From the source code, you can clearly understand how the base band signal can be modulated to the radio frequency by FM and AM. In addition, you can use filtering to check the change of power spectrum density of subcarrier.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001336s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.098420s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001230s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001902s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001222s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003634s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001047s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003199s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014503s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001357s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 7760 [ RunTime:0.001157s ]
