[Elecraft] Mysterious K3 Symptoms - RFI?

[Pete Smith N4ZR]

Thanks!  I have a type 31 toroid on the Ethernet cable at the shack end, 
with 11 turns of the unshielded Ethernet cable wound on it.

73, Pete N4ZR

On 3/13/2024 10:43 AM, Bayard Coolidge, N1HO wrote:
> Although I don't have an amp, and ran my K3 barefoot, and run my K4D 
> barefoot as well, I do have a 100 foot CAT5E cable running into the 
> shack from the other end of the house, through the attic (there being 
> no basement here in south Florida!). Initially, I was seeing a fair 
> amount of noise from it, and was able to quench it by winding a couple 
> of turns around a small clamp-on choke.
>
> That doesn't seem to affect the network performance, so I can reliably 
> run it at 400MBit/second, and it seems to clean up whatever other 
> noise it's picking up from nearby homes (most are on small lots of 
> about 1/5 acre) and the condominium complex next door. I still have 
> some strange noise from other sources coming in from the antenna, and 
> the HVAC's air handler is very noisy, particularly on 30m through 15m, 
> but I know it's not the twisted-pair Ethernet line. My CAT5E cable 
> plugs into a small AC-powered router, and feeds my Mac, the K4D, as 
> well as a laptop occasionally.
>
> HTH, and 73,
>
> Brandy, N1HO (EL96xh)
>
>
> On Wednesday, March 13, 2024 at 10:22:02 AM EDT, Pete Smith N4ZR 
> <pete.n4zr at gmail.com> wrote:
>
>
>
> One culprit I can think of is a 100-foot Ethernet cable between my
> station and my FIOS router.  I have bought a shielded replacement but
> have not yet installed it.  After reading some of the recent commentary
> about so-called "shielded" cables, I'm wondering if this is worth doing.
>
> Any suggestions, either K-3-specific or more general, would be much
> appreciated.
>