diff --git a/application/controllers/Logbookadvanced.php b/application/controllers/Logbookadvanced.php
index 617b8bbc..8f290e81 100644
--- a/application/controllers/Logbookadvanced.php
+++ b/application/controllers/Logbookadvanced.php
@@ -124,6 +124,7 @@ class Logbookadvanced extends CI_Controller {
 			'pota' => xss_clean($this->input->post('pota')),
 			'wwff' => xss_clean($this->input->post('wwff')),
 			'qslimages' => xss_clean($this->input->post('qslimages')),
+			'dupes' => xss_clean($this->input->post('dupes')),
 		);
 
 		$qsos = [];
diff --git a/application/language/bulgarian/filter_lang.php b/application/language/bulgarian/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/bulgarian/filter_lang.php
+++ b/application/language/bulgarian/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/chinese_simplified/filter_lang.php b/application/language/chinese_simplified/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/chinese_simplified/filter_lang.php
+++ b/application/language/chinese_simplified/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/czech/filter_lang.php b/application/language/czech/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/czech/filter_lang.php
+++ b/application/language/czech/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/dutch/filter_lang.php b/application/language/dutch/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/dutch/filter_lang.php
+++ b/application/language/dutch/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/english/filter_lang.php b/application/language/english/filter_lang.php
index 288364a3..02876376 100644
--- a/application/language/english/filter_lang.php
+++ b/application/language/english/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
@@ -153,4 +154,4 @@ $lang['filter_options_show'] = 'Show';
 // $lang['gen_hamradio_wwff']           --> application/language/english/general_words_lang.php
 // $lang['gen_hamradio_pota']           --> application/language/english/general_words_lang.php
 // $lang['options_save']                --> application/language/english/options_lang.php
-$lang['filter_options_close'] = 'Close';
\ No newline at end of file
+$lang['filter_options_close'] = 'Close';
diff --git a/application/language/finnish/filter_lang.php b/application/language/finnish/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/finnish/filter_lang.php
+++ b/application/language/finnish/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/french/filter_lang.php b/application/language/french/filter_lang.php
index cea415fc..94cdce6e 100644
--- a/application/language/french/filter_lang.php
+++ b/application/language/french/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Suche zurücksetzen';
diff --git a/application/language/german/filter_lang.php b/application/language/german/filter_lang.php
index 416937c9..a2bd57bb 100644
--- a/application/language/german/filter_lang.php
+++ b/application/language/german/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filter';
 $lang['filter_actions'] = 'Aktionen';
 $lang['filter_results'] = '# Resultate';
 $lang['filter_search'] = 'Suche';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Karte';
 $lang['filter_options'] = 'Optionen';
 $lang['filter_reset'] = 'Reset';
@@ -153,4 +154,4 @@ $lang['filter_options_show'] = 'Anzeigen';
 // $lang['gen_hamradio_wwff']           --> application/language/english/general_words_lang.php
 // $lang['gen_hamradio_pota']           --> application/language/english/general_words_lang.php
 // $lang['options_save']                --> application/language/english/options_lang.php
-$lang['filter_options_close'] = 'Schliessen';
\ No newline at end of file
+$lang['filter_options_close'] = 'Schliessen';
diff --git a/application/language/greek/filter_lang.php b/application/language/greek/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/greek/filter_lang.php
+++ b/application/language/greek/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/italian/filter_lang.php b/application/language/italian/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/italian/filter_lang.php
+++ b/application/language/italian/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/polish/filter_lang.php b/application/language/polish/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/polish/filter_lang.php
+++ b/application/language/polish/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/russian/filter_lang.php b/application/language/russian/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/russian/filter_lang.php
+++ b/application/language/russian/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/spanish/filter_lang.php b/application/language/spanish/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/spanish/filter_lang.php
+++ b/application/language/spanish/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/swedish/filter_lang.php b/application/language/swedish/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/swedish/filter_lang.php
+++ b/application/language/swedish/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/language/turkish/filter_lang.php b/application/language/turkish/filter_lang.php
index 288364a3..23de947f 100644
--- a/application/language/turkish/filter_lang.php
+++ b/application/language/turkish/filter_lang.php
@@ -15,6 +15,7 @@ $lang['filter_filters'] = 'Filters';
 $lang['filter_actions'] = 'Actions';
 $lang['filter_results'] = '# Results';
 $lang['filter_search'] = 'Search';
+$lang['filter_dupes'] = "Dupes";
 $lang['filter_map'] = 'Map';
 $lang['filter_options'] = 'Options';
 $lang['filter_reset'] = 'Reset';
diff --git a/application/models/Logbookadvanced_model.php b/application/models/Logbookadvanced_model.php
index 20fa1a3b..eb150267 100644
--- a/application/models/Logbookadvanced_model.php
+++ b/application/models/Logbookadvanced_model.php
@@ -7,6 +7,20 @@ class Logbookadvanced_model extends CI_Model {
 		$conditions = [];
 		$binding = [$searchCriteria['user_id']];
 
