When adding a QSO, set some fields which are not used to null

application/models/logbook_model.php

@@ -56,9 +56,23 @@ class Logbook_model extends CI_Model {
                    'COL_MY_GRIDSQUARE' => $locator,
                    'COL_DISTANCE' => "0",
                    'COL_FREQ_RX' => 0,
-           'COL_BAND_RX' => 0,
-           'COL_ANT_AZ' => '0',
-           'COL_ANT_EL' => '0',
+                   'COL_BAND_RX' => null,
+                   'COL_ANT_AZ' => null,
+                   'COL_ANT_EL' => null,
+                   'COL_A_INDEX' => null,
+                   'COL_AGE' => null,
+                   'COL_TEN_TEN' => null,
+                   'COL_TX_PWR' => null,
+                   'COL_STX' => null,
+                   'COL_SRX' => null,
+                   'COL_NR_BURSTS' => null,
+                   'COL_NR_PINGS' => null,
+                   'COL_MAX_BURSTS' => null,
+                   'COL_K_INDEX' => null,
+                   'COL_SFI' => null,
+                   'COL_RX_PWR' => null,
+                   'COL_LAT' => null,
+                   'COL_LON' => null,
 		);
 
 		$this->add_qso($data);