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Jim Hampton wrote:
wrote in message oups.com... http://www.getboost.com/dz/sienna.htm Hello, Jim Greetings! Well, how about a kit in the $100.00 range ..... with opposite sideband rejection in excess of 50 dB. Even a few hundred Hz away from the carrier? Direct conversion. With selectable sideband. Hmmmm .... Of course, it is a receiver. They do make an exciter. But the thought of a phasing direct conversion receiver or phasing transmitter with sideband suppression of that order is interesting. Especially since the lower audio frequencies will also be highly suppressed. Yep. Not a new idea, there was such a receiver in QST way back in the early 1970s. The problem is that it's not a $100 kit. You have: - the basic R2 board - the DSP board - a VFO (probably DDS to generate the I and Q signals) - the T2 board - a housing and control system for the whole setup *Each* of those will run you $100 or so if made from new parts. And what you get is a QRP monobander. More bands and more power will add considerably to the cost. And pretty soon you wind up with something that costs as much as an Elecraft K2/100. I've got the QSTs referenced. All in the 1990s. Of course, they've replaced the analog audio quadrature generation with DSP to obtain the increase from 40 to 50+ dB suppression of the unwanted sideband. Here is a URL: http://www.wwc.edu/~frohro/R2_DSP/R2-DSP.html Nothing like DSP. 50 dB unwanted sideband rejection on receive isn't *that* great, though. The Ancient Ones did better a half-century or more ago. But it *is* a neat rig. N7VE's Tayloe Mixer was featured in a Red Hot Radio 30 meter CW transceiver. But it's not available now, last I looked. --- OTOH, a lot of rig can be built for $100 if you use other than new parts from sources like hamfests: http://hometown.aol.com/n2ey/myhomepage/index.html 73 de Jim, N2EY |