is a 1.1 Balun the same as a 1.1 unun ?

[Buick Mackane]

Is there any difference in their construction ? Far as i can tell by googling they are basically the same thing, Any help appreciated

[ch25]

BALanced-UNbalanced vs UNbalanced-UNbalanced
Different animals.
Unun: https://www.qsl.net/dk7zb/Baluns/MTFT.htm it's used for unbalanced antennas like random wire, endfed etc.
Balun is used for connecting balanced antennas like dipole to unbalanced coax. https://www.qsl.net/dk7zb/Baluns/current_balun.htm
Chris

[Buick Mackane]

Thanks for the reply CH-25

Yes i know what they are used for and what the abbreviations stand for,

According to this link from a well known ham gear manufacturer a 1.1 balun - 1.1 unun - common mode choke - line isolator are all different names for the samething.

[ch25]

They are obviously wrong.

[Ant]

Even experienced people get the names wrong. A choke is a choke, some call them a balan, when a balun does a different job of course, as does an unun.

[Piggly]

No, they are not the same thing.

However, if you look at the main part of the three items they are just a 1:1 transformer, some with a core and some without.

Take that 1:1 and connect one winding to a dipole and the other to the coax feeder and you have a balun.
Take the 1:1 and connect the bottom of each winding together as a common ground and a monopole or long wire/ended to one side and the coax feeder to the other and you have an un-un.
Take the 1:1 and connect coax in and out but “lengthwise” through the windings and you have a common mode choke.

Now, different numbers of turns might be needed in each winding, varying with the core type, frequencies and how much coupling you need but that’s really the basis.

So no, they are different but I understand where the “all the same thing” comments come from.

[Buick Mackane]

No, they are not the same thing.

However, if you look at the main part of the three items they are just a 1:1 transformer, some with a core and some without.

Take that 1:1 and connect one winding to a dipole and the other to the coax feeder and you have a balun.
Take the 1:1 and connect the bottom of each winding together as a common ground and a monopole or long wire/ended to one side and the coax feeder to the other and you have an un-un.
Take the 1:1 and connect coax in and out but “lengthwise” through the windings and you have a common mode choke.

Now, different numbers of turns might be needed in each winding, varying with the core type, frequencies and how much coupling you need but that’s really the basis.

So no, they are different but I understand where the “all the same thing” comments come from.

Thanks for the explanation, I Did read online that it depends on the wiring configuration as to whether it's classed as a unun or balun, Seem's like iv'e been using a balun as a choke on my EFHW, So it's not really suited to the job, At least i think its a balun bought it years ago, Can anybody confirm exactly what it is ?

Iv'e ordered a FT-240-43 Core, I'll use that to wind a choke.

[Piggly]

In principle, yes, the wiring is what makes it behave differently. To be accurate, there are slight difference in the way each behaves so they aren’t precisely the same but in principle they are basically so.

A balun can work for an EFHW but won’t bring the impedance down to around 50Ohm if it’s a 1:1; if the two sides are dc isolated (not cross-connected) then decking one leg of the secondary would work ok-ish. It might work better if it were a quarter wave rather than half wave.