Teletype Model 28 Mark I, Mark II, Mark III Differences

Mark I Keyboard - LK1, LK2? - same as Mark II but different connectors?

2-row connector on keyboard base
IMG_3160.JPG (4644861 bytes)
LESU with 2-row connectors
IMG_3156.JPG (4929123 bytes)
Wiring Diagram
IMG_3161.JPG (2291999 bytes)
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Mark II Keyboard - LK3, LK4, LK5, LK7 

- some Mark II keyboard parts drawings

Keyboard transmitter
IMG_3153.JPG (5421348 bytes)
Keyboard mechanism protector bar
IMG_3154.JPG (6503873 bytes)
Keyboard cover (hood) top view
Mark III above, Mark II below
IMG_3165.JPG (3540064 bytes)
Keyboard cover (hood) bottom view
Mark III above, Mark II below
IMG_3167.JPG (4455035 bytes)

Mark III Keyboard - LK6, LK8 and on

keyboard transmitter
IMG_3149.JPG (7080849 bytes)
No protector bar Keyboard cover (hood) top view
Mark III above, Mark II below
IMG_3165.JPG (3540064 bytes)
Keyboard cover (hood) bottom view
Mark III above, Mark II below
IMG_3167.JPG (4455035 bytes)

Mark I Printer - LP1, LP2? - almost the same as Mark II?

slotted ribbon carriage rail (black)
slotted typebox carriage rail (steel)
(note that this is a flat piece with larger holes than Mark II)
IMG_3207.JPG (4944343 bytes)
Type box carriage rail A-1324
Teletype Part 150844
IMG_3209.JPG (4709980 bytes)
2-row electrical connector
IMG_3157.JPG (4935355 bytes)
2-row connector J-1301
Teletype Part 151815
IMG_3210.JPG (3720405 bytes)

Mark II Printer - LP3, LP4, LP5, LP6, LP7, LP8, LP9 

- some Mark II printer parts drawings

Left side of printer
IMG_3150.JPG (2976827 bytes)
solid ribbon spool retainer clips
IMG_3163.JPG (2987514 bytes)
slotted ribbon carriage rail (black)
slotted typebox carriage rail (steel)s
IMG_3172.JPG (4709704 bytes)
slotted ribbon carriage rail (black)
slotted typebox carriage rail (steel)
IMG_3205.JPG (4222234 bytes)

Mark III Printer - LP10 and on

Left side of printer
IMG_3148.JPG (3374819 bytes)
wire ribbon retainer clips
IMG_3164.JPG (5107358 bytes)
round hole ribbon carriage rail (black)
unslotted typebox carriage rail (steel)
IMG_3176.JPG (4536422 bytes)
Hybrid or updated? Mk II solid ribbon retainer clip and Mk II left side with Mk III round hole ribbon carriage rail (black) and Mk III unslotted typebox carriage rail (steel)
IMG_3208.JPG (6876327 bytes)