> From: "Larry Szendrei" <[email protected]> >>> There have been some interesting cases with short loaded antennas >> in the BC band, the bandwidth has occasionally been so narrow that the AM >> sidebands become attenuated! Not going to see that effect in the amateur >> bands unless someone is running an antenna only a few feet long!! > > Correct. This has been observed on my 75M AM mobile signal, with reports > of one sideband being attenuated relative to the other. Antenna is a > Webster bandpanner ("a few feet long"). > > 73, > -Larry/NE1S
The first commercial use of SSB was around 1920 for transatlantic telephone links using VLF. Even the tallest tower in the world would be only a tiny fraction of a wave length at those frequencies. The bandwidth was too narrow to pass both sidebands, but they found that they could get by transmitting only one. Thus, the sideband filter was the antenna itself! The balanced modulator circuit was known during the WW1 era. I have seen descriptions of the circuit in old radio books of that day. The first SSB ham rig was described in a series of construction articles in R/9 magazine in 1933 and 1934. I have the issues with the articles. A lot of to-day's Hammy Hambones think that SSB was invented during or shortly after WW2. Don k4kyv _______________________________________________________________ This message was typed using the DVORAK keyboard layout. http://www.mwbrooks.com/dvorak/ http://gigliwood.com/abcd/ ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
