[Elecraft] K2 Alignment and Test, Part II - No signal on TP3

[Don Wilhelm]

Cameron,

In order to calibrate the 4 MHz reference as stated, you must have a 
very accurate frequency counter (the first bullet), or you can listen 
with another calibrated receiver (2nd bullet), or you can just do as the 
3rd bullet indicates and set the C22 trimmer to center.  Whichever you 
use will not change the rest of your bringup of the K2.  When you have 
all bands working, I do encourage you to do a good dial frequency 
calibration - see my website www.w3fpr.com article for the procedure.

OK, now back to your problem.  I am not certain from your words, but I 
assume you read all zeros in the K2 display when you attempt CAL FCTR 
and the probe in TP3.  That may mean that the PLL reference oscillator 
is not working, or it could mean that your counter probe is not working.

If that is the case, try the probe in TP2 to see if you can read the BFO 
frequency.  If both TP2 and TP3 show all zeros, I would conclude that 
you have a faulty internal frequency probe or problems with Q9 and Q10 
on the Control Board.

If you have a good BFO frequency response at TP2, but all zeros at TP3, 
that means the PLL reference oscillator is not working.  Go to the 
schematic (RF Board sheet 1 of 4) and look in the upper left corner.  
The components shown there (over to but not including U4) are the ones 
you need to check for good soldering, and the diodes for proper 
orientation.  If you need help with diode orientation, look at the parts 
placement diagram in the back of the manual.  Then move on to the DC 
voltage measurements for Q19 to see if all looks well there.

You will need to get some reasonably proper frequency readout from TP3 
(The next and more important step is the PLL range which is the test in 
the right column).  That must be correct before moving on.

73,
Don W3FPR

On 7/3/2012 7:41 PM, Cameron Haines wrote:
> Correction.
>
>
> Hey Guys,
>
> Well, I am at the part where I need to test the 4 MHz oscillator calibration and ran into a snag. I am not getting anything on two different frequency counters when connected to TP3. Test up to this point have been good. Checked all the components around X1 and all look correct. No error message on startup.
>
> Any ideas where to go from here?
>
> Thanks,
> Cameron
> AE5UZ
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