diff --git a/protocol/esta/analog/transmitter.h b/protocol/esta/analog/transmitter.h
index 5aa6c5c..e551552 100644
--- a/protocol/esta/analog/transmitter.h
+++ b/protocol/esta/analog/transmitter.h
@@ -38,6 +38,7 @@ struct Transmitter
    * full on condition.
    */
   const int16_t zero     =     0; //!< mV,  0.0 V
+  const int16_t zero_max =   200; //!< mv,  0.2 V
   const int16_t full     = 10000; //!< mV, 10.0 V
 
   /**
@@ -46,7 +47,11 @@ struct Transmitter
    * @return
    */
   int16_t millivolts(uint8_t level) const {
-    return full * (level / UINT8_MAX);
+    if (level == 0)
+      return zero;
+    if (level == UINT8_MAX)
+      return full;
+    return ((full - zero_max) * (level / UINT8_MAX)) + zero_max;
   };
 };