Editing Monogram SMK derivative series

{{infobox dswitch
| image name        = USw LXBB01 -- recognition.jpg
| manufacturer      = 
| product code      = 
| contact mechanism = [[Metal leaf]]
| switch mount      = [[Plate mount]]
| keycap mount      = SMK cruciform (unconfirmed)<br>[[Cherry MX mount]]
| switch type       = [[Linear]], [[Clicky]], [[alternate action]]
| actuation force   = 
| introduced        = 
| family            = 
}}

'''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.<ref name="KBT" />

==Nomenclature==
[[File:USw LXBB01+RB01 branding.svg|121px|thumb|Base branding is an unclear monogram]]

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 <ref name="DT-A-III" />, 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 MX mount|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  ?",<ref name="KBT" /> 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:

{| class="wikitable variants-table"
! !! Designation !! Keycap mount !! Type
|-
| [[File:USw LXBW03 -- variants table.jpg|175px]] || USw LXBW03 || SMK?          || Alternate action illuminable
|-
| [[File:USw LXBW04 -- variants table.jpg|175px]] || USw LXBW04 || SMK? (angled) || Alternate action illuminable
|-
| [[File:USw LXBB01 -- recognition.jpg|175px]]    || USw LXBB01 || Cherry MX?    || Momentary
|-
| [[File:USw LXRB01 -- recognition.jpg|175px]]    || USw LXRB01 || Cherry MX?    || Momentary, heavier weight?
|-
| [[File:Clicky_SMK_preview.jpg|175px]]           ||            || 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]],<ref name="DT-A-II" /> 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<ref name="DT-A-II" />
*NTC KB-5060 
*NTC KB-5260
*1TF101 - clicky variant

==Gallery==
===SMK J-M0404 mount===
The following switches appear to be SMK J-M0404 mount.

<gallery widths=250 heights=227>
File:USw LXBW03.jpg | USw LXBW03, unknown origin; the switch is illuminable, but no LED is fitted here
File:USw LXBW04.jpg | USw LXBW04, unknown origin
</gallery>

===Cherry MX mount===
The following switches appear to be Cherry MX mount, and come from the [[1KB101ATUS]] keyboard.

<gallery widths=250 heights=187>
File:USw LXBB01 -- assorted switches.jpg       | Assorted USw LXBB01 switches
File:USw LXRB01 and LXBB01 -- in situ.jpg      | LXBB01 and LXRB01 in situ
File:USw LXRB01 and LXBB01 -- disassembled.jpg | LXBB01 and LXRB01 disassembled
File:Clicky_SMK.png                            | Clicky variant disassembled - found in a 1TF101 keyboard
</gallery>

==References==
<references>
<ref name="KBT">KBtalKing — [http://kbtalking.cool3c.com/article/10126 ⊙.⊙台灣怪軸～HK黑軸～1KB101ATUS⊙.⊙]</ref>
<ref name="DT-A-II">Deskthority — [https://deskthority.net/keyboards-f2/smk-or-maxi-switch-led-version-t15841.html SMK or Maxi Switch LED version?]</ref>
<ref name="DT-A-III">Deskthority — [https://deskthority.net/viewtopic.php?t=8359]</ref>
https://deskthority.net/viewtopic.php?t=8359</references>

[[Category:Designations]]
[[Category:Unknown switches]]
[[Category:Linear switches]]
[[Category:Alternate action switches]]
[[Category:Illuminable switches]]
[[Category:Keyboard switches with Cherry MX mount]]
[[Category:SMK vintage linear derivatives]]
[[Category:List of all keyboard switches]]