[Elecraft] PLL Reference Oscillator Range Solved

[Ed Palmer]

Good evening all.

 Just an update on K2 #4595 regarding the PLL reference oscillator range problem I was experiencing. I contacted Gary at Elecraft via e-mail a few days before the holiday. 

Gary suggested that perhaps the crystal X1 in the PLL was the culprit. I received in the mail today a different crystal along with a 12 mH inductor and new diodes for D16 and D17. I replaced the crystal only and it by itself brought the PLL reference oscillator range up to 10Khz from the previous 8 Khz. Should I even bother with the different inductor?  I also believe the diodes are probably doing the job as well.

Now to find out why the BFO range is too low. The BFO high frequency comes in above the expected minimum of >=4916.3 at 4918.2 The BFO low frequency comes in above the expected maximum of <=4912.7 at 4914.8 with a resulting range of 3.4 compared to the expected minimum range of >=3.6. D37 and D38 are of correct values as are X3 and X4. 

Building this K2 this last couple of weeks has been shall I say, an enlightening if not humbling experience. It's time for bed.

73, Ed N0EHQ