L-Pad 10285 & 10359 and 11397 Capacitors

[ralphj]

Sorry in advance if the answer to this question is well known but a search has not thrown up a definitive answer.
LPot 8 ohm Type 10285 .
Is this or an equivalent available from jbl or any electronic parts house?
All four on my recently purchased 4310's are useless due to some type of oxidation build up on the resistance coils.
Caps on Type 3111 Network 10359 and 11397.
Are these oil & paper type and so as I can see 'waterline' on the outer covering are they best replaced? Same question as before , do jbl or anyone else stock replacements or equivalents.

Thanks in advance
John

[Zilch]

Replace the 8-Ohm L-Pads with similar from Parts Express or other suppliers. Pay attention to the requisite shaft length and body size to fit.

You might try disassembling the original L-Pads (remove the cap on the rear) and cleaning the elements with an appropriate solvent, such as DeOxit, made for the purpose.

The original capacitors are mylar, not paper in oil. You're seeing the wax sealant separating. Replace with metallized polypropylene types of the same value, and then tear one of the originals open to see the construction.

I don't know where the sand originated, but you can pretend it's from California....

[ralphj]

Replace the 8-Ohm L-Pads with similar from Parts Express or other suppliers. Pay attention to the requisite shaft length and body size to fit.

You might try disassembling the original L-Pads (remove the cap on the rear) and cleaning the elements with an appropriate solvent, such as DeOxit, made for the purpose.

Thanks for that, Zilch
I think that its too late for the coils, they have broken in places where the rotator has snagged on the oxidation.

Much appreciated
John

[Baron030]

Hi Ralphj

The JBL 8 ohm - #10285 L-Pad carries a 15 watt rating.
Parts Express carries 2 different models in this size.
One has a 3/8” shaft length and the other with 1” shaft length.

Baron030

[ralphj]

Have got the crossover networks out for inspection, I cannot figure out how to get the Hi out as I cannot see any screw heads. There must be something very simple that I'm missing.
Does anyone know, do I just push the cardboard tube out of the cabinet? assuming the HF driver is a push fit into this tube.
John

[ralphj]

Front view of the cabinets.
See previous post for question on the removal of the HF driver.
Thanks
John

[Zilch]

Screws are behing the thin aluminum bezel or "trim ring," glued to the face of the tweeter.

It's difficult to remove without bending it, but sometimes, on older units like that, it can be close to falling off, and carefully removed.

Gently heating the bezel with a hair dryer or heat gun will assist with the persuasion....

[ralphj]

type 3111 Crossover networks.
Cylindrical capacitor is part no 11937, 3mF capacitance.
Box capacitor is part no 10359, 13.5 mF capacitance.
L Pads are part no 10285 8 ohm.

[ralphj]

hey
Thanks Zilch for the quick reply.
You wouldnt happen to know what voltage the Caps are rated for?.
Do they degrade over time and should be replaced as a matter of course after a certain age?
Thanks
John

[Zilch]

Your caps appear to be in good shape physically.

Most DIYers here would likely replace them with new bypassed metallized polypropylene type.

Consider, however, that doing that may decrease the resale value.

If they're playing fine, I'd let them be....