Advanced Filters
                                
                                
                                    
                                        
                                        
                                    
                                    
                                        
                                        
                                    
                                     lang('gen_hamradio_propagation_AS'),
                                                       'AUR' => lang('gen_hamradio_propagation_AUR'),
                                                       'AUE' => lang('gen_hamradio_propagation_AUE'),
                                                       'BS' => lang('gen_hamradio_propagation_BS'),
                                                       'ECH' => lang('gen_hamradio_propagation_ECH'),
                                                       'EME' => lang('gen_hamradio_propagation_EME'),
                                                       'ES' => lang('gen_hamradio_propagation_ES'),
                                                       'FAI' => lang('gen_hamradio_propagation_FAI'),
                                                       'F2' => lang('gen_hamradio_propagation_F2'),
                                                       'INTERNET' => lang('gen_hamradio_propagation_INTERNET'),
                                                       'ION' => lang('gen_hamradio_propagation_ION'),
                                                       'IRL' => lang('gen_hamradio_propagation_IRL'),
                                                       'MS' => lang('gen_hamradio_propagation_MS'),
                                                       'RPT' => lang('gen_hamradio_propagation_RPT'),
                                                       'RS' => lang('gen_hamradio_propagation_RS'),
                                                       'SAT' => lang('gen_hamradio_propagation_SAT'),
                                                       'TEP' => lang('gen_hamradio_propagation_TEP'),
                                                       'TR' => lang('gen_hamradio_propagation_TR')];
                                        asort($prop_modes);
                                    ?>