I just bought an optical cable to connect my tv to my sound system. Never having dealt with or even seen optical cables before, I notice that there are small plastic looking caps on the ends of the cable. Are these to be removed before inserting them, or are these caps part of the cable and I shouldn’t mess around with them? If they are to be removed, are they simply pried off, twisted off, or what? Thanks, Dopers
A little skin oil from your fingers on an electrical connector is no big deal. Put a fingerprint on the end of your optical cable and it might not work at all. The cap is just there to prevent dirt or fingerprints and likely just pulls off.
This is also why the optical port is covered by a small cover that the connector pushes out of the way.
Yes. Uncap the connector end before plugging.
For the square-bodied optical plugs common on A/V equipment, the cap should just pull right out. Some optical connections use a round connection with twist-retaining lugs, so look to see if the dustcaps are retained or just pull off (I’ve seen both).
https://1cp3v31bcrm1lv5jv1crjrq1-wpengine.netdna-ssl.com/wp-content/uploads/2017/05/connectors.jpg
In the above diagram, all of the dust caps are pull-out to remove, even the round-barrel ST type one.
I always keep the caps on when the cables aren’t in use, and also keep the caps on the receiving end the fiber cables plug into. It’s not just finger oils and dust – you want to keep all dirt and contaminants out.
I’ve worked in cleanliness-obsessed places where you had to “repolish” the fiber ends every time you hooked them back up again. I don’t think that’s necessary for most common applications.
A bigger issue is broken fibers – be sure that you don’t bend the fiber through a tighter radius than it can handle, and be sure to handle the cables carefully when moving them, and don’t let the ends whip around, or let anything be placed on them. I’ve seen fiber bundles with several “dark patches” where some of the fibers were broken.
In fact, the reason I’m connecting these items is that I’m actually re-connecting them. The first time, I stupidly worked tirelessly at getting the cable bundled with two speaker cables and then banged on them to get them attached to the baseboard. Now they’re out of the way and useless, since I realized that in my zeal to have a nice, neat, unobtrusive set of cables, I damaged the optical cable beyond its ability to function. I’ll be waaaaaay more careful this time. Function over form.
With what are they polished? One of my friends in undergraduate school made fiber optic cables and said he just put the connectors on and polished them.
I was just coming here to say to be sure to save the protective caps, because it’s a good idea to keep the ends covered when the cable is not in use.
HDMI cables also usually come with protective caps to keep out dust and debris. I try to save those caps, too, for the same reason.
Here is a PDF
describing some wipes and cleaners (basically lint/debris-free micro fibres or similar material). Little bottles of isopropanol(?) are also available for use with wipes and tissues “to remove dirt and soil from optical fibers prior to termination and fiber optic splicing or to clean the end of connector ferrules”
We had a roll of one-use-only material that was like special emery paper that actually ground a tiny amount off the end. You used a little piece of it once, then advanced it to a fresh piece for the next time.
Thanks.
I saw someone splicing a whole bunch of those cables; before each splice they were definitely cleaned off with alcohol as well as neatly cut off, but I don’t recall any polishing of the cut ends (I assume a freshly cut end would be pretty clean, and in any case they got an extra dip into an alcohol bath). Unfortunately, I do not recall what was done with the ends that went into connectors, or if they had some short lengths with the connector terminals pre-attached.