It was just over a year ago that there was a long thread about FM and PM. Someone posted a link to a short magazine article (Ham Radio, it seems it was, but not sure) that shed light on the fact that PM was the first popular method of modulation for land mobile use. I've searched the archives of this list, but could not find it back. Maybe someone remembers and could re-post it??
Laryn K8TVZ --- In [email protected], [EMAIL PROTECTED] wrote: > Hi Joe, > > You want us to believe that PM is why we Pre-emp FM. > > Yup. It's a PM world, and you must make your FM equipment work in that world. > > > That's simply not the case. This is not supported by > anything I have ever seen or read, only by you. > > These are conclusions we drew from old documents from the 40s. We don't have > anything firmer than that, nor have we seen anything that implies preemphasis > was intentionally added to a flat system by any standards body. > > While I do agree that preemphasis improves intelligibility, again there is no > evidence it was added with malice and forethought. > > I would request that if you, or anyone, has any written material at all that > sheds light on how PM and FM came to be, share it with the group. > > Frankly, we don't even know how 455 kHz became an IF standard - - but > somebody, a long time ago, picked it and it stuck. These things happen. > > 73, > Bob Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
