Hello Andy,

If you want to see a REALLY ugly LF exciter, also with I/Q processing :
http://freenet-homepage.de/dl4yhf/phasing_lf_exciter/index.html


And, not as ugly as mine:
http://www.w1tag.com/Phasing.htm

John has achieved a carrier suppresion around 60 dB, or better.
A few notes about the software to drive it is also on this site.

Cheers,
 Wolf DL4YHF .


Andy Talbot schrieb:

Direct soundcard to LF upconverter; image reject mixer with allpass
phase network for a few hundred Hz bandwidth.

           http://www.g4jnt.com/LFUpconv.pdf

Around 40dBc sideband rejection, so a bit marginal for the
perfectionist but probably difficult to do very much better without an
awful lot of phase and amplitude tweaking.

Andy  G4JNT
www.g4jnt.com