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Richard Long
01-29-2010, 11:49 AM
hi,

here are two fotos of a diaphragma from 2441 with a little mistake on the dome. there is no hole in the dome. is the dia technical 100% o.k.? it works ok. Is it a manufacturing error, or a later becoming mistake ?

http://i227.photobucket.com/albums/dd158/RichardLong1/Bild022-2.jpg
http://i227.photobucket.com/albums/dd158/RichardLong1/Bild020.jpg

Chas
01-29-2010, 12:05 PM
:)There should not be a hole in the diaphragm.

Richard Long
01-29-2010, 12:15 PM
:)There should not be a hole in the diaphragm.

yes it sounds still :D;)

Earl K
01-29-2010, 12:19 PM
http://i227.photobucket.com/albums/dd158/RichardLong1/Bild022-2.jpg

The location of "said imperfection", suggests it was caused by a "slip" of a screwdriver into the dome .

If so, that's a "user error" ( by persons unknown ) not a manufacturers' error .

BTW, you'll never hear such a small nick .

http://i227.photobucket.com/albums/dd158/RichardLong1/Bild020.jpg

Sorry :(

SMKSoundPro
01-29-2010, 01:51 PM
Agreed! You'll never hear it, and now we are reminded again to use a NON magnetic screw-driver around these drivers!!!

Scotty.

Steve Schell
01-29-2010, 03:14 PM
LOL, Earl I was thinking the same thing. Somebody went "oops", then removed the diaphragm and pushed the dent out with their fingernail. I've never done that of course...

SMKSoundPro
01-30-2010, 06:10 AM
Nope, nor I...

4343
01-31-2010, 10:59 PM
Nope, nor I...

Although it's odd that both my 2420 dia's have similar impressions. One came to me that way back in '83, but for $20 I did not complain as it matched the one I had...

Beowulf57
02-01-2010, 05:30 AM
Even better: a screwdriver dented the dome of a D131 (honest I didn't do it!) and the problem was solved using pliobond and a q-tip stick to pull the dome back out. The pliobond was then removed very carefully with methyl hydrate and q-tips.:applaud:;)

Richard Long
02-01-2010, 09:23 AM
Even better: a screwdriver dented the dome of a D131 (honest I didn't do it!) and the problem was solved using pliobond and a q-tip stick to pull the dome back out. The pliobond was then removed very carefully with methyl hydrate and q-tips.:applaud:;)

thatīs a good idea ! is it possible to do it the same way with domes of 24xx ?


if you pay 500$ :( in germany for one good looking 2441, i think i have to await for a perfect dia !

toddalin
02-01-2010, 09:45 AM
Not a screwdriver dent, but a lesson to anyone who replaces a diaphram.

Note that there are two dents and look at the spacing. I suggest that the person disconnected the input spade lug and let it go. These lugs have a ferrite basis! It was attracted to the magnet and the two "prongs" made the dent.

Been there/done that. :biting:

Beowulf57
02-01-2010, 07:30 PM
thatīs a good idea ! is it possible to do it the same way with domes of 24xx ?

In the case of the 24xx, I would probably remove the diaphragm from the unit and use a q-tip by itself to gently massage the dent out from behind. Provide a soft but firm support on the opposite side while you attempt this. I have not attempted this myself...so if anyone has experience, please pipe in. The difficulty with the D131 is that one cannot get behind the dome without removing it from the cone...hence the pliobond trick.

Richard Long
02-02-2010, 07:47 AM
... and use a q-tip by itself to gently massage the dent out from behind. Provide a soft but firm support on the opposite side while you attempt this.


good idea ;)

toddalin
02-02-2010, 09:23 AM
good idea ;)


You will not "hear" the dent as it is. Try to fix it and screw it up and you may not hear anything.

Richard Long
02-23-2010, 09:53 AM
next question, are the fotos below showing 2441 Dias? They are fixed in a 2441 but itīs no alu dia. itīs manufactered in 1997 and has a number on the ring of the backside 61435

http://i227.photobucket.com/albums/dd158/RichardLong1/DSC00939.jpg

http://i227.photobucket.com/albums/dd158/RichardLong1/DSC00942.jpg

which fluid can i take to clean the smokerings on the backside of tthe dia??

louped garouv
02-23-2010, 10:46 AM
maybe they are 2445 Ti diaphragms?

scott fitlin
02-23-2010, 09:22 PM
Not a screwdriver dent, but a lesson to anyone who replaces a diaphram.

Note that there are two dents and look at the spacing. I suggest that the person disconnected the input spade lug and let it go. These lugs have a ferrite basis! It was attracted to the magnet and the two "prongs" made the dent.

Been there/done that. :biting:GOOD EYES! I agree this makes sense as to what I see too.

Manufacturing error? NO!

End user error? YES!

herki the cat
03-21-2010, 08:47 AM
hi,here are two fotos of a diaphragm from a 2441 with a little mistake on the dome. there is no hole in the dome. is the diaphragm technically 100% o.k.? it works OK. Is it a manufacturing error, or a late mistake ?

http://i227.photobucket.com/albums/dd158/RichardLong1/Bild022-2.jpg
http://i227.photobucket.com/albums/dd158/RichardLong1/Bild020.jpg


Richard Long, you are lucky there were no holes in the dome & it was a simple little dent which you will never hear....In 1950, my first 594-A had a small hole which i successfully repaired with a small film of Altec cone cement. Motor refinish was straight forward in the RCA Model Shop.

I had retrieved this 594-A Driver from three inches of water in a garage basement full of WECO, 8-B, 9-B, & 10-A, 60-Watt Amplifiers in the estate of a friendly Altec Service Technician in Philadelphia. Yes! 60 watts from the 10-A stage with PP-PL 242-C tubes, & 1500 volts B+ to drive nine 555-W's on each of two 12-A WECO horns of the Warner Bros Vita Phone.

I saw the trashing of one of these systems in the 1950's conversion of the Boyde Theater for the Awesome Cinerama. You 50 year old fellows don't know what you have missed __Cinerama 180 degree screen with Post WW-2, modern two-way, vacuum tube amplifier-horn sound.

cheers, herki the cat

louped garouv
03-25-2010, 10:28 AM
...
I saw the trashing of one of these systems in the 1950's conversion of the Boyde Theater for the Awesome Cinerama. You 50 year old fellows don't know what you have missed __Cinerama 180 degree screen with Post WW-2, modern two-way, vacuum tube amplifier-horn sound.

cheers, herki the cat
http://www.widescreenmuseum.com/widescreen/ac-cinerama.htm


wish i whad been around to hear/see this kind of stuff....
but then again, the 1980s was a good time to be a young child IME
:)

thanks for sharing some tidbits so the uninformed amongst us can learn some more about some of the ways of the past....

Progneta
04-01-2010, 01:24 PM
Are those diaphragms original or after market?

-G

Richard Long
04-02-2010, 02:16 AM
in the picture link you can see another defect on a phaseplug. is this an manufactoring error?

http://i227.photobucket.com/albums/dd158/RichardLong1/DSC00977.jpg

itīs taken from a 2445j and it has a newer phasplug, i think itīs the same as in the 2450j. is there a sounddifference between the 2445jīs with the black/metal phaseplug?