[Elecraft] K3: Are the birdies really birdies

[Kok Chen]

On Nov 16, 2010, at 3:02 PM, Mike K2MK wrote:

> Moving the shack CAT 5 cable away from other radio related cables is having a positive effect. Next I'm going to try a shielded CAT 5 cable from the wall to the shack PC.

I can attest to the effectiveness of shielded Ethernet cables (for me anyway).

After fighting with Ethernet noise, I finally swapped out all the Ethernet switches in the house with ones that have metal enclosures (Netgear GS series), and replaced all UTP CAT-5 cables to STP CAT-6 cables.  The shielded switches by themselves didn't do much until I went to the STP cables.

I couldn't find shielded CAT-5 at the local Fry's and just went with CAT-6.   

I believe the critical difference is STP (shielded twisted pair) vs UTP (unshielded) and not the difference of going from CAT-5 to CAT-6.  If you can't find shielded Ethernet switches, perhaps at least look for ones where the RJ-45 jack has the metal tab that connects to the shield of the STP CAT cable.

I still have a box full of unshielded CAT-5 cables that I have been using for controlling remote antenna switches and such :-).

Going to WiFi can also help, but some WiFi routers, like the early Apple Airport Express, are themselves very RF noisy in the HF region.  I don't know if the newer AirPort Express are any better since I had banned the Apple AirPort Express from this QTH :-).

73
Chen, W7AY