In a message dated 9/1/07 8:07:53 PM Eastern Daylight Time, [EMAIL PROTECTED] writes:
> Some are suggesting the less than 180° Class C amplification method is > what CBs use. I understand this requires a good tank circuit to > complete the sine waves, but is supposedly inappropriate for amplitude > style modulations like AM, DSB and SSB. It depends. Modes like DSB and SSB are usually generated at a low level at a fixed frequency, then heterodyned and amplified to the operating frequency. All stages in such a transmitter must be linear, which means Class A, AB, or B. Class C is right out because it's not linear. AM is different. Some AM rigs generate the signal in a manner similar to DSB or SSB, and in such cases the stages must be linear. But AM can also be generated by modulating the final stage of the transmitter. In such "high level" modulation schemes, the final stage does not have to be linear, and is almost always Class C. Look at amateur AM transmitters such as the EFJohnson and Heathkit for examples of how this was done. 73 de Jim, N2EY ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
