diff --git a/chirp/drivers/retevis_rt21.py b/chirp/drivers/retevis_rt21.py
index b060eea0..abc346e9 100644
--- a/chirp/drivers/retevis_rt21.py
+++ b/chirp/drivers/retevis_rt21.py
@@ -839,8 +839,16 @@ def get_raw_memory(self, number):
         return repr(self._memobj.memory[number - 1])
 
     def _get_tone(self, _mem, mem):
+        # 0xA662 = 662R = 1010 0...
+        # 0xA9DC = 734R = 1010 1...
+        # 0x29D3 = 723N - 0010 1...
+
         def _get_dcs(val):
-            code = int("%03o" % (val & 0x07FF))
+            if val & 0x0800:
+                code = int("%03o" % (val & 0x07FF))
+            else:
+                # 0x0800 means code is stored in hex instead of ocal (?!)
+                code = int("%03x" % (val & 0x07FF))
             pol = (val & 0x8000) and "R" or "N"
             return code, pol