[Elecraft] K2 Alignment & Test Part II

[Neil Zampella]

Don,

I installed the 12pF cap as suggested didn't help, so I'm going to
request a replacement Q19.

Thanks,

Neil, KN3ILZ

On 12/25/2019 3:24 PM, Neil Zampella wrote:
> Don,
>
> Thanks, I'll work on that tomorrow and let you know how it goes.
>
> Merry Christmas!!
>
> Neil
>
> On 12/25/2019 11:19 AM, Don Wilhelm wrote:
>> Neil,
>>
>> Your readings on the PLL range test show that Q19 is marginal. Q19 is
>> not oscillating properly at the high end of the PLL range.
>>
>> The first thing to try is a small capacitor (12 to 15pF) from the
>> source of Q19 to ground.  You can easily mount the capacitor between
>> pins 1 and 12 of U4.  You can use one of the capacitors from the K2
>> kit and request a replacement from support at elecraft.com
>>
>> If that does not allow proper frequencies for the PLL Range Test,
>> then get a replacement Q19 from parts at elecraft.com.
>>
>> Merry Christmas everyone.
>>
>> 73,
>> Don W3FPR
>>
>> On 12/24/2019 6:19 PM, Neil Zampella wrote:
>>> Hi,
>>>
>>> Started to do the Align/Test Pt II, and properly saw the correct
>>> frequency of 12090 +/- 30 kHz.   Tried the next part to adjust the
>>> Reference Oscillator using my other K2 as the receiver and was able to
>>> hear the oscillator at 3999, but C22 would not adjust to a
>>> zero-beat.     OK ... so it was close for the time being, so I figured
>>> I'd use my KX3 to verify it later.  Moved on to the range test.   The
>>> Band- and Band+ buttons did not affect the display.
>>>
>>> Dug into the list archives, and saw a number of messages from Don to
>>> check the solder joints, alignment, and type of D16, D17, R19, and
>>> L31.    I realized that somehow I missed installing R19.   So I
>>> installed the resistor, then restarted the alignment.   This time
>>> when I
>>> switched to CAL FCTR, the rig did not display the expected frequency of
>>> 12090, but  a frequency of 3560 or so, flickering between readings.
>>> However, when I pressed the Band- button, it changed to a steady 12084,
>>> but when the Band+ was pressed, back to the 3560 flickering.
>>>
>>