diff --git a/afsk/main.c b/afsk/main.c
index 7bbb728e..ef6d95d6 100644
--- a/afsk/main.c
+++ b/afsk/main.c
@@ -302,7 +302,21 @@ mode = AFSK;
           onLedOn = HIGH;
           onLedOff = LOW;
           transmit = TRUE;
-        }
+        } else {
+       	pinMode(23, INPUT);
+        pullUpDnControl(23, PUD_UP);
+
+        if (digitalRead(23) != HIGH) {
+          printf("vB5 Present with VHF BPF\n");
+          txLed = 2;
+          txLedOn = HIGH;
+          txLedOff = LOW;
+          vB5 = TRUE;
+          onLed = 27;
+          onLedOn = HIGH;
+          onLedOff = LOW;
+          transmit = TRUE;
+	}
       }
     }
   }