[Elecraft] Fw: Re[2]: PLL Range test

[Dave Van Wallaghen]

GM James,

I think you will be fine with a 15.4KHz range. The problem when approaching ranges much greater than that is that although the K2 firmware will linearize the VFO adequately, the granularity of fine increments may start to suffer, and it'll be more susceptible to temperature change.

If you like to experiment and have enough #26 red enamel wire left, you might try taking off another turn and see what the range is. If not, then I think you will be just fine with your range.

BTW - I did all the testing for this change and used a set of cores to perform multiple tests. I saw these variances as well from the same batch of cores. The mix varies some between cores and produces different inductances with the 15 turns of #26 wire. Some I had to take a turn off and some were fine. I had one that produces a 18KHz range. Pulling a turn returned it to around 15KHz.

73,
Dave, W8FGU


On 11/5/2021 8:27:26 AM, "JAMES GUNNOE" <gunnoe at comcast.net> wrote:

>To follow up on my question about the PLL range test, how critical is it to be at or below 15Khz? Currently I am at 15.40Khz after playing around with the winding spread. The errata sheet says to be between 9.98Khz and 15Khz difference in the high and low reading.
>
>73
>James, KJ4KEM
>
>
>>  On 11/04/2021 7:57 PM Comcast <gunnoe at comcast.net> wrote:
>>
>>
>>  Hello again,
>>  Still building a K2. I got to the PLL reference oscillator range test and did have to remove one turn from the toroid.My range at first was 20.6 Khz.
>>  I got it down to 15.38Khz. I am worried if I remove another turn it will be too low. I went ahead with the continued testing and all the numbers (test results) are good.
>>  I stopped for the night on the BFO alignment.
>>  My questions is, is the 15.38Khz ok or do I need to remove another turn from the toroid?
>>
>>  73
>>
>>  James, KJ4KEM
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