Monogram SMK derivative series
 | |
| Switch type | Linear, Clicky, alternate action |
|---|---|
| Sense method | Metal leaf |
| Keycap mount |
SMK cruciform (unconfirmed) Cherry MX mount |
| Switch mount | Plate mount |
Monogram SMK derivative series refers to a series of SMK J-M0404 series clones and derivatives, distinguishable by the use of an unclear but readily identifiable monogram. There is a suggestion that these switches were manufactured in Hong Kong.[1]
Contents
Nomenclature
The base of each switch is branded with a monogram that appears to depict the letters 'C', 'S', 'C' and 'O', possibly in this order (reading outside to inside and top to bottom). These switches have never been found in any branded keyboard, so the identity of the manufacturer remains a mystery. Even the orientation of the monogram is not known for certain.
However, an interesting observation, based on an old NTC brochure [2], can suggest that this switch, or at least the MX mount variant of this switch, went under the name of NTC mechanical keyswitch. The switch used in the NTC KB-5060 keyboard has the same appearance and the monogram symbol at the bottom.
Description
This series is a fairly close copy of SMK J-M0404 series. The types examined so far have two raised contact ridges along the crossbar of the stationary contact, just as with SMK switches; HTK switches only have one central raised area. The rear of the movable contact is copper colour in photos, suggesting that the whole contact is made of phosphor bronze; the front appears to be plated.
Variants
The series contains a number of different switch designs. Some have a keycap mount that appears to be SMK compatible, while others have a keycap mount that appears to be Cherry compatible. alps.tw wrote, "是台灣參考NEC軸而改良的嗎? 為了配合Cherry MX的鍵帽 ?",[1] the implication being that they are Cherry MX mount, which appears to be the case from photos of the switches in question (USw LXBB01 and LXRB01). Some switches with USw LX designations are likely to need reclassifying with USw LM designations once the keycap mount is confirmed. The clicky variant uses a white slider, has a click leaf and uses a Cherry MX keycap mount.
There are linear and clicky variants. The HTK switch is very similiar to the clicky variant.
Known examples include:
| Designation | Keycap mount | Type | |
|---|---|---|---|
 |
USw LXBW03 | SMK? | Alternate action illuminable |
 |
USw LXBW04 | SMK? (angled) | Alternate action illuminable |
|
USw LXBB01 | Cherry MX? | Momentary |
 |
USw LXRB01 | Cherry MX? | Momentary, heavier weight? |
 |
Cherry MX | Momentary, clicky |
Alternate action variants
Two alternate action designs exist. One design (seemingly older) is a direct clone of SMK J-M0404 alternate action,[3] while the other is a simplified design whose latching mechanism is exposed at the top to the ingress of foreign objects. Both types are notable for being illuminable: slots that run through the switch from top to bottom allow an LED with long legs to be fitted, reaching all the way down to the solder side of the PCB.
Keyboards
- 1KB101ATUS (USw LXBB01, LXRB01; 1987)
- Some Apple II clone keyboards[3]
- NTC KB-5060
- NTC KB-5260
- 1TF101 - clicky variant
Gallery
SMK J-M0404 mount
The following switches appear to be SMK J-M0404 mount.
USw LXBW03, unknown origin; the switch is illuminable, but no LED is fitted here
USw LXBW04, unknown origin
Cherry MX mount
The following switches appear to be Cherry MX mount, and come from the 1KB101ATUS keyboard.
Assorted USw LXBB01 switches
LXBB01 and LXRB01 in situ
LXBB01 and LXRB01 disassembled
Clicky variant disassembled - found in a 1TF101 keyboard
References
- ↑ 1.0 1.1 KBtalKing — ⊙.⊙台灣怪軸～HK黑軸～1KB101ATUS⊙.⊙
- ↑ Deskthority — [1]
- ↑ 3.0 3.1 Deskthority — SMK or Maxi Switch LED version?
