If anyone remembers my thread a few months ago about my Ethernet run from my den to the living room, I have an update.
Here's the background for those that didn't read it: The ethernet cable runs through the attic, underneath my inverted V dipole and Cushcraft R6000, which are on the roof. On 14.210-14.111 Mhz, I was getting horrible tone warbling...probably as high as S7-S9. I figured out that it was being generated by the equipment in the living room, so I tried filtering it by wrapping the TX/RX wires around ferrite torroids. Unfortunately, when that didn't work using ceramic disk capacitors to get rid of it from the TX pair also killed the ethernet. So bypass capacitors weren't a viable solution.
I managed to get a spool of shielded CAT5E cable from someone at work a few weeks ago for free. So yesterday, I set out to pull that as a replacement to the standard CAT5 cable. This shielded cable included an additional ground braid, as well. After running the cable, I attached a piece of 14ga braided wire to each side of the cables ground braid and stuck it into an available ground plug at each end.
I'm happy to report that using this cable and grounding technique has reduced the tone on 14Mhz to barely audible above the noise level. The notch filter in the rig is easily able to kill it now. I found an article on the internet that states that shielded CAT5 can reduce the "antenna effect" of ethernet by as much as -20db, and if you ground the additional braid by as much as -40db. I believe it now.
BTW, this cable isn't cheap; I was lucky to get it for free. Unfortunately the devices that I'm connecting (Xbox 360 and DirecTV DVR) don't really perform well using wireless networks. If you're in the same situation as me, use the shielded cable...it works.
Here's the background for those that didn't read it: The ethernet cable runs through the attic, underneath my inverted V dipole and Cushcraft R6000, which are on the roof. On 14.210-14.111 Mhz, I was getting horrible tone warbling...probably as high as S7-S9. I figured out that it was being generated by the equipment in the living room, so I tried filtering it by wrapping the TX/RX wires around ferrite torroids. Unfortunately, when that didn't work using ceramic disk capacitors to get rid of it from the TX pair also killed the ethernet. So bypass capacitors weren't a viable solution.
I managed to get a spool of shielded CAT5E cable from someone at work a few weeks ago for free. So yesterday, I set out to pull that as a replacement to the standard CAT5 cable. This shielded cable included an additional ground braid, as well. After running the cable, I attached a piece of 14ga braided wire to each side of the cables ground braid and stuck it into an available ground plug at each end.
I'm happy to report that using this cable and grounding technique has reduced the tone on 14Mhz to barely audible above the noise level. The notch filter in the rig is easily able to kill it now. I found an article on the internet that states that shielded CAT5 can reduce the "antenna effect" of ethernet by as much as -20db, and if you ground the additional braid by as much as -40db. I believe it now.
BTW, this cable isn't cheap; I was lucky to get it for free. Unfortunately the devices that I'm connecting (Xbox 360 and DirecTV DVR) don't really perform well using wireless networks. If you're in the same situation as me, use the shielded cable...it works.