Extenders being wrongly called "baluns"???


Active Member
How come people here are wrongly calling "extenders", devices that allow you to extend HDMI (or other) signals from one location to another via CAT5/5e/6, etc. cable, "baluns"?

For instance one post specifically calls the "Atlona AT-HD4-SI40SR" a "balun" while the manufacturer specifically calls it an "extender".

A "balun" based on CB's own Wiki are "Transformers that convert BALanced an UNbalanced signals." (SIC) and while certain extenders may do that, that's not what the purpose of an extender is.

I've discussions with the techs from some of the companies that manufacture extenders, and not once did they use the word "balun", they always used the word "extender." One of the extenders I use extends XLR over Cat5e, and while they may have a transformer in it to transform the signal over the long length of Cat5e, it's balanced throughout so there's no unbalancing involved.

Shouldn't we be using the proper term?

For the record my auditorium uses 5 different Cat5e extenders:
- HDMI to HDBaseT going up to BOH projector
- HDMI to HDMI going down to FOH monitor
- VGA to VGA going down to FOH monitor
- USB to USB going down to FOH keyboard/mouse/memory stick
- 4xXLR to 4xXLR going down to FOH mixer

And the DI boxes we use to connect computers to mixers could be called "baluns", they're not referred that way.

p.s. I'm posting it in the "multimedia-projection-show-control" forum because that's where several of the threads misusing the term reside.

p.p.s. How can you add definitions to keywords, "balun" is defined but "extender" isn't but it should be. Also the definition for "balun" is worded poorly, "Transformers that convert BALanced an UNbalanced signals."


Well-Known Member
Fight Leukemia
I agree. A balun is a transformer used for balancing (common mode rejection), impedance matching and galvanic isolation. Some extenders are made with baluns, some are not. Of the list above, VGA to VGA is the only type of extender likely to use baluns.

A simple test is whether the device requires power to work. Baluns don't require power. However, that test can't be made if the port being extended natively supplies power, such as USB.


Active Member
Out of my list the only one that doesn't require power is the XLR extender, a Radial Catapult. All the rest have external power either at one end or both ends.
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CB Mods
Premium Member
Fight Leukemia
As a frequent offender, it is primarily the same reason that people will call satellite television "cable". When a certain technology offers the first means of doing something, or if it is popularized, in our lazy means of communication we tend to use that term even when it is incorrect. This is why we use product names to describe similar products even when there are substantial differences (how people will call any ellipsoidal reflector spotlight a "Leko" when that has so many changes from a Source-4). A balun was an early means of extending a video signal. Example.

Certainly, as we go further away from analog, the likelihood of an extender using balun technology is becoming increasingly rare.

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