cleaning air gap

[glen101]

Hi
I need to clean the air gap in a 2405 slot.
I have tried:
Compressed air
a brass shim
cloth
paper & card
BUT all I can do is move the flakes of grit around in circles.

Any ideas on how to clean would be appreciated.

Also any guidance on installing the new diaphragm?

Thanks Glen

[cooky1257]

Hi
I need to clean the air gap in a 2405 slot.
I have tried:
Compressed air
a brass shim
cloth
paper & card
BUT all I can do is move the flakes of grit around in circles.

Any ideas on how to clean would be appreciated.

Also any guidance on installing the new diaphragm?

Thanks Glen

Masking tape?

[Harvey Gerst]

In the old days at JBL, we used masking tape wrapped around a shim to clean voice coil gaps.

[boputnam]

That hasn't changed.'zactly...


...all I can do is move the flakes of grit around in circles.nIf the "grit" has anything ferrous about it, they might be attracted to the motor (magnet), making removal difficult. Best hope is to get them stuck to some tape, as described.

[robertbartsch]

Yeah, keep metal ferrous chips away from the open gap; these motors are strong and they will attract metal dust fast.

If gap must remain open after cleaning, put some masking tape over it. The blue color used for interior and exterior painting works well and tends not to leave residue.

[Harvey Gerst]

With the tape in the gap, you move it forward and up at the same time, working your way along the circular opening. When you have some particles sticking to the tape, discard and use a fresh piece of tape.

[glen101]

Thanks all,
look like tape is the answer. I will give it a try tonight.
Any tips for loading the new diaphragm?

Regards Glen

[Harvey Gerst]

Thanks all,
look like tape is the answer. I will give it a try tonight.
Any tips for loading the new diaphragm?

Regards Glen
In the words of the great Elmer Fudd:

"Be vewy, vewy carfuw."

[robertbartsch]

...I beleive the slots have alignment pins to guide the new frame into place. Be sure to use only authentic JBL frams....

..make sure the nose, horn and all parts including bolts are clean and dry before assembly. Compressed air works well.

good luck!

[mech986]

In the words of the great Elmer Fudd:

"Be vewy, vewy carfuw."

Harvey, it can't be said any better!! :applaud:

[robertbartsch]

Oh yeah, I forgot the most important point.

DONT over tighten the slot nose since it can twist/move over the top of the new fram and destroy it.

I bought a used 075 where the previous owner did this and destroyed the diaphragm.


...sounds dumb but it happens.