So... how many of you still know what these objects are? Have you ever used them? 😂

@TheGibson @fribbledom don't think they're baluns...
the one on the left is a simple tee, the one in the middle is a 50Ω termination. unlike the other two, we didn't run across the one on the right in our everyday work at university, but we suspect it's a simple tee as well.
we didn't really think of BNC fittings as being "old".... they're still far and away the most common connector used in physics equipment.

@diodelass @fribbledom

My bad... I always called them baluns... what I was taught...

they are old for general networking purposes... I still see them in use in manufacturing zones at clients ocassionally.

@TheGibson @fribbledom true enough, it's been a good minute since ethernet went over BNC, and it seems like antennas are generally not that these days either (threaded connectors have better passband)

@thegibson a balun is a sort of transformer used to go from a balanced to an unbalanced line. For example going from window wire or ladder line to coax. @fribbledom @diodelass

@dude @fribbledom @diodelass

Well, then, that probably explains those other Baluns that are used to adapt Twinax to Cat5 and back.

@thegibson I'm not familiar with that type but it looks like the same concept. We use baln's a lot in radio @diodelass @fribbledom

@TheGibson @dude @fribbledom yes, that would make sense. baluns usually convert between coaxial and differential lines, and can also convert between line impedances - a very common type is the ones that take a type-F coaxial plug (75Ω) from the back of a radio tuner and adapt it to a balanced ladder line (300Ω) to the antenna.

@TheGibson @dude @fribbledom and then there's the extremely-simple type we used for the antennacane that ensures balanced signal but doesn't change impedance - just take the coaxial line and wrap it around a ferromagnetic core a bunch of times. the inductance takes out any high-frequency common-mode signal, leaving the differential-mode signal unimpeded.

@TheGibson @fribbledom we even designed new equipment (our RPi-based counters) using BNC for inputs, since we still have racks and racks of the cables and many drawers full of fittings.
oscilloscopes generally have BNC sockets for their inputs (that's what the probes generally use) and they're the largest sections on the patch panels at the APS.

@fribbledom haven't used one, but seen those, know what those are etc

@fribbledom I recognize the one on the right and hate it, for no immediately appearant reason. The ones I ran into all had paint on them, didn't they?

@fribbledom For splicing/tapping co-ax cables! (Never used 'em or owt, mind..)

@fribbledom I have a BUNCH of those, and ends to make at least 12 cables.

@fribbledom I have those.. in an old box of cables, that i also don't know what they are for :P

@fribbledom Never seen or used them but they look like adapter-y splitter-y things for old coaxial cables you get from TV aerials, so guessing they're for back in ye olde days when you'd rip TV by splitting it and sending it into a VHS recorder? How far off am I?

@fribbledom OH GOD PUT THEM AWAY! We had those on our school IT class network and they where crimped badly so the network went down all the time.

@fribbledom I have heard about them in legends told by old netadmins, before there were switches... I have a "T" connector on a shelf that serves as a museum (next to a couple old Pentium CPUs), as a reminder of those dark times.
@fribbledom i still use bnc t-pieces from time to time, but for SDI (digital video) :)

@fribbledom I once owned an ISA-NIC with rj45 and bnc, but never used the bnc part :)

Of course! My DVB-C still uses coax cable between optical converter and TV. But most memories are from 16 bit days when used to connect Sega Mega Drive (Genesis) to TV's antenna socket 😁

@fribbledom Coax type "BNC" plug and splitters
Use in radio VHF/UHF

@fribbledom only the leftmost for coaxial ethernet in a school. Not sure what the others achieve


Stab in the dark. . . auto cigarette lighters?
And yes, a long time ago, experimenting in high school.


Not quite. It's networking equipment. I guess most of the other replies already gave it away though 😆

@fribbledom Why do you say "still"? We use them regularly.

@fribbledom Or are they not BNC adapters and terminators as they appear to be?

@fribbledom I really would like to know why the "still". Is there some new connector that's superceding them?


Because I've personally haven't seen anyone use them in the last 15 years or so. Glad you still hear there are still people who do.

@fribbledom I feel like we're talking past each other here, because RJ-45 connectors are in no way suited for what BNC connectors are for. Was BNC the connector of choice back when ethernet used coax?


Yep. I get it you still use them for other coax equipment?

@fribbledom They're the de facto, and possibly also de jure, standard connector for oscilloscope probes, function generator outputs, and coaxial connectors on any sort of electronics test equipment, except when the higher bandwidth of the more expensive N connector is needed.

@ND3JR @fribbledom Thank you. I was just about to say how much I missed BNC connectors. You nailed the reasons why on the head perfectly.

@fribbledom Been a while. I was always told the data would fall out of the end if you didn't put a cap on.

@fribbledom I have some in use as we speak carrying an IRIG-B time signal from a high precision satellite clock.

@georgem @fribbledom

That is a very common connector type on aircraft as well.

@fribbledom Yes. 2 Weeks ago when trying to measure how a potato can be used as a radio.

Function generator, a few coax cables and actually 4 used channels on the oscilloscope. I had to use a split connector to connect the potato and the oscilloscope with the AM signal.

@fribbledom Yeah, I remember playing with those as a kid. What were they called? "Legions of Power" or something like that. Remember the big battery powered walker our dad helped us build.

@dantheclamman @fribbledom Looks like coax connectors to me.

I still occasionally touch them when I have to hook up an oscilloscope to check electrical signals.

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