Hi Larry That can be done, If you remove only one sideband from AM
however a lot of power must be transmitted to have the carier. AM: 1/4 of peak power in LSB 1/2 of peak power in carrier 1/4 of peak power in USB Its not only a bandwidth story but also power efficiency. It is possible to reduce the carrier power too (they do something like that in television transmission) With enough carrier power (more than 1/2 of pp) one can use a AM detector after filtering the carrier and sideband. With lower carrier power you can use the carrier to lock the oscillator in the SSB detector. I own a military transceiver that can make pseudo AM by adding the carrier frequency again after the LSB/USB filters. It works...... 73 peter pa0pvn groeten Peter petervn(a)hetnet.nl <mailto:[EMAIL PROTECTED]> ; pa0pvn(a)hetnet.nl <mailto:[EMAIL PROTECTED]> ; pa0pvn(a)gmail.com ; pa0pvn(a)amsat.org . ________________________________ Van: [EMAIL PROTECTED] namens Larry W8ER Verzonden: wo 20-12-2006 4:37 Aan: Reflector Flex Onderwerp: [Flexradio] SSB with Carrier? One of the main objections to AM is that the mode requires twice the spectrum space as SSB. One of the strengths of AM is that the audio from a transmitted signal is recovered perfectly because the carrier that produces the RF/Audio mix is sent also. This makes the decoding or detection of the audio an absolutely perfect reproduction of the original signal. Since the USB and LSB are also transmitted the signal is, in fact twice as wide. The additional sideband is truly excessive as they are mirror images of one another and all that is necessary to demodulate the signal is the carrier and ONE sideband. Many of the SSB Collins transmitters of old simulate AM by simply reinserting the carrier and transmitting it with the one sideband. Most AM operator can tell no difference when listening to such a signal! My question is, how much additional trouble would it be to develope an additional mode that sends one sideband and the carrier? This would erase the objections of double bandwidth and yet retain the perfect demodulation that AM'ers love so much. Since the information in the second sideband is redundant, it would be a perfect solution to all of the arguments! --Larry W8ER -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/flexradio_flex-radio.biz/attachments/20061219/d3dd8d68/attachment.html _______________________________________________ FlexRadio mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com <http://www.flex-radio.com/> -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/flexradio_flex-radio.biz/attachments/20061220/f1b00d35/attachment.html _______________________________________________ FlexRadio mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
