[Elecraft] K3S Receiver Spurious

[David Gilbert]

Is your K3S connected to a computer (or some other significant piece of 
electronics), and if so, are they tightly and closely bonded together 
chassis wise?

73,
Dave   AB7E



On 12/3/2023 8:11 PM, Michael Tope wrote:
> Hi All,
>
> I noticed when operating the ARRL 160 contest this weekend that my K3S 
> has developed a nasty case of what appears to be some sort of LO 
> spurious. When tuning across strong signals, I can now hear a 
> low-level buzz (like phase noise reciprocal mixing) as I tune off them 
> followed by a distinct tone peak 400 Hz off the fundamental frequency 
> (as if there is a discrete spurious at that offset from the carrier 
> frequency). I had noticed that a few days or weeks ago on one signal 
> and dismissed it as being someone with a dirty transmit signal. After 
> tuning across a number of strong signals on 160 and seeing the same 
> phenomenon, it is clear that the problem is coming from my rig.
>
> I don't know if the problem is showing up on my transmit signal as I 
> haven't received any reports that I have a dirty transmit signal. I 
> just listened to my carrier on a WebSDR and it sounds clean and I 
> don't see any sidebands on the waterfall, so I think it may be 
> confined to receive only.
>
> So far I have been troubleshooting this remotely over the internet, so 
> I haven't had a chance to twist knobs or look at the hidden menus 
> carefully. Any ideas as to what might be causing this? Is there some 
> problem common to the K3S that manifests itself like this?
>
> Thanks & 73,
>
> Mike W4EF...................