Why Ferrite Cores?

[Takumi]

What's the difference between these two?

http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10231&cs_id=1023102&p_id=2218&seq=1&format=3#specification

http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10231&cs_id=1023104&p_id=2404&seq=1&format=3#specification

 

[Doug_G]

Ferrite cores are used to prevent high frequency noise from going down the cables. Usually that sort of thing is added if the device they are connected to generates noise above the level permitted by government regulations. That is to prevent stray noise from causing interference with radios, etc. It is probably not that important.

What IS more important is the wire gauge. The more expensive one has larger 24 AWG, versus 28 AWG on the cheap one. 24 AWG will have lower signal loss. That might not matter on a mere 6' cable... but then again, the good one isn't exactly expensive.

 

[doug]

hmmm... Over only 6ft, I'd probably go with the cable with the ferrite cores myself. These are digital signals, it's kind of an all or none sort of thing. Unlike analog, signal loss isn't much of an issue once you're above threshold. The ferrite cores might help protect against transients like a compressor kicking on (e.g. the fridge or AC). Not that I'd really expect that to be an issue, either.

Here's an extreme example. I had a network (i.e. digital) set up in a tunnel about 20 meters from a 200 kV power supply that would occasionally arc, i.e. shoot lightning bolts. Even though that supply was on the other side of a Faraday cage, the noise from the arcs would knock out the network. Putting ferrite beads on each of the Cat-5 cables solved the problem for the most part.

 

[TEG]

http://en.m.wikipedia.org/wiki/Ferrite_bead

http://www.avsforum.com/avs-vb/archive/index.php/t-854730.html

 

[Takumi]

Thanks guys!