[Elecraft] K2 alignment part 2 question

[Don Wilhelm]

  Ron,

Yes, the frequency should not revert to the high reading - it should stay.
Check the soldering at RF Board U5 carefully for solder bridges and also 
J8 pins 15 and 16.  Then on the control board check U6 pins 19 and 20 as 
well as J8 pins 15 and 16.  Make certain all those points are well 
soldered.  If there is excess solder, wick it away and re-flow the 
solder with a hot soldering iron (750 degF or higher)

What I suspect is happening is that the DAC2CS digital signal is going 
low at times it should not because it is shorted to another digital line.

If you find nothing in those areas, ask again and I will give you some 
other checks that you can do in the analog realm.

73,
Don W3FPR

On 7/8/2011 12:39 AM, R Thompson wrote:
>       I'm doing the alignment at the end of part 2 of the assembly.  So
> far all seems to be well.  There is a quirky little thing that I wanted
> to ask about.
>
>       From page 63, PLL Reference Oscillator Range Test, step 3.
>
> "When you're in frequency counter mode, the BAND+ and BAND- switches can
> be used to check the range of the PLL reference oscillator.  First, tap
> BAND+ and write down the frequency reading below (typically about 12100
> KHz).  Then tap BAND- and write down this frequency reading (typically
> 12080-12090 KHz)."
>
>       The range is fine, 13.25 KHz, but I noticed that when I tapped the
> BAND- switch that the Ref. Low Freq. was only displayed for a short
> time, from a fraction of a second to a couple of seconds, and then the
> screen went back to the Ref. High Freq..  I was expecting the Ref. Low
> Freq. to stay displayed until BAND+ was tapped again, as it does for the
> BFO Test on page 65.
>
>       Is this normal behaviour for this test?  If not, is it anything to
> be concerned about?
>
>       Thanks,
>
>                 Ron VE8RT
>
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