[Elecraft] Fw: Re: K2: "Pop" when switching certain bands

[Don Wilhelm]

Jim,

You might want to check the PLL Reference Oscillator Range on that K2 - 
sometimes called the "R30 voltage".

Don W3FPR

On 7/3/2019 5:24 PM, Jim KO5V wrote:
> Don,
>
> Setting each VFO to a frequency within the 15M band cured the "VFO B-A" pop. I checked the other bands, and found 20M "popping" when changing VFOs. One was set to 14.223, the other to 14.342. I found a pop as I tuned through ~14.348, so setting that VFO to a frequency lower that that, cured it. Does the rig effectively tune through the frequencies between the VFOs as it is switched, so if there are pops, it might see them?
>
> I still hear pops that are louder than I like as I tune from 15M to 12M, and 17M. When going from each of those bands into 15, it is more of a click - like between 20M and 10M. I guess I can live with that.
>
> Thanks again for your patience. and for sharing your experience.
>
> 73, Jim KO5V
>
>
> -----Original Message-----
>> From: Don Wilhelm <donwilh at embarqmail.com>
>> Sent: Jul 3, 2019 4:49 PM
>> To: Jim KO5V <ko5v at earthlink.net>, Elecraft List <elecraft at mailman.qth.net>
>> Subject: Re: Fw: Re: K2: "Pop" when switching certain bands
>>
>> Jim,
>>
>> There is no relay action when changing from VFO A to B or the other way
>> around - the MCU just sends different data to the PLL and PLL Reference
>> Oscillator.
>>
>> However, 20 MHz may be on the lower limit of the available VFO tuning
>> range for 15 meters.
>> Try tuning the VFO for both A and B back into the 15 meter band limits.
>>