John Huggins, kx4o wrote > > One question I have about the choice between the KAF2 and KDSP2 is what > about having neither. > > How would one describe the receiver/filter capabilities of the bare K2? >
John neither is a valid response for some situations...it all depends on your operating modes. I use my QRP K2 exclusively for field operating so take my comments with that in mind. I used the rig for several years with no filtering besides the XFIL (set for 1000/700/400/100 BWs). I then decided to add a KAF2 thinking it might add some capability, but in fact I seldom use it. I even modified the AF2 setting for low ringing per KI6WX's analysis (BTW the KI6WX link on LA3ZA's mod site no longer works). This past weekend in the QRPTTF event, conditions were such that nearly all QRP signals were at or below the very low noise floor. Very few signals would light ANY meter bars even with the preamp on. I found my best copy was using the 1000 Hz BW and no AF filtering. I tried both the KAF2's AF1 and AF2 settings several times but always returned it to off for best copy. For copying weak signals in white noise, I find my ears usually beat any DSP (e.g. K3) or analog filtering with the sole exception of the K3's APF, which can help in some situations. My ears need wide bandwidth to help discriminate weak signals from noise and the fact that APF allows this (a very sharp AF filter with gain superposed on a much wider IF bandwidth) makes it helpful in certain situations. Anyway, the K2 without additional AF filtering works well for me when copying weak signals if that's your primary operating mode. I did rediscover this weekend how much I hate (i.e. worse than dislike!) the very high distortion in the K2's sidetone which makes it difficult to match signals when zero-beating. TF3MA's mod for that is next on my K2 list: http://www.raunvis.hi.is/~matti/TF3MA/sidetone_tf3ma.html 73, Bill W4ZV -- View this message in context: http://elecraft.365791.n2.nabble.com/KAF2-or-KDSP2-for-K2-tp7517325p7519675.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
