The method of generating AM with a SSB transmitter by reinserting carrier was a common mode of operation in the late 50's and early 60's. The TV video signal works this way.
It is my understanding the modern RICEBOXES that generate AM do it in the exact way. I know it is not real AM but may people just don't have access to a good Johnson transmitter or DX-100. Bob Macklin K5MYJ Seattle, Wa, "Real Radios Glow in the Dark" ----- Original Message ----- From: "D. Chester" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, February 07, 2008 3:22 PM Subject: [AMRadio] Re: Carrier with one sideband > > > From: Peter Markavage <[EMAIL PROTECTED]> > > > A number of the early phasing type transmitters/exciters and SSB adapters > > allowed you to operate on "AM" with just one sideband. So, only operating > > DSB AM would really be an issue. > > > >> From: "Bob Macklin" <[EMAIL PROTECTED]> > > > Any of the Heath SSB rigs (SB-100/101, SB-400/401, HW-100/101) could be > > modified to Vestigial SB. SSB with carrier reinserted. > > > > Bob Macklin > > K5MYJ > > > SSB with the carrier re-inserted is not the same thing as what we know as > AM. It is nothing more than SSB with poor carrier suppression. Reception > with an envelope detector inherently generates severe distortion at > modulation levels beyond about 20%. This mode is useful only with a > receiver with BFO that locks onto the "pilot carrier" to eliminate frequency > error in SSB reception, a technique that has in fact long been used in > commercial services, with the carrier level reduced to about 20 dB below > p.e.p. At modulation levels low enough to avert this distortion, known as > "quadrature distortion" it is very wasteful of power since the sideband > power becomes a very small percentage of total radiated power. Those > amateur SSB rigs that transmit "AM" with carrier and one sideband sound like > CRAP. Unless the receiving station is equipped with a proper receiver with > PLL carrier reinsertion, which includes very few amateur receivers, it is a > totally useless mode beyond simply getting someone's attention when they are > receiving in AM mode, in order that they may switch the receiver over to SSB > to receive the signal in normal SSB fashion. > > This problem is inherent to the principles of modulation, and has nothing to > do with the quality of the equipment used. Transmitting AM with one > sideband is NOT a solution to the problem nor is it even a satisfactory > option. > > 73, > > Don k4kyv > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > To unsubscribe, send an email to [EMAIL PROTECTED] with > the word unsubscribe in the message body. > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected] To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
