HDMI cable ferrite EMI filters - Page 1
Forum section: electronics / general

author: wilfred
author_rank: Super Contributor
timestamp: June 28, 2012, 06:34:41 am
content: /.

author: T4P
author_rank: Super Contributor
timestamp: June 28, 2012, 07:24:55 am
content: Magnet ...

author: nitro2k01
author_rank: Frequent Contributor
timestamp: June 28, 2012, 07:37:26 am
content: Quote from: DaveXRQ on June 28, 2012, 07:24:55 amBut then he has to figure out how the f***ing things work... (That was joke. If you get it, you do.)I've seen two types of these EMI filters, either a one piece block with a hole, or two pieces. Logically, if the device has a clip on type plastic case, it's probably a two piece type. If the plastic case is molded, it's probably a one piece type, since there's no point in opening it anyway. In that case, you can't remove the ferrite bead without cutting the cable anyway, since the plug will be in the way.

author: G7PSK
author_rank: Super Contributor
timestamp: June 28, 2012, 09:11:57 am
content: I doubt that they are fake I have cables like that where the plastic is molded around the ferrite tube. You can remove them if you want without cutting the cable, cut of the plastic to reveal the ferrite tube which you then hit with a hammer in order to break it.

author: free_electron
author_rank: Super Contributor
timestamp: June 28, 2012, 12:39:02 pm
content: Doesnt do anything for hdmi... Hdmi is a differential pair carrying a digital datastream. Hard to corrupt...Vga os analog and is not differential. There it does work.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: June 28, 2012, 03:47:01 pm
content: Quote from: G7PSK on June 28, 2012, 09:11:57 amAh, of course. You can remove anything with a hammer, or a hacksaw, or some TNT. What I really meant was that there's no way of removing it without destroying the cable, or the bead itself.

author: SeanB
author_rank: Super Contributor
timestamp: June 28, 2012, 03:57:44 pm
content: Most of the time these are there to pass EMC for radiated emissions, that the signal is differential or not is moot, the ferrite is because the cable is a long wire antenna. These were probably overruns for a product that actually went for EMC testing and failed initially but passed with the ferrite on the leads.

author: Michael L. Rappaport
author_rank: Newbie
timestamp: August 07, 2016, 06:49:04 am
content: The metal part of the connector broke off on an HDMI cable very similar to the one shown in the photos, i.e., with rubber "EMI filters" on both ends and plastic braided shielding. The fact that the "filter" was molded rubber was already suspicious since ferrite filters normally have plastic housings that can be snapped onto the cable.Having nothing to lose, I sliced the "filter" in half with a disk on a Dremel-like tool and removed it from the cable. It was solid rubber: no ferrite, no wire inside...just solid rubber. I tried to measure its resistance, thinking that it might be loaded with graphite. My DVM showed over-range on the highest resistance scale. This "filter" is a fake. To be honest, before the connector broke, the cable performed fine connecting a Blu-ray player to a high-definition television. Nevertheless, I consider this deceit, which I would never reward with another purchase from the same supplier.

author: Halcyon
author_rank: Unknown
timestamp: August 07, 2016, 07:08:51 am
content: Moulded types are far more common than the "clip on" types. That said, it's doing nothing for your HDMI signal, so don't be too fussed.