That's normal because of the way the dial works. In normal operation the dial readout is not directly related to the VFO frequency. It's what the logic *assumes* would be the frequency, assuming the local oscillator can tune to it. There's no direct measurement of the local oscillator. The local oscillator frequency is only measured in CAL PLL.
When you run the CAL PLL, you look up the internal counter to the L.O. output and the K2 logic measures the frequency of the L.O. at various tuning voltage levels. It then creates a "table" of values that says "If a tuning voltage of 'x' volts is applied to the L.O. tuning, then the receiver ought to be tuned to 'y' kHz." And it's that 'y' kHz frequency that is shown on your dial in normal operation. Think of it as an old analog dial with numbers written on the face so you can see what frequency it's tuned to by seeing where the pointer is on the dial. Running CAL PLL tunes the K2 across the tuning range and "writes" numbers on the dial at intervals so you can see what frequency you are tuned into when you are operating. Unlike the old analog dial, there's no "hard stop" at each end of the range saying that you can't go farther. It'll just let you keep tuning and tuning and tuning. So, if you tune outside the L.O. range, the numbers will continue to change on the dial, even though the local oscillator can't be tuned to that frequency. Ron AC7AC ----- Original Message ----- I'm the builder of #4175 and have a question concerning the lower end of the spectrum. I was attempting to listen for the VFO of the 2N22-40+ that I'm building at 2085-2185mhz. I don't hear the VFO nor do I hear anything else down there. I tuned into the AM broadcast band and couldn't hear a single station. Is this normal for the K2 or do I have a problem? _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
