[Elecraft] K2 Alignment & Test Part II

[Neil Zampella]

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.
>>
>