opening up a 288c

**MERDY** · April 27th, 2010, 11:07 AM

have never tried this before , besides the allen screws how do i seperate the housing as i want to get it going for the project this week.
with friends we are setting a 210 replica with 515b and a 803 horn it will be a mono system with a mono cart to play those mono records all this in a large basement in new york city
cant wait and will post pics

**bowtie427ss** · April 27th, 2010, 11:46 AM

Don't remove the allen screws if you plan to use the driver, if you disassemble it beyond removing the cover and diaphragm, it will lose most of it's magnetic charge.

**Altec Best** · April 27th, 2010, 01:12 PM

What is it that you are trying to do with this driver ??

Bill Hanushack at Great Plains Audio will re-charge magnets with any Rebuild and or diaghram replacement.

**MERDY** · April 27th, 2010, 05:48 PM

i found another 288c with a shifted magnet and was wondering if it was possible as it is the only single i have for the experiment as the other pair i cannot acess till sunday

bowtie where did you hear about magnets loosing charge ? about 30 years ago when i set some jbl boxes on fire due to the woofers crapping out after the fire all i saw was the metal frame of the driver it was in the rain for a good 3 months and i remember taking the magnet out before i put it in the trash

and it might have been week but i still used it to put on car bodies to check if they were filled with bondo etc the original alnico rust gizmo.

**Steve Schell** · April 27th, 2010, 08:55 PM

Merdy the six allen cap bolts are a legacy of the Lansing field coil drivers. In these early units the top plate/diaphragm/back cover assembly was removed and sent to the factory for servicing. When the permanent magnet 288 driver was introduced the top plate could no longer be removed, so the user-replaceable diaphragm assembly was developed.

If you remove the six cap screws on a 288 and pry up the top plate, nearly all of the magnet charge will be lost. It is certainly possible to do this and repair a driver internally, but then it will have to be recharged before being placed back in service.

**Leland** · April 27th, 2010, 11:42 PM

About the Allen bolts.....my are rusty on top.....is it possible to remove one at a time to clean that up....and reinstall.......with out damaging the magnetic charge?

I suppose there must be some torque spec to tighten to.

I guess from reading your info....best to just clean the tops of the bolts with-out removing....