+		if ($searchCriteria['dupes'] !== '') {
+			$id_sql="select group_concat(x.qsoids separator ',') as QSO_IDs from (
+				select GROUP_CONCAT(col_primary_key separator ',') as qsoids, COL_CALL, COL_MODE, COL_SUBMODE, station_callsign, COL_SAT_NAME, COL_BAND,  min(col_time_on) Mintime, max(col_time_on) Maxtime from " . $this->config->item('table_name') . "
+				 join station_profile on " . $this->config->item('table_name') . ".station_id = station_profile.station_id where station_profile.user_id=?
+				group by col_call, col_mode, COL_SUBMODE, STATION_CALLSIGN, col_band, COL_SAT_NAME having count(*) > 1 and timediff(maxtime, mintime) < 3000) x";
+			$id_query = $this->db->query($id_sql, $searchCriteria['user_id']);
+			foreach ($id_query->result() as $id) {
+				$ids2fetch=$id->QSO_IDs;
+			}
+			if ($ids2fetch !== '') {
+				$conditions[] = "qsos.COL_PRIMARY_KEY in (".$ids2fetch.")";
+			}
+		}
+
         if ($searchCriteria['dateFrom'] !== '') {
             $from = DateTime::createFromFormat('d/m/Y', $searchCriteria['dateFrom']);
 			$from = $from->format('Y-m-d');
diff --git a/application/views/logbookadvanced/index.php b/application/views/logbookadvanced/index.php
index cf67e3b1..c1256f5e 100644
--- a/application/views/logbookadvanced/index.php
+++ b/application/views/logbookadvanced/index.php
@@ -53,6 +53,7 @@ $options = json_decode($options);
 
         <form id="searchForm" name="searchForm" action="<?php echo base_url()."index.php/logbookadvanced/search";?>"
             method="post">
+            <input type="hidden" id="dupes" name="dupes" value="">
             <div class="filterbody collapse">
                 <div class="form-row">
                     <div class="form-group col-lg-2 col-md-2 col-sm-3 col-xl">
@@ -390,6 +391,7 @@ $options = json_decode($options);
             <option value="5000">5000</option>
         </select>
         <button type="submit" class="btn btn-sm btn-primary mr-1" id="searchButton"><?php echo lang('filter_search'); ?></button>
+        <button type="button" class="btn btn-sm btn-primary mr-1" id="dupeButton"><?php echo lang('filter_dupes'); ?></button>
         <button type="button" class="btn btn-sm btn-primary mr-1" id="mapButton" onclick="mapQsos(this.form);"><?php echo lang('filter_map'); ?></button>
 		<button type="options" class="btn btn-sm btn-primary mr-1" id="optionButton"><?php echo lang('filter_options'); ?></button>
 		<button type="reset" class="btn btn-sm btn-danger mr-1" id="resetButton"><?php echo lang('filter_reset'); ?></button>
diff --git a/assets/js/sections/logbookadvanced.js b/assets/js/sections/logbookadvanced.js
index e386c14d..1acff398 100644
--- a/assets/js/sections/logbookadvanced.js
+++ b/assets/js/sections/logbookadvanced.js
@@ -283,6 +283,7 @@ $(document).ready(function () {
 				pota: this.pota.value,
 				wwff: this.wwff.value,
 				qslimages: this.qslimages.value,
+				dupes: this.dupes.value,
 			},
 			dataType: 'json',
 			success: function (data) {
@@ -502,6 +503,10 @@ $(document).ready(function () {
 		quickSearch('pota');
 	});
 
+	$('#dupeButton').click(function (event) {
+		dupeSearch();
+	});
+
 	$('#optionButton').click(function (event) {
 		$('#optionButton').prop("disabled", true);
 		$.ajax({
@@ -588,6 +593,12 @@ $(document).ready(function () {
 		});
 	});
 
+	function dupeSearch() {
+		$('#searchForm').trigger("reset");
+		$("#dupes").val("Y");
+		$('#searchForm').submit();
+	}
+
 	function quickSearch(type) {
 		var elements = $('#qsoList tbody input:checked');
 		var nElements = elements.length;
@@ -672,6 +683,7 @@ $(document).ready(function () {
 	});
 
 	$('#searchForm').on('reset', function(e) {
+		$("#dupes").val("");
 		setTimeout(function() {
 			$('#searchForm').submit();
 		});