I'm curious - during the contest, with all the strong signals, I can hear
(way down, not a big deal for ultimate copy at all) the beat note between
two strong signals in the passband (CW). Well, it appears to be a beat
note, I haven't added or subtracted the frequencies, but it is a third
tone above both tones in the passband. It is not easy to reproduce, has
to be strong signals positioned in the wide filter passband, not always
easy to hear (I have noticed it on other OMNI VI's but could not just make
it happen so I could notice its parameters). I suppose I should inject
two strong signals into my OMNI VI and just create it and look at it. Is
this likely to come from the product detector (the last mixer the yields
the audio products) ? I ought to go look at the definitions of the mixing
products... just interesting to me.
Clark
WA3JPG
|