diff --git a/Makefile b/Makefile
index 6ea66e39..6b5d00dc 100644
--- a/Makefile
+++ b/Makefile
@@ -217,6 +217,7 @@ afsk/ax5043.o: afsk/ax25.h
 afsk/ax5043.o: afsk/ax5043.h
 afsk/ax5043.o: afsk/status.h
 afsk/ax5043.o: afsk/utils.h
+afsk/ax5043.o: afsk/main.c
 afsk/ax5043.o: ax5043/spi/ax5043spi.h
 	cd afsk; gcc -I ../ax5043 -pedantic -Wconversion -Wall -Wextra -c ax5043.c; cd ..
 
diff --git a/afsk/ax5043.c b/afsk/ax5043.c
index c4112f6a..f74b4ad9 100644
--- a/afsk/ax5043.c
+++ b/afsk/ax5043.c
@@ -34,6 +34,8 @@ static size_t __tx_buf_idx = 0;
 static uint8_t __tx_fifo_chunk[AX5043_FIFO_MAX_SIZE];
 static uint32_t __tx_remaining = 0;
 
+extern uint32_t tx_freq_hz;
+
 /**
  * FIFO command for the preamble. The third byte corresponds the length of
  * the preamble and is set by the TX routine for every frame
@@ -255,7 +257,7 @@ int ax5043_conf_tx_path(ax5043_conf_t *conf) {
         return ret;
     }
 
-    ret = ax5043_set_tx_freq(conf, TX_FREQ_HZ);
+    ret = ax5043_set_tx_freq(conf, tx_freq_hz);
     if (ret) {
         return ret;
     }
diff --git a/afsk/main.c b/afsk/main.c
index 404d1feb..675b78f2 100644
--- a/afsk/main.c
+++ b/afsk/main.c
@@ -61,6 +61,9 @@
 #define POWER 2
 #define VBATT 15
 
+uint32_t tx_freq_hz = 440310000;
+uint32_t tx_channel = 2;
+
 ax5043_conf_t hax5043;
 ax25_conf_t hax25;
 
@@ -172,6 +175,8 @@ int main(void) {
     int ret;
     uint8_t data[1024];
 
+    tx_freq_hz -= tx_channel * 50000;
+
     init_rf();
 
 //    ax25_init(&hax25, (uint8_t *) "CubeSatSim", '2', (uint8_t *) CALLSIGN, '2',
diff --git a/cw/cw_main.c b/cw/cw_main.c
index 98ec7522..83f4aa88 100644
--- a/cw/cw_main.c
+++ b/cw/cw_main.c
@@ -62,6 +62,8 @@
 #define CURRENT 1
 #define POWER 2
 
+uint32_t tx_freq_hz = 440390000;
+
 long int timestamp = 0;
 extern uint8_t axradio_rxbuffer[];
 void *transmit(void *arg);