    _LOOP_STATION = 'oe2t'
 
     _TEST = {
         'url': 'https://tirol.orf.at/player/20200423/TGUMO',
@@ -332,8 +332,8 @@ class ORFVBGIE(ORFRadioIE):
     IE_NAME = 'orf:vorarlberg'
     IE_DESC = 'Radio Vorarlberg'
     _VALID_URL = r'https?://(?P<station>vorarlberg)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "vbg"
-    loop_station = "oe2v"
+    _API_STATION = 'vbg'
+    _LOOP_STATION = 'oe2v'
 
     _TEST = {
         'url': 'https://vorarlberg.orf.at/player/20200423/VGUM',
@@ -345,8 +345,8 @@ class ORFOE3IE(ORFRadioIE):
     IE_NAME = 'orf:oe3'
     IE_DESC = 'Radio Österreich 3'
     _VALID_URL = r'https?://(?P<station>oe3)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "oe3"
-    loop_station = "oe3"
+    _API_STATION = 'oe3'
+    _LOOP_STATION = 'oe3'
 
     _TEST = {
         'url': 'https://oe3.orf.at/player/20200424/3WEK',
@@ -358,8 +358,8 @@ class ORFOE1IE(ORFRadioIE):
     IE_NAME = 'orf:oe1'
     IE_DESC = 'Radio Österreich 1'
     _VALID_URL = r'https?://(?P<station>oe1)\.orf\.at/player/(?P<date>[0-9]+)/(?P<show>\w+)'
-    api_station = "oe1"
-    loop_station = "oe1"
+    _API_STATION = 'oe1'
+    _LOOP_STATION = 'oe1'
 
     _TEST = {
         'url': 'http://oe1.orf.at/player/20170108/456544',