diff --git a/src/libsdr/sdr.c b/src/libsdr/sdr.c
index 5ef8ffb..6d41e53 100644
--- a/src/libsdr/sdr.c
+++ b/src/libsdr/sdr.c
@@ -167,11 +167,6 @@ void *sdr_open(const char __attribute__((__unused__)) *device, double *tx_freque
 	if (bandwidth)
 		PDEBUG(DSDR, DEBUG_INFO, "Require bandwidth of each channel is 2 * (%.1f deviation + %.1f modulation) = %.1f KHz\n", max_deviation / 1e3, max_modulation / 1e3, bandwidth / 1e3);
 
-	if (channels < 1) {
-		PDEBUG(DSDR, DEBUG_ERROR, "No channel given, please fix!\n");
-		abort();
-	}
-
 	sdr = calloc(sizeof(*sdr), 1);
 	if (!sdr) {
 		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
@@ -261,10 +256,12 @@ void *sdr_open(const char __attribute__((__unused__)) *device, double *tx_freque
 	}
 
 	/* create list of channel states */
-	sdr->chan = calloc(sizeof(*sdr->chan), channels + (sdr->paging_channel != 0));
-	if (!sdr->chan) {
-		PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
-		goto error;
+	if (channels) {
+		sdr->chan = calloc(sizeof(*sdr->chan), channels + (sdr->paging_channel != 0));
+		if (!sdr->chan) {
+			PDEBUG(DSDR, DEBUG_ERROR, "NO MEM!\n");
+			goto error;
+		}
 	}
 
 	/* swap links, if required */
@@ -276,7 +273,9 @@ void *sdr_open(const char __attribute__((__unused__)) *device, double *tx_freque
 		tx_frequency = temp;
 	}
 
-	if (tx_frequency) {
+	if (tx_frequency && !channels)
+		tx_center_frequency = tx_frequency[0];
+	if (tx_frequency && channels) {
 		/* calculate required bandwidth (IQ rate) */
 
 		double tx_low_frequency = 0.0, tx_high_frequency = 0.0;
@@ -357,7 +356,9 @@ void *sdr_open(const char __attribute__((__unused__)) *device, double *tx_freque
 		}
 	}
 
-	if (rx_frequency) {
+	if (rx_frequency && !channels)
+		rx_center_frequency = rx_frequency[0];
+	if (rx_frequency && channels) {
 		/* calculate required bandwidth (IQ rate) */
 		double rx_low_frequency = 0.0, rx_high_frequency = 0.0;
 		for (c = 0; c < channels; c++) {
diff --git a/src/libsdr/soapy.c b/src/libsdr/soapy.c
index 56c42d9..4acf477 100644
--- a/src/libsdr/soapy.c
+++ b/src/libsdr/soapy.c
@@ -99,7 +99,7 @@ int soapy_open(size_t channel, const char *_device_args, const char *_stream_arg
 
 	use_time_stamps = timestamps;
 	if (use_time_stamps && (1000000000LL % (long long)rate)) {
-		PDEBUG(DSOAPY, DEBUG_ERROR, "The given sample duration is not a multiple of a nano second. I.e. we can't divide 1000,000,000 by sample rate of %.0f. Please choose a different sample rate for time stamp support!\n", rate);
+		PDEBUG(DSOAPY, DEBUG_ERROR, "The given sample duration is not a multiple of a nano second. I.e. we can't divide 10^9 by sample rate of %.0f. Please choose a different sample rate for time stamp support!\n", rate);
 		use_time_stamps = 0;
 	}
 	Ns_per_sample = 1000000000LL / (long long)rate;
diff --git a/src/radio/main.c b/src/radio/main.c
index b45d106..b58108f 100644
--- a/src/radio/main.c
+++ b/src/radio/main.c
@@ -393,7 +393,7 @@ int main(int argc, char *argv[])
 	tx_frequencies[0] = frequency;
 	rx_frequencies[0] = frequency;
 	am[0] = 0;
-	sdr = sdr_open(NULL, tx_frequencies, rx_frequencies, am, 1, 0.0, dsp_samplerate, buffer_size, 1.0, 0.0, 0.0, 0.0);
+	sdr = sdr_open(NULL, tx_frequencies, rx_frequencies, am, 0, 0.0, dsp_samplerate, buffer_size, 1.0, 0.0, 0.0, 0.0);
 	if (!sdr)
 		goto error;
 	sdr_start(sdr);
diff --git a/src/tv/main.c b/src/tv/main.c
index e8ded74..c46b9d6 100644
--- a/src/tv/main.c
+++ b/src/tv/main.c
@@ -228,7 +228,7 @@ static int handle_options(int short_option, int argi, char **argv)
 				"--sdr-tx-gain", "50",
 				"--sdr-lo-offset", "-3000000",
 				"--sdr-bandwidth", "60000000",
-				"-s", "13750000",
+				"-s", "12500000",
 			};
 			int argc_lime = sizeof(argv_lime) / sizeof (*argv_lime);
 			return options_command_line(argc_lime, argv_lime, handle_options);
@@ -242,7 +242,7 @@ static int handle_options(int short_option, int argi, char **argv)
 				"--sdr-tx-gain", "50",
 				"--sdr-lo-offset", "-3000000",
 				"--sdr-bandwidth", "60000000",
-				"-s", "13750000",
+				"-s", "12500000",
 			};
 			int argc_lime = sizeof(argv_lime) / sizeof (*argv_lime);
 			return options_command_line(argc_lime, argv_lime, handle_options);
@@ -333,7 +333,7 @@ static void tx_bas(sample_t *sample_bas, __attribute__((__unused__)) sample_t *s
 		tx_frequencies[0] = frequency;
 		rx_frequencies[0] = frequency;
 		am[0] = 0;
-		sdr = sdr_open(NULL, tx_frequencies, rx_frequencies, am, 1, 0.0, dsp_samplerate, buffer_size, 1.0, 0.0, 0.0, 0.0);
+		sdr = sdr_open(NULL, tx_frequencies, rx_frequencies, am, 0, 0.0, dsp_samplerate, buffer_size, 1.0, 0.0, 0.0, 0.0);
 		if (!sdr)
 			goto error;
 		sdr_start(sdr);