TKB - Touch Keyboard Sequencer - Build Part 3 - Main Board. (Resistors, Caps, etc).
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Before we begin there are some preliminary pics of the PCB
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I'll start of with least temperature sensitive components such as the IC header sockets, resistors & diodes.
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These modern headers connect the Main PCB to the rest of the keyboard. In vintage TKBs, the headers used were slightly different:
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Notice the silver arrow which is used to check the header orientation.
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Looks like the four 22pf caps on the left need to be swapped for 100pf.
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Looks like the surface mount 100n caps need to be soldered to the underside of the PCB across pins 5/4 & 11/10. of the LM 324s --- to be confirmed.
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The SMD caps lie under the three LM 324s on the top right
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Notice the bud box below is self powered.... in fact it has two PSUs, and was once part of a much larger system.
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Top pics of the main TKB PCBs (vintage on left)
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The underside of the PCBs.
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*** Click here for the TKB Build Index ***
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*** Click here for the TKB Build Index ***
Before we begin there are some preliminary pics of the PCB
| Mouser #: | 571-5103308-3 | |
| Mfr. #: | 5103308-3 | |
| Manufacturer: | TE Connectivity | |
| Desc.: | Headers & Wire Housings 16P 2 ROW HEADER LP | |
Notice the silver arrow which is used to check the header orientation.
Vintage TKB headers.
Back to the Modern PCB:
The LM 324 is a low power quad Op-Amp
Almost finished the easy part ... soldering the resistors, diodes, caps & headers..
I think its a good time to stop and compare this board to a vintage TKB main board. This one is a unrestored TKB -- also from the late 1970s.
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