[Elecraft] repost of K@ part II alignment and test problem

[James Caruthers]

I found the problem
It was RFC14.  Never did figure out what was wrong with it but things work 
after I rebuilt it.
----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at embarqmail.com>
To: "James Caruthers" <jcaruthe at maine.rr.com>
Cc: <elecraft at mailman.qth.net>
Sent: Friday, February 01, 2008 7:37 PM
Subject: Re: [Elecraft] repost of K@ part II alignment and test problem


> James,
>
> If you do not find a frequency at TP3 near 12100 kHz, and your probe is 
> good, then the PLL reference oscillator is not oscillating.
>
> Look at the schematic for the RF Board sheet 1 - all the associated 
> components are shown in the upper left corner to the left of U4.  At this 
> point, all are suspect - check and double (even triple) check the 
> soldering of each one.  Be certain D18, D16, D17 and Q19 are oriented 
> correctly (compare with the parts placement diagrams).
>
> Nnow that you have the BFO built,  do a better check on your counter probe 
> function - try the counter probe in TP2 and enter the menu for CAL FCTR - 
> you should see the BFO frequency (4912 to 4917 kHz).  If you find 
> something quite different than that frequency, then either the counter 
> probe or Q9/Q10 on the control board may have a problem.   The BFO signal 
> is weaker that the initial 4 MHz check and will show up problems with the 
> probe/counter input circuits more readily.
>
> 73,
> Don W3FPR
>
> James Caruthers wrote:
>> I am still having a problem getting by the part II tests.  I did find a 
>> problem with RFC15 and replaced it but I still have a problem when I run 
>> the cal fctr on tp3.  I get a rapidly changing reading which is now in 
>> the 1080 range.
>>
>> I checked d16, d17,c84, c85 and L31 per problem 235 on Appendix E page 8. 
>> The solders look good and item values are correct.
>>
>> I have rechecked solders on all boards and things look good
>>  Rechecked the probe per the Part I tests page 47 and get a good value of 
>> 3999.98
>>
>> Does anyone have a suggestion as to what else I should check to try and 
>> find the problem
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