Enclosed VS Open Frame choke

[Jonas]

I have a question regarding choke construction; open frame vs enclosed.  (open frame Hammond 153-159 series and enclosed choke Hammond 193 series)

I heard years ago that using an enclosed choke is a bad idea, but I cannot remember why or if even true?  Your thoughts?

[sluckey]

Not true.

[AmberB]

Does it make any functional difference if the choke is open or enclosed?

[tubeswell]

Does it make any functional difference if the choke is open or enclosed?

Depends whether you're a 'function' or 'form' person LoL. One type has bell covers, the other type doesn't.

[Jonas]

thanks everyone!

[valvetones]

The chokes with endbells are fully shielded yes?
The type with no end bells would then possibly mess with the magnetic field of the power and output transformer perhaps? Just guessing here.

Thinking maybe it would couple the power supply fields with the output transformer fields if all three pieces of iron are in close proximity.

Yes ? No? Maybe so?

[tubeswell]

The chokes with endbells are fully shielded yes?
The type with no end bells would then possibly mess with the magnetic field of the power and output transformer perhaps? Just guessing here.

Thinking maybe it would couple the power supply fields with the output transformer fields if all three pieces of iron are in close proximity.

Yes ? No? Maybe so?

No difference in EM fields - the end-bells are purely for looks. The EM-flux density extends out into the space outside the laminations, and this happens whether or not you have end bells.