+/** regulate distance using variable resistor, values for low tx power */
+#define RF_LOTX_DAMPING_0dB 255
+#define RF_LOTX_DAMPING_5dB 90
+#define RF_LOTX_DAMPING_10dB 67
+#define RF_LOTX_DAMPING_15dB 50
+#define RF_LOTX_DAMPING_16dB 40
+#define RF_LOTX_DAMPING_17dB 30
+
+// choose one
+#define INITIAL_RF_POWER RF_HITX_DAMPING_0dB