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Heathkit H8 key switch type?
Posted: 19 Jan 2016, 02:06
by snuci
I just saw an eBay auction for some Heathkit computer equipment and remembered that I was curious about my H8 computer key switches. I took a couple of pictures below. I think I'll have to take it apart but does anyone recognize these key switches with an exterior spring? These cannot be foam and foil because they come individually in the kit and I'm fairly certain they are soldered in. The plate on top that holds the spring in feels metallic but I'll have to check for sure if/when I take it apart.
The
Heathkit H8 was produced in 1977 so the switches would be from that time period. They have no markings I can see from the top. Sorry for the bac pics. This is from a camera phone in bad light and they are zoomed in.
Anyone have any ideas?

- H8 - key pad
- H11 - key pad.jpg (250.73 KiB) Viewed 2878 times

- H8 - key switch left side
- H11 - key switch left side.jpg (225.69 KiB) Viewed 2878 times
EDIT: I mistakenly mixed the model number with a similar H11 but this is, in fact, an H8 so any reference to H11 is actuallyH8 (my picture file names are H11).

- H8 - key switch right side
- H11 - key switch right side.jpg (240.61 KiB) Viewed 2878 times

- H8 - key cap top
- H11 - key cap top.jpg (227.01 KiB) Viewed 2878 times

- H8 - key cap bottom
- H11 - key cap bottom.jpg (213.91 KiB) Viewed 2878 times
Posted: 19 Jan 2016, 12:41
by terrycherry
The switch have something look like the Oak Full-Travel Membrane. It could be the early Oak switch??
http://deskthority.net/wiki/Oak_Full-Tr ... wv-Sun-3-3
Great vintage switch found.
Posted: 19 Jan 2016, 17:41
by snuci
It is a good guess and the same guess that someone else mentioned offline but these key switches are discreet individual key switches and there is no membrane. Might be the same manufacturer but not the same switch type. Here's a portion of the Heathkit H8 assembly manual that shows a drawing of them:

- heath h8 Instruction.jpg (62.92 KiB) Viewed 2811 times
Posted: 19 Jan 2016, 18:07
by terrycherry
Wow, it's rare to see the assembly switch on the operation manual.
Is there have the maintenance manual about the computer or keyboard?
Sometimes it includes the switch manufacturer on that manual.
Posted: 19 Jan 2016, 18:12
by snuci
Heathkit was a manufacturer of kits (assorted parts that you assembled yourself to build the final product). The computer came as a kit so the assembly manual always had detailed steps. This is just the step telling you how to solder the key switches to the PCB board. There was also a material list so that you could check and confirm that you had all the parts to start with. This material list doesn't list the manufacturer names so I don't yet know who made it.
Posted: 19 Jan 2016, 18:25
by terrycherry
So the only way is desolder one switch to see the internal.
And if our member - Daniel Beardsmore saw it, he can help you.
Here's his site(some switches doesn't create or write on deskthority)
http://telcontar.net/KBK/
Posted: 19 Jan 2016, 18:30
by snuci
Daniel was the person I mentioned that was offline.
I will desolder the switch this weekend and see what it is if no one can tell.
Posted: 21 Jan 2016, 00:48
by snuci
So, the result are in after not being able to wait.
It's... Stackpole. In the Wiki already as a
Stackpole discreet switch.

- H8 Stackpole - switch bottom marking
- H8 Stackpole - switch bottom marking.jpg (362.69 KiB) Viewed 2757 times
Here are some more pics. Notice the top ring is actually metal along with the spring. It travels down with the key stem. Unfortunately, the switch is sealed so I can't open it. Anyway, mystery solved. This probably isn't too interesting to others but at least I know what's there for old switches from 1977 or so.

- H8 Stackpole - key switch unit
- H8 Stackpole - key switch unit.jpg (209.16 KiB) Viewed 2757 times

- H8 Stackpole - key switch side
- H8 Stackpole - key switch side.jpg (231.1 KiB) Viewed 2757 times

- H8 Stackpole - key switch side
- H8 Stackpole - key switch other side.jpg (258.34 KiB) Viewed 2757 times

- H8 Stackpole - key switch and key cap
- H8 Stackpole - key switch and key cap.jpg (219.91 KiB) Viewed 2757 times

- H8 Stackpole - H8 front panel computer board
- H8 Stackpole - computer board.jpg (488.34 KiB) Viewed 2757 times
Posted: 21 Jan 2016, 01:15
by Chyros
Ah so that's what they are! I saw these on eBay recently:
http://www.ebay.co.uk/itm/Stackpole-SPS ... SwKIpV~FiZ
Seller says they're "Stackpole SPST" switches, but if you google that you get a bunch of different Stackpole switches. I'm guessing these are electromechanical/Ohmic in origin? The wiki doesn't mention anything about it at all.
Posted: 21 Jan 2016, 03:28
by terrycherry
That is surprising!
I can see the whole switch finally.
Thanks the vintage share and found~