NE 6041QAA restoration

[5415551212]

Greetings all I recently picked up a Northern Electric 6 Button 1A2 'Line Select Key Box'
Stamped  NE-6041QAA
Some of the contacts were shorted so i have been investigating how the buttons work
Turns out there is a foam pad that helped the contacts stay apart that deteriorated to grey dust.
I drilled the rivets and tapped them out to 10-32 and now am contemplating what to replace the foam pad with?
Any advice would be appreciated.
 

[RB]

Hi Don't know nuthin bout that box, but you might try an OLD mouse pad...
NOT a new one, they are to thin, and too dense.
Good luck

[Key2871]

I would try an air conditioner filter, it's foam and thin
Or you can get a replacement key from me, I have a few removed from NOS key sets..
$15.00 plus postage, PM me if interested

[5415551212]

Thanks for the ideas!
time to scrounge around and see what I can find.

[Key2871]

The thing to remember here, it's that maintains some cushion and helps maintain the proper gap between contacts. If that isn't maintained after you effect repairs it may not work properly.
And contacts may need to be readjusted because of the gap problem with a new foam.

[5415551212]

After looking around and at the I am going to try some layers of used bike inner-tube.
A coworker of mines uses them for everything.
The rubber will be a good insulator and has lots of give.
I can add or subtract layers easily.
Stay tuned.

[Key2871]

Well if it doesn't work out I have several if the 636A keys. So if you want any, I might have some.
Look under for sale from me you'll find them.
The picture shoes no buttons but I do have those for the keys, Cables too for connection.
I'll make you a good deal.

[5415551212]

Thanks Ken!
This is mostly just for the experience of tinkering around at this point.
Seems like these foam pads are the dumpster sentence for key units so seems like it would be wise to document how to replace the foam.

[Jim Stettler]

Thanks Ken!
This is mostly just for the experience of tinkering around at this point.
Seems like these foam pads are the dumpster sentence for key units so seems like it would be wise to document how to replace the foam.

long shot: The foam is spec'ed in a document somewhere.

The spec  would be in design documents. and maybe the practice.

Practices should show part #'s  for the foam. the part # is the best key for the search.
Just my opinion
Jim

[Key2871]

Obviously those units have a life span of a good long time. Thing is a lot of these units are out living that life.
I'm sure when they were designed they said these will out live the service of the equipment, as in a newer better system will be in use long before those sets would actually be used.

And for the most part they were correct, I'm just not sure they were considering collectors still using this equipment long after the fad lasted.
I've never seen any information on replacing the things such as foam pad in keys.

I've read several BSPs that say when a product fails send it back to Western Electric for repair.
Or remove the faulty component and replace.
In this case it would be the entire key unit, and they would wire in a new 6041 and be done.

Personally I like these old units better than the newer stuff. I've had many but 1A2 is still a strong useful equipment. That may just out live some EKS equipment.

I had merlins liked the features as long as the feature pack worked. But if that failed, well it's just not great.
Where 1A2 is just still chugging away like a well maintained locomotive.

[5415551212]

Well the thin rubber bike inner-tube works great.
I like it becasue rubber is a good insulator and it has some give like the foam.
a 7/16 - 1/2" long 8-32 screw and nut should be good to replace the rivets.
I had to play around with it a few times to get good spacing.
I only have one other key phone and the foam in that key set is disintegrating also but the contacts are still looking good for now, so ill probably be doing this again soon.
Cheers all

[Babybearjs]

Interesting. I've never run across any of these with a foam insulator. all of the ones I have don't use the foam... based on that, I wouldn't be really worried about replacing it. hope you get it working...

[5415551212]

Interesting. I've never run across any of these with a foam insulator. all of the ones I have don't use the foam...

I have not seen any WE key phones that use another type of insulator. Its hard to see unless you take the key unit out or look closely from the side.
Post a picture of what else they used as a spacer if you have one disassembled? I would be curious to see what else they used.

based on that, I wouldn't be really worried about replacing it.

Each button closes 3 contacts, the one circled in red in this photo had lost its foam and was always shorted. The other two worked. So you could get odd issues.

The unit is re assembled and all the buttons and / contacts work as they are supposed to now.

[Key2871]

Well I've been working on and with key phones for the better part of 40 years, I've never seen a 636A key with out foam insulating the layers of switches.
The older they get the more they tend to deteriorate, and this can perhaps make it difficult to see the foam.

But that is indeed what I've seen, be it Western, Northern, or ITT. They were all built the same, rivits were different but that's about the only difference.

I have not worked on SC or AE key sets so I can't be 100 percent, but I'd think they too were also foam.

Yes the key operates three sets of contacts, the middle actually setting first as there is a slight high spot on the key actuator.

But when I first d
Started working on key sets I worked on were Western.
And the second were ITT sets, 2564, 564 and 830, and 2830. Everything for the most part on these sets were just about all the same thing.
The only thing different with ITT keys on 830/2830 sets was the way the lock pin screw was removed from the key for signaling, it came out clock wise instead of CCW as Western are.

So John, what did you see as insulators in your key sets?
I never thought about using innertube for a insulator replacement. But hey, as long as it works. Good job.
It's nice to see others finding ways of keeping these sets going.

[5415551212]

Thanks for that info Ken

I never thought about using innertube for a insulator replacement. But hey, as long as it works. Good job.
It's nice to see others finding ways of keeping these sets going.

Thanks yeah, my co worker uses them for everything, I never would have though of it.