[Elecraft] K3S (SDR/superhet hybrid) vs. entry-level direct-sampling radios [Correction]

[Wayne Burdick]

Gary, K7EMF, caught an error in my paragraph below. I had used ‘dB’ when I meant ‘dBm’ (dB relative to 1 milliwatt). Now corrected.

73,
Wayne
N6KR


> Such over-ranging is almost unheard of in the K3S, for multiple reasons. First, we use very strong mixers and gain stages. Second, in many cases there’s no need to turn the preamp on at all. (Example: the K3S’s preamp-off sensitivity is typically -135 dBm, while the preamp-off sensitivity on a typical direct-sampling SDR is -115 to -125 dBm.) The third reason for the K3S’s strong-signal performance is its crystal roofing filters. These protect the ADC from not only wide-spaced signals, but also from signals very close by. As K3 and K3S owners will attest, you can have a huge signal just a few hundred Hz away and not even know it’s there -- unless that station’s transmit phase noise is blanketing the band anyway. (There’s no defense against an unclean or clicky transmit signal.)