diff --git a/src/TEF6686.h b/src/TEF6686.h
index b35d9a6..5514889 100644
--- a/src/TEF6686.h
+++ b/src/TEF6686.h
@@ -47,8 +47,8 @@ enum RADIO_TUNE_MODE {
 #define FREQ_SW_HIGH_EDGE_MAX      (FREQ_SW_END)
 #define FREQ_FM_START              65000
 #define FREQ_FM_END                108000
-#define FREQ_FM_OIRT_START         6540
-#define FREQ_FM_OIRT_END           7800
+#define FREQ_FM_OIRT_START         6575   // use values of 1/10 * kHz
+#define FREQ_FM_OIRT_END           7400   // use values of 1/10 * kHz
 
 // according to https://www.short-wave.info/index.php?feature=frequencies
 #define FREQ_SW_START       1800
@@ -275,4 +275,4 @@ class TEF6686 {
     bool rtABold;
     wchar_t PStext[9] = L"";
     byte ps_counter;
-};
\ No newline at end of file
+};