KeyTronic Magnetic Reed Board, Teensy

[OldIsNew]

I recently acquired a KeyTronic magnetic reed switch board. No case just the internals.

orig_small.jpg (345.42 KiB) Viewed 2554 times

PCB_back_sm.jpg (346.69 KiB) Viewed 2554 times

nocaps1_sm.jpg (274.86 KiB) Viewed 2554 times

nocaps3_sm.jpg (317.78 KiB) Viewed 2554 times

nocaps2_sm.jpg (252.25 KiB) Viewed 2554 times

It's hard to read in the picture, but it carries a sticker dated 4/80.

date_sm.jpg (204.61 KiB) Viewed 2554 times

They are difficult to see but you can make out one of the reeds in this picture:

reed1_sm.jpg (251.8 KiB) Viewed 2544 times

It took a while to trace out the matrix because there was either some sort of clear solder mask or epoxy type resin coating both sides of the board, including all the electrical contacts and I had to scrape it off each of the key contacts. Once that was done it wasn't too hard to figure out . A number of system keys were on their own columns and I ended up bridging them to other columns that had open spaces on their rows in order to save pins on the Teensy. Otherwise even the Teensy++2.0 would have been a bit tight for pins.

wires2_sm.jpg (391.5 KiB) Viewed 2554 times

wired_back4_sm.jpg (342.75 KiB) Viewed 2554 times

wired_front4_sm.jpg (201.48 KiB) Viewed 2554 times

I really like this board! It's working nicely and I typed this post on it. The switches are quite smooth and have a nice "clack" to them. I think my next project is going to be fashioning some sort of wooden case for it. It's interesting looking as is but a nice case would be a plus!

[Daniel Beardsmore]

Wow, overkill space bar mechanism to deal with the height of the switches!

[seebart]

Your building quite an impressive vintage collection OldIsNew! #DTA7 ! KeyTronic magnetic reed is one switch I'd love to try. Real nice.

[Chyros]

Very nice, these are interesting switches. Makes sense that they're smooth - I seem to recall having heard they're rather stiff though.

[OldIsNew]

Thanks everyone.

Very nice, these are interesting switches. Makes sense that they're smooth - I seem to recall having heard they're rather stiff though.

The switches are smooth and if by stiff you mean that the springs are on the heavy side - they are. By the highly scientific nickel test they are somewhere between 65 - 70 gm. I like them!

And yes the space bar mount may be somewhat over engineered, but it sure works well - very stable and easy to take the space bar on and off.

[ohaimark]

I had a tenkeyless KeyTronic Magnetic Reed keyboard early on in my collecting days. I wrote the wiki page for the switches, I think.

I like the tiny plink noises that the reeds make when they engage.

[Sangdrax]

You always find some of the neatest old boards.

Also, for the case, there's custom amp case makers like FrontPanelExpress who can do the work. Just the top panel should be less than a hundred and fifty for nice thick aluminum, and they can anodize it all sorts of colors.

[OldIsNew]

Also, for the case, there's custom amp case makers like FrontPanelExpress who can do the work...

Thanks for the tip! I'll check them out, sounds like they make some nice stuff.

[OldIsNew]

Well until I potentially invest in a real front panel like Sangdrax suggested, I went ahead and made a wooden frame case that at least holds the board at a proper angle and does look better than two flat pieces of 2x4. Also, I had to desolder all the ICs, resistors, caps, etc. in order to cleanly isolate the rows and columns for connection to the Teensy, but didn't particularly care for all those bare solder pads. So ... file this under anal compulsive ... I covered the IC pads with little Mylar rectangles, then trimmed the all the IC legs, resistors, etc. and put them back in place with dabs of clear silicon calk (so no electrical contact). Ok maybe it's a little nutty to do that, but I think it looks better.

desoldered.jpg (289.61 KiB) Viewed 2345 times

frame.jpg (371.29 KiB) Viewed 2345 times

[seebart]

Well until I potentially invest in a real front panel like Sangdrax suggested, I went ahead and made a wooden frame case that at least holds the board at a proper angle and does look better than two flat pieces of 2x4.

Oh,what an elegant solution. I have several vintage keyboards that lack a case, this Micro Switch would be my first choice for a custom case:

Spoiler:

IMGP0155.JPG (973.57 KiB) Viewed 2340 times

keyboards-f2/micro-switch-sw-10876-t112 ... o%20switch