diff --git a/lib/rtl/rtl_source_c.cc b/lib/rtl/rtl_source_c.cc
index 794d4f7..483ca15 100644
--- a/lib/rtl/rtl_source_c.cc
+++ b/lib/rtl/rtl_source_c.cc
@@ -312,16 +312,16 @@ osmosdr::meta_range_t rtl_source_c::get_sample_rates()
 {
   osmosdr::meta_range_t range;
 
+  range += osmosdr::range_t( 1000000 ); // known to work
   range += osmosdr::range_t( 1024000 ); // known to work
   range += osmosdr::range_t( 1800000 ); // known to work
+  range += osmosdr::range_t( 1920000 ); // known to work
   range += osmosdr::range_t( 2048000 ); // known to work
-  range += osmosdr::range_t( 2400000 ); // may work
+  range += osmosdr::range_t( 2400000 ); // known to work
   range += osmosdr::range_t( 2600000 ); // may work
   range += osmosdr::range_t( 2800000 ); // may work
   range += osmosdr::range_t( 3000000 ); // may work
-  range += osmosdr::range_t( 3200000 ); // max rate, may work
-
-  // TODO: read from the librtlsdr as soon as the api is available
+  range += osmosdr::range_t( 3200000 ); // max rate
 
   return range;
 }
@@ -347,9 +347,20 @@ osmosdr::freq_range_t rtl_source_c::get_freq_range( size_t chan )
 {
   osmosdr::freq_range_t range;
 
-  range += osmosdr::range_t( 50e6, 2.2e9, 100 );
+  if (_dev) {
+    enum rtlsdr_tuner tuner = rtlsdr_get_tuner_type(_dev);
 
-  // TODO: read from the librtlsdr as soon as the api is available
+    if ( tuner == RTLSDR_TUNER_E4000 ) {
+      /* there is a (temperature dependent) gap between 1100 to 1250 MHz */
+      range += osmosdr::range_t( 50e6, 2.2e9, 100 );
+    } else if ( tuner == RTLSDR_TUNER_FC0012 ) {
+      /* range += osmosdr::range_t( 50e6, 2.2e9, 100 ); */
+    } else if ( tuner == RTLSDR_TUNER_FC0013 ) {
+      /* range += osmosdr::range_t( 50e6, 2.2e9, 100 ); */
+    } else if ( tuner == RTLSDR_TUNER_FC2580 ) {
+      /* range += osmosdr::range_t( 50e6, 2.2e9, 100 ); */
+    }
+  }
 
   return range;
 }
@@ -399,26 +410,15 @@ osmosdr::gain_range_t rtl_source_c::get_gain_range( size_t chan )
 {
   osmosdr::gain_range_t range;
 
-  range += osmosdr::range_t( -1.0 );
-  range += osmosdr::range_t( 1.5 );
-  range += osmosdr::range_t( 4.0 );
-  range += osmosdr::range_t( 6.5 );
-  range += osmosdr::range_t( 9.0 );
-  range += osmosdr::range_t( 11.5 );
-  range += osmosdr::range_t( 14.0 );
-  range += osmosdr::range_t( 16.5 );
-  range += osmosdr::range_t( 19.0 );
-  range += osmosdr::range_t( 21.5 );
-  range += osmosdr::range_t( 24.0 );
-  range += osmosdr::range_t( 29.0 );
-  range += osmosdr::range_t( 34.0 );
-  range += osmosdr::range_t( 42.0 );
-  range += osmosdr::range_t( 43.0 );
-  range += osmosdr::range_t( 45.0 );
-  range += osmosdr::range_t( 47.0 );
-  range += osmosdr::range_t( 49.0 );
-
-  // TODO: read from the librtlsdr as soon as the api is available
+  if (_dev) {
+    int count = rtlsdr_get_tuner_gains(_dev, NULL);
+    if (count > 0) {
+      int gains[ count ];
+      count = rtlsdr_get_tuner_gains(_dev, gains);
+      for (int i = 0; i < count; i++)
+        range += osmosdr::range_t( gains[i] / 10.0 );
+    }
+  }
 
   return range;
 }
diff --git a/lib/rtl_tcp/rtl_tcp_source_c.cc b/lib/rtl_tcp/rtl_tcp_source_c.cc
index 1960f7b..f5fb58b 100644
--- a/lib/rtl_tcp/rtl_tcp_source_c.cc
+++ b/lib/rtl_tcp/rtl_tcp_source_c.cc
@@ -120,14 +120,16 @@ osmosdr::meta_range_t rtl_tcp_source_c::get_sample_rates( void )
 {
   osmosdr::meta_range_t range;
 
+  range += osmosdr::range_t( 1000000 ); // known to work
   range += osmosdr::range_t( 1024000 ); // known to work
   range += osmosdr::range_t( 1800000 ); // known to work
+  range += osmosdr::range_t( 1920000 ); // known to work
   range += osmosdr::range_t( 2048000 ); // known to work
-  range += osmosdr::range_t( 2400000 ); // may work
+  range += osmosdr::range_t( 2400000 ); // known to work
   range += osmosdr::range_t( 2600000 ); // may work
   range += osmosdr::range_t( 2800000 ); // may work
   range += osmosdr::range_t( 3000000 ); // may work
-  range += osmosdr::range_t( 3200000 ); // max rate, may work
+  range += osmosdr::range_t( 3200000 ); // max rate
 
   return range;
 }
@@ -148,6 +150,8 @@ double rtl_tcp_source_c::get_sample_rate( void )
 
 osmosdr::freq_range_t rtl_tcp_source_c::get_freq_range( size_t chan )
 {
+  // FIXME: assumption on E4000 tuner
+
   osmosdr::freq_range_t range(50e6, 2.2e6, 100);
 
   return range;
@@ -190,6 +194,8 @@ osmosdr::gain_range_t rtl_tcp_source_c::get_gain_range( size_t chan )
 {
   osmosdr::gain_range_t range;
 
+  // FIXME: assumption on E4000 tuner
+
   range += osmosdr::range_t( -1.0 );
   range += osmosdr::range_t( 1.5 );
   range += osmosdr::range_t( 4.0 );