Fred, K6DGW wrote: So ... running my K2 is like flying an F-16 or F-117A. I don't actually "control" the aircraft or radio, I "request" the computer to control it for me and hope it is listening?
------------------------------- Right, Fred, but notice that's what you did with your SX-28 too! You turned the dial to make a frequency mark line up with the indicator. That was "requesting" a frequency. The only thing you knew for certain was that it wasn't exact! The same is true of the K2. The difference is that the K2 is a lot closer than almost any analog system at any price. When you calibrated your SX-28, you were setting it so the requested frequency equaled the actual frequency as close as possible. But you knew that even at the reference frequencies you use to calibrate the receiver it wasn't exact. That's similar to the problem with the K2's inability to be absolutely exact to the Hz in establishing the exact tuning when you run CAL PLL even if the 4 MHz clock is exactly on so the frequency counter function (FCTR) in the K2 is "dead on", there's still the problem of deciding exactly what is "on frequency". In the K2 it's not a matter of reading a line on a frequency scale but instead is a matter of how accurately the DACs can read the tuning voltages being applied and record their value in memory. Then when you tuned in WWV later on your SX-28, there was the issue of deciding exactly when the frequency mark was aligned with the index. You can get very close, there's a limit to how "exact" you can be. That's like tuning in 10000.00 on your K2. The DACs then have to create the tuning voltage by the data in memory for that frequency, but there's a limit to how close they can replicate it, just as there's a limit to how close you can reposition the dial at 10000.000 MHz. The lines on the SX-28 dial have to have width so you can see them. There's a limit to how exactly you can position the pointer once the receiver is exactly tuned to the reference source, like WWV. The K2 has a tuning resolution of 10 Hz. That's like saying the K2's 'dial markers' are 10 Hz wide! And, finally, even if you did get the dial set exactly on 10000.000 Hz on your SX-28 and you had calibrated it with the same accuracy, you are still at the mercy of any drift in the oscillator frequency since you calibrated it! The same is true of the K2. It will change a little with temperature and time, although those oscillators are very stable! One thing the K2 can't match on your SX-28. Those human-friendly knobs, especially those honkin' big hand-wheels used for the main and bandspread tuning!! Sigh!! But then I don't need a fork lift to pick up my K2. People who groan when they hoist an Astron 35 amp power supply never carried an SX-28 around. Still, if I ever come across one that I can afford... Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
