DNA extraction problems - bacteriophage

i failed miserably to extract dna from my bacteriophages. i had 59 phages against pseudomonas aeruginosa isolates and 44 phages against salmonella enterica and 4 against enteroccous faecalis and 4 against e.coli bacteria. from high titre lysate i first tried to extract dna but the concentration was too less for sequecing. then i tried concentration using centrifugal filtration where i got reasoably good concentration for sequencing. 20-30% of my phages are sequenced and 70% are not sequenced. i am almost done with research but i am curious what went wrong from my side. also i feel i was a bad researcher