Friday, June 19, 2009

CW like butter

This is what I have been contending with as far as activity. This is a shot of the 40M centered around 7016. Virtually NO signals. Of course when there are no signals you start to think of other things to do.

Recently in the development channel of PowerSDR there has been a lot of work on CW performance. I decided to give the radio a performance check since I had the latest version of the "test" branch open on the F5K. I set the delay to minimum and I had the panadapter set to 96k since I had recently been playing with the wide band image rejection and that is the correct bandwidth for running the automatic calibration and initialization for that mode. For the algorithm to set up correctly it needs an initial value to set up off of. I usually run at 48K bandwidth because you get filters that are a tiny bit sharper. That is the advantage of 48K With the higher bandwidths on the other hand you get significant reduction in "lag". This "lag" problem is nothing like the "lag" of yester year in the SDR-1000 days. The processes in the radio have attained enough efficiency that lag at any bandwidth has not been a consideration for a long time in my opinion.

In CW there has always been a switching artifact at very high speed. When you go from TX to RX in a QSK setting there would be occasional annoying pops. Today at 96K at minimum delay (10ms) running 60 wpm there were virtually NO pops. The QSK was as butter smooth as any Ten Tec I ever owned. I have had Ten Tec's for years. The most responsive CW rig was the 580D. It had the famous TT audio derived AGC and I swear that radio could go 120wpm and not bat an eye. This morning the smoothness of my F5K rivaled my memory of my trusty old 580D. I used a AL-1500 with that radio and the QSK switching board. Since that time I sold the AL-1500 and bought a Acom 2000A. The Acom is all facny but it is not as good a CW amp as the old AL 1500 with the QSK board. Since that time I have switched my CW habits to semi break in so things don't sound like machine guns when I transmit. The new level of CW smoothness I believe to rival my old set up.

I do have an external electronic QSK switch in the line with my AL-80B amp and given how well this works I'm going to give that a go tonight and see how it plays

Like the logo says "things just keep getting better and better"