Hi all, I'm evaluating my rig on the bench with a sig gen and have a few questions regarding image rejection...
I am finding that the image rejection is not consistent from band to band. I can optimize on each band with a different set of values. Is this normal? It would be nice to be able to store seperate values for each band if so. My offsets are: ............... 60m....40m....20m.......15m.......10m phase.......-.89.....-1.11...-2.08.......0.02.......-5.44 gain......... 6.8.....7.05.....5.14.......6.61.......19.33 How much image rejection should I expect? I'm adusting it by tuning the sig gen to the image frequency and then nulling the received signal. I can acheive >70dB null. This is not the optimum for the observed image on the panadapter screen when tuned to the wanted signal - it is only ~ 60dB down. Also, I have a noise spike in the center of the panadapter (corresponding to DC). Its level bounces and it is at a reported ~ -80dBm to -115dBm depending on the preamp gain setting. I susspect this is AC 60Hz hum getting into the IQ audio. Is this normal? When I play the wave files from the flex site I do not see this which makes me susspect a ground loop or something. Thanks for any advice... David KM5TZ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060513/0162a72b/attachment.html _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
