Jansen electrostatic tweeter questions.

Archived from groups: rec.audio.tech (More info?)

On Fri, 15 Apr 2005 04:43:36 -0500, none <Vampyres@nettaxi.com> wrote:

>One of the individual radiators is badly damaged and I was thinking of
>paring them down from four to just three as it might be impossible to
>get replacement parts for anything this old. This shouldn't be a
>problem should it?

The coupling transformer is designed for 4 cells, not 3. At best you'll have
a 25 % impedance mismatch on the secondary... I would suggest a rebuild, or,
at least a diaphragm change.

>Also they've got a heavy buildup of grime on them from extended
>storage. What's the best way to clean them off?

You should dismantle the drivers, clean and dry everything plastic save the
diaphragms, then maybe change the diaphragms. Jantzen spares are nearly
impossible to find, but home made units based on Saran wrap lightly rubbed
with finely powdered graphite can be fine, check the web for some how-to's.
You can then re-assemble the units, test them and enjoy them.

>(I was thinking a bit
>of simple green followed by rinsing with water, then blowing off with
>compressed air. Or would it be safe to use a contact cleaner?

Don't do anything like this : you'd damage or destroy the units.

Archived from groups: rec.audio.tech (More info?)

On Fri, 15 Apr 2005 14:20:15 +0200, François Yves Le Gal
<flegal@aingeal.com> wrote:

>On Fri, 15 Apr 2005 04:43:36 -0500, none <Vampyres@nettaxi.com> wrote:
>
>>One of the individual radiators is badly damaged and I was thinking of
>>paring them down from four to just three as it might be impossible to
>>get replacement parts for anything this old. This shouldn't be a
>>problem should it?
>
>The coupling transformer is designed for 4 cells, not 3. At best you'll have
>a 25 % impedance mismatch on the secondary... I would suggest a rebuild, or,
>at least a diaphragm change.
>
>>Also they've got a heavy buildup of grime on them from extended
>>storage. What's the best way to clean them off?
>
>You should dismantle the drivers, clean and dry everything plastic save the
>diaphragms, then maybe change the diaphragms. Jantzen spares are nearly
>impossible to find, but home made units based on Saran wrap lightly rubbed
>with finely powdered graphite can be fine, check the web for some how-to's.
>You can then re-assemble the units, test them and enjoy them.
>
>>(I was thinking a bit
>>of simple green followed by rinsing with water, then blowing off with
>>compressed air. Or would it be safe to use a contact cleaner?
>
>Don't do anything like this : you'd damage or destroy the units.
>
Thanks for the info.
One of the units is cracked along the edge. Will this effect it's
function? I did manage to flex it back into shape and all else about
it seems fine.(looks like some of hired help had tried to pry them out
and cracked it. The speakers had been in storage in the back of my
warehouse for some years.)
Do you have any links to sites on these tweeters and how to
dismantle/service them?
Also if I use Saran wrap you mention rubbing with graphite powder?
Excuse my denseness, while I'm very profficient in repair of most
things electronic, my knowledge on electrostats is scant.
Why the rub with graphite?
Would it be better to use a good grade of mylar and film and perhaps
use an adhesive to coat it with the graphite?( I'm guessing that the
graphite is to improve the acoustic qualities of the mylar film)
I do have the equipment to do microfilm coating so I'd be able to put
down the adhesive really fine.(1-3 mils)
Then use a micro spray-gun to dust down the graphite.
Thanks again for the assist.