[Elecraft] Using dual watch with RX SHFT=8kHz

[Wayne Burdick]

Yes. Future.

Wayne

On Sep 24, 2014, at 2:08 PM, Matt VK2RQ <matt.vk2rq at gmail.com> wrote:

> A long long time ago on another mail list there was a discussion about why it was not possible to use dual watch together with the RX SHFT set to an 8kHz shift. If this would be implemented in a straightforward way, such a shift would result in an asymmetry in range of frequencies your second VFO could cover above and below the first VFO (eg. ADC covers LO+/-15kHz, VFO_A is LO+8kHz, so VFO_B can range from VFO_A-23kHz to VFO_A+7kHz.
> 
> However, if you tried to set VFO_B to greater than VFO_A+7kHz, one possibility would be for the KX3 to change the shift from LO+8KHz to LO-8kHz. This would then permit coverage from VFO_A-7khz to VFO_A+23kHz. Everything would seem to be on the opposite sideband, so the demodulation code would need to compensate.
> 
> By combining these two modes of operation, the dual watch could be extended so VFO_B has a ranges of VFO_A +/-23kHz. If you used a greater IF shift than 8kHz, say 11kHz for example, then this could extend the range even further, say +/-26kHz.
> 
> Regardless whether such such extended coverage is implemented for dual watch, the PX3 would need to behave sensibly when using of dual watch with IF shift.
> 
> 73,
> Matt VK2RQ