000  $anz n  2
000  $a주제어
001  $aKSH1998028485
005  $a20021220000000
008  $a980429 n azknnaabn          |a a|a    | 
150  $a평형 복조기[平衡復調器]
450  $wr$i영어$abalanced demodulator
550  $wg$a복조기[復調器]
550  $a모뎀[modem]
550  $a평형 변조기[平衡變調器]