diff --git a/csdr/chain/dump1090.py b/csdr/chain/dump1090.py
index ef4989a..04a2942 100644
--- a/csdr/chain/dump1090.py
+++ b/csdr/chain/dump1090.py
@@ -22,3 +22,6 @@ class Dump1090(ServiceDemodulator):
 
     def isSecondaryFftShown(self):
         return False
+
+    def supportsSquelch(self) -> bool:
+        return False
diff --git a/csdr/chain/dumphfdl.py b/csdr/chain/dumphfdl.py
index f6a29c4..413b615 100644
--- a/csdr/chain/dumphfdl.py
+++ b/csdr/chain/dumphfdl.py
@@ -11,3 +11,6 @@ class DumpHFDL(ServiceDemodulator):
 
     def getFixedAudioRate(self) -> int:
         return 12000
+
+    def supportsSquelch(self) -> bool:
+        return False
diff --git a/csdr/chain/dumpvdl2.py b/csdr/chain/dumpvdl2.py
index 809a690..cae271f 100644
--- a/csdr/chain/dumpvdl2.py
+++ b/csdr/chain/dumpvdl2.py
@@ -14,3 +14,6 @@ class DumpVDL2(ServiceDemodulator):
 
     def getFixedAudioRate(self) -> int:
         return 105000
+
+    def supportsSquelch(self) -> bool:
+        return False
diff --git a/csdr/chain/rtl433.py b/csdr/chain/rtl433.py
index f1f9534..e0fa685 100644
--- a/csdr/chain/rtl433.py
+++ b/csdr/chain/rtl433.py
@@ -14,3 +14,6 @@ class Rtl433(ServiceDemodulator):
                 JsonParser("ISM"),
             ]
         )
+
+    def supportsSquelch(self) -> bool:
+        return False