+++++++++++++++++++ Date: Wed, 16 Jan 2002 09:22:06 -0800 From: Vic Rosenthal Organization: Transparent Software To: elecraft at mailman.qth.net Subject: Re: [Elecraft] QSK... Tom Hammond NØSS wrote: > > If properly implemented, QSK can be a SIGNIFICANT benefit to CW operators I think QSK has really gotten a bad name from the poor implementation thereof found in many of the popular (Japanese) transceivers. For example, my TS850s has very fast QSK, but it is quite clicky and hard on the ears, especially if the RF gain is not reduced. The 850 is relatively good; some of the others are worse! Nevertheless, I suffered with it a lot in pile-ups, because otherwise you will miss many opportunities to call the DX station. Years ago I operated in traffic nets, and there too it was a necessity. It is true that for ragchewing, semi-QSK is adequate. The K2 implementation is not quite as fast as the 850's, but (partly as a result of this), it is very quiet and smooth. It is possible to increase the speed without introducing noise by adjusting the value of R17 on the control board; I put 1 MB in parallel with my R17 for a significant improvement. 73, Vic, K2VCO Fresno CA +++++++++++++++++++ Date: Tue, 20 May 2003 17:22:35 -0500 (EST) From: Dave Gingrich K9DC To: Don Rasmussen Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] K2 Fast QSK On Tue, 20 May 2003, Don Rasmussen wrote: > Hi Guys, > > The K2 QSK seems to work up until 16 WPM with K2 > #3312. That is the highest speed where the receiver > does not mute in between dashes when sending the > number zero. I'd like to improve on this. > > Gary S. suggested: > > You can try shortening the t-r delay muting by > reducing R17 in the Q6, Q7 mute circuit from 3.3M to > something smaller. Try tacking another resistor of > 3.3M across the existing R17 for example. If the delay > becomes too short, then you'll hear too much of a t-r > transition "pop" and you'll have to use a larger > value. Use a 0.00 t-r setting. > > Has anyone else tried this, and come up with an > optimal value that I might use as a starting point? I tried reducing it to 470k, but it popped rather severly. I did not have an 820k so I ended up using 1 meg. Significant improvement in speed. -Dave K9DC ++++++++++++++++ Date: Tue, 20 May 2003 15:45:46 -0700 From: Vic Rosenthal Organization: Transparent Software To: Don Rasmussen Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] K2 Fast QSK Don Rasmussen wrote: > You can try shortening the t-r delay muting by > reducing R17 in the Q6, Q7 mute circuit from 3.3M to > something smaller. Try tacking another resistor of > 3.3M across the existing R17 for example. > Has anyone else tried this, and come up with an > optimal value that I might use as a starting point? I have been using a 1 M resistor across the existing 3.3 M resistor. Any smaller value DEFINITELY causes a click. I think this is probably about as aggressive as you want to get. It does speed up the QSK, although I haven't tried to determine by how much. 73 Vic K2VCO +++++++++++++++++