[Elecraft] [K3] Odd freq shift in diversity mode after VFO upgrade

[Don Wilhelm]

Rick,

Something on that order is to be expected when you are using different 
filters in the main and in the sub.  The filter centers do not match, 
and that leads to calculations of the filter centers which are different 
- the result is that the K3 is 'confused' and the offset is the result.
Use the same filters in both the main and the sub when using diversity.

73,
Don W3FPR

On 7/12/2015 10:13 AM, rick.ag6ay at gmail.com wrote:
> post starts now ...
>
> I can better explain and reproduce the issue now.  Thanks to Dale  WA8SRA,
> Don W3FPR , and Wayne N6KR for hints along the way
>
> I have the following 8-pole filters
> Main: 1=15k, 2=6k,  3=2.8k, 4=2.1k, 5=0.4k
> Sub: 1=0.0, 2=0.0, 3=2.8k, 4=2.1k, 5=0.4k
>
> I am tuned to 10.000 MHz USB in diversity mode with Lo = 0.00 and Hi = 3.0
>
> I observe RX A XFIL = FL2 (6 kHz) and using BSET I see that RX B XFIL = FL3
> (2.8 kHz)
>
> At this time RX A passband starts at 10.000 MHz but RX B passband is shifted
> -1.5 kHz to start at 9.9985 MHz
>
> Now I decrease Hi to 2.8 kHz.
>
> The instant I do this, RX A XFIL shifts from FL2 (6 kHz) to FL3 (2.8 kHz)
> and RX A and RX B passband are both aligned properly to start at 10.000 MHz
>