Unusual KPT-84

User avatar
Daniel Beardsmore

12 Jul 2014, 00:20

Since I am enjoying a typical English summer, I don't know for certain when I'll get chance to take the remaining photos of the [wiki]KPT KPT-84[/wiki] that lowpoly sent me, since I need a sunny day. Tomorrow looks promising though.

Photos round 1 (I often take them in several rounds as I identify issues with the previous round and make up a list of photos to re-take; once I have a full set of photos I'll put them straight onto the wiki):

[Edit: cross-posted to alps.tw's topic at KBT, so really some photos of the keyboard are in order, as he won't have seen lowpoly's sale topic! Round 1a:
KPT KPT-84 top.jpg
KPT KPT-84 top.jpg (574.56 KiB) Viewed 2041 times
KPT KPT-84 bottom.jpg
KPT KPT-84 bottom.jpg (536.92 KiB) Viewed 2041 times
Round 1b: may as well have the model and FCC ID while I'm at it:
KPT KPT-84 model and FCC ID.jpg
KPT KPT-84 model and FCC ID.jpg (1010.74 KiB) Viewed 2040 times
]

Firstly, the date on the chip doesn't come close to matching the date on the rear:
KPT KPT-84 chip.jpg
KPT KPT-84 chip.jpg (562.33 KiB) Viewed 2042 times
KPT KPT-84 years.jpg
KPT KPT-84 years.jpg (549.47 KiB) Viewed 2042 times
Also note the brands on the chip — very strange: Daewoo, Appian (that's a blast from the past), and Aron Hi-Tech.

The PCB is marked KPT:
KPT KPT-84 PCB inscription.jpg
KPT KPT-84 PCB inscription.jpg (624.1 KiB) Viewed 2042 times
Here's a topic about Aron keyboards:

http://deskthority.net/keyboards-f2/aro ... -t673.html

Backspace is not stabilised! The keycap supports a stabiliser, but none is fitted:
KPT KPT-84 backspace is not stabilised.jpg
KPT KPT-84 backspace is not stabilised.jpg (901.8 KiB) Viewed 2042 times
I haven't checked the enter key, but the upper row of the enter keycap is very stiff.

I was expecting Taiwan Tai-Hao APC switches, but instead I got what I am guessing is Himake or Hua-Jie (depending on which date you believe):
KPT KPT-84 switches.jpg
KPT KPT-84 switches.jpg (891.94 KiB) Viewed 2042 times
The design is curiously an intermediate between AK-CN2 and AK-CN2 (2). The stationary contact is the all-over-"gilted" mini design used in Xiang Min ("XM") switches and Hua-Jie AK-CN2 (2) switches, as well as some other switches that I'm guessing are from Himake or Hua-Jie.
KPT KPT-84 switch stationary contact.jpg
KPT KPT-84 switch stationary contact.jpg (483.09 KiB) Viewed 2042 times
The movable contact design is half-way in between the two!
KPT KPT-84 switch inside.jpg
KPT KPT-84 switch inside.jpg (492.67 KiB) Viewed 2042 times
KPT KPT-84 switch movable contacts rear.jpg
KPT KPT-84 switch movable contacts rear.jpg (498.76 KiB) Viewed 2042 times
KPT KPT-84 switch contacts.jpg
KPT KPT-84 switch contacts.jpg (543.64 KiB) Viewed 2042 times
All switch parts:
KPT KPT-84 switch.jpg
KPT KPT-84 switch.jpg (365.67 KiB) Viewed 2042 times

User avatar
Muirium
µ

12 Jul 2014, 01:56

Maybe Appian had a cut of the action in the switches, too…

The only apt description for the relationships between all those clone makers is truly: incestuous. My guess is that this kind of madness is quite common in all manner of generic components that we aren't interested in. Switches just happen to be the sweet spot for being the right size to investigate by hand, and actually making a difference.

User avatar
Daniel Beardsmore

12 Jul 2014, 02:15

It depends how a switch is made. Matias designs and sells switches (bizarrely unbranded, for no known reason) but they have no manufacturing capacity that I know of. The switches are assembled by Dongguan Gaote, who themselves don't make the parts either or, at least, not all of them. I don't know how many factories are involved.

The Chinese and Taiwanese love retooling, and I suspect this is just another Himake/Hua-Jie variant. It's not the usual font for the opposite-corner style of numbers, though; the only switch the font matches is this one:

[wiki]Hua-Jie AKF Cherry MX mount[/wiki] (not confirmed as Hua-Jie though; by rights I should rename it with a USw number)

Taiwan Tai-Hao APC switches have no parts in common with any other product. Xiang Min and Hua-Jie switches share all the metal parts, but the plastic parts are moulded separately. YH-B also has metal parts that don't match anyone else.

maxrunner

13 Jul 2014, 13:55

Are these switches identical to the ortek FX?

User avatar
Daniel Beardsmore

13 Jul 2014, 16:24

They are not numbered the same, but the only way to tell what switches your Ortek has is to open them up. Multiple switches used the same numbering and some switches used several different types of numbering, so you can only tell what switch you've got by opening one up for a look.

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