[Elecraft] [K3] funcube on K3 IF output

[Alan Bloom]

On 07/06/2016 11:22 AM, Joe Subich, W4TV wrote:
>
>> Is there anyway to prevent the frequency changing when tuning on the
>> K3 VFO? I noted this is possible when using a P3, does this use
>> software built into the P3 or does it send commands back to the K3?
>
> It uses capabilities built into the P3.  Specifically, in "fix tune"
> mode, the P3 changes its center frequency to compensate for changes
> in the K3 VFO frequency.
>
> With the SDR software that implemented a fix tune mode, the FCD+ could
> do the same thing.  *However* the SDR software would need to know the
> the K3's VFO A frequency, mode and IF Offset (IF; and IS; commands),
> calculate the IF frequency that corresponded to the desired "fixed
> frequency" *and* compensate every time the K3 VFO, mode and/or filter
> shift/width changed.

*and* compensate in real time for the latency of the communications 
between the P3 and K3.  It was a major development effort to get it to 
work smoothly.

Alan N1AL



> 73,
>
>    ... Joe, W4TV
>
>
> On 7/6/2016 11:36 AM, graham.wood1 at mypostoffice.co.uk wrote:
>> Hi All
>>
>> I have been trying the Funcube PRO + dongle connected to the IF
>> output on the K3. It works fine, displaying sigs in a 180khz passband
>> centered on 8215  EG setting the FCD to 8215 khz & tuning the K3 to
>> 10100 (A RTTY WX stn) this stn is still visible on the FCD display
>> with the K3 is tuned to 10180 khz. Is there anyway to prevent the
>> frequency changing when tuning on the K3 VFO? I noted this is
>> possible when using a P3, does this use software built into the P3 or
>> does it send commands back to the K3?
>>
>> Gray G3VIP
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