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HYS 8: 10 MHz to 20 MHz Upgrade

Author: Dieter Wächter

This document describes how to do the frequency- doubling of the Z 80- processor at the GSP 2101.

You need the following parts:

• 1 crystal, 20 MHz in HC-18 housing
• 2 ceramic- capacitors 15 pF, Voltage: doesn\u2019t matter, structural module: 2.5mm
• 2 small cable- straps

You'll get all parts in every electronic- shop.

Notes:

• Observe all the electric specifications! (Risk of electric shock ....)
• Take care of the rules for static protection. If you don\u2019t know them, you\u2019ll find them at:

Upgrade- Process:

1. Store a Bulk- Dump. (This is not absolute necessary, but only for safety)
2. Pull all plugs out of the GSP.
3. Remove the six side-panel screws
4. Remove the rear-panel top center screw
5. Remove the front-panel top center hex- bolt
6. