My primary complaint with the F-type connector is that it only does half the job: a proper connector should make a reliable and consistent mechanical and electrical coupling. For the latter, the F-type fails miserably, on account of having no protruding pin of its own: reusing the center conductor as a “pin” is at best slapdash, and at worst fails to account for inconsistent conductor cross-sections.
When affixing an F-type connector onto a new segment of coax, unless great care has been taken to slice the cable cleanly, the center conductor often ends up with a arrow-shaped tip which also flattens the round cross-section into an oval. This tip is now a minor danger to people, in addition to no longer being assumed as round. This certainly doesn’t help with reliable mating later.
Furthermore, a solid copper tip is not ideal for a connector, unless the opposite coupler that grasps the tip is made of copper as well. But copper can’t be used to make springy receivers, so inevitably another metal must be used. But the prevailing composition of contacts for connectors are either solid brass or are plated (eg gold). But a sharp copper tip will end up scratching the mating surfaces over time.
And this is just the start of the F-type’s follies. The user experience of turning a 7/16" fine thread in narrow spaces is exhausting. With no consistent specs for the F-type, some cheaper connectors have the thinnest possible hex head to fit a wrench on. Compression F-type is better, but then we have to compare to other connectors.
In the broadcast and laboratory spaces, BNC is the go-to connector, with easy mating and quarter-turn engagement. It also comes in 50 and 75 Ohm variants (albeit confusingly). In telecoms, the SMA connector is used for its small size, and larger coax might use the beefy N connector. Some of these variants are even waterproof. Solderless is an option. All these connectors are rated by their manufacturers for a minimum number of mating events.
In all circumstances, according to this chart, the RF performance of BNC, SMA, and N are superior to F-type, which has only ever been used for TV, CCTV, and certain low-frequency clocking systems. I’m not sure what you mean by “rated to absurd frequencies”, but surely SMA’s (up to) 25 GHz rating would be tremendously and wildly insane by comparison to 1-2 GHz for F-type.
So that’s my beef. It’s just a bad connector, used only because it’s cheap.
sxan@midwest.social 2 days ago
In not the person you replied to, and I can’t speak about the engineering merits; but as a user I hate F-type connectors. They’re bad enough when you have to only install them once in the lifetime of the connected device - it’s the threaded screw that’s the worst, I think, for which no non-technical user owns a tool beyond their fingers, from which the bevel invariably strips the flesh; although I’ve also bent enough of those pins trying to get something connected in an awkward place, or because I was tired, or being sloppy. It’s not a connector that’s convenient for amateurs, and most of its users were and are amateurs.
As a connector for multiple, frequent dis- and re-connection, it’s an utter disaster. Sure, that’s not what it’s designed for. It was designed to be a semi-permanent extension of permanent wiring, and I’m sure it’s great at that.
The context of the whole thread, though, was end-user, repeated, frequent connections for people who have to be reminded by a manual that the thing needs to be plugged in. Coax is horrible for that.
skillissuer@discuss.tchncs.de 2 days ago
so you want BNC
sxan@midwest.social 2 days ago
BNC is better, but I’ve only encountered it, like, twice.
Honestly, I’ve never been happier since USB-C took over. I compare today to the early 90s and having 8-12 different connectors - two of which looked identical but were incompatible - to hook up a single Sun workstation. I clearly remember dreaming of a day when there would be a single connector for everything, and we’re really close. Higher wattage demands and video connectors (HDMI, DP, DVI) are the only hold-outs - and I’m not sure why USB-C hasn’t conquered video yet, unless it’s a cost thing, because it’s certainly capable.
skillissuer@discuss.tchncs.de 1 day ago
you don’t see BNC as often because it’s more expensive, bulkier, requires different crimping tool and has a separate pin. but if you need to connect and disconnect things often and quickly, then it’s a good connector. i bet you’ve seen (RP-)SMA a lot instead, but this one is also more expensive than F, has separate pin and is too small to easily make a connector for common 75 ohm cables. reducing diameter would mean higher loss
aesthelete@lemmy.world 2 days ago
USB-C likely will take over video eventually. I use it for video on two out of three of my monitors and the Nintendo switch can be used that way.