Your explanation of the issues surrounding QSK in the K3 is well worth the read, Guy, and I thank you for it. I’ll stop quibbling about milliseconds on the T-R change-over. :-)
I am not a QRQ operator, far from it; I top out at around 30-35 WPM for rag-chew copy in my head. But in regular QSK mode with default settings (8 ms delay, etc.), I do find it difficult to hear a weak DX station coming back between my bauds. Your attribution of this to wetware factors is compelling, and I’m sure you’re right, at least in part. Another factor, however, might be that the pitch of the DX station is typically the same as the pitch of my sending sidetone, since I have the DX station centered in my passband -- which is usually set pretty tight. (I’m not one of those guys who likes to listen to weak, QSB-laden CW in a wide passband. It drives me nuts.) I could offset the DX station a few Hz by moving the IF shift to one side, which I’ll try. I also found this paragraph to be especially interesting: “ ... where the complaint was not hearing between bauds, the situation was remedied by changing the front end setting of "PRE" to "ATT" (yes on 160m, too), backing off the RF gain until the band noise was a tad less than moderate, and setting the AGC to slow. All of a sudden the QSK "sprang to life" ... It appears that QSK does not "sound right" when using fast AGC (my own impression as well) ... ” I totally get it about reducing the front-end gain of the receiver on most bands. However, with my current pathetic HF setup using a rather small wire antenna (I’m primarily a 6-meter op, which is where the big aluminum is for the time being), I’m really not troubled by too-strong signals, and the DX stations I hear are typically below my AGC threshold. That may all change in the near future, as I’m working on some new antenna ideas for my HF setup. But for now, I don’t really see why changing the AGC response speed should change anything. Nevertheless, I’ll try it. I do find, as have others, I guess, that using the QRQ mode at regular CW speeds makes detecting when the other station comes back much easier, subjectively. I now have a much better understanding of what had to be sacrificed to get that super-fast QRQ mode T-R switching, and why these trade-offs are unavoidable. For this and a number of other reasons, like being able to listen to the "up" DX pile-up in one ear, the KRX3 is going to be put higher up on my must-have list. Bill W5WVO ______________________________________________________________ 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
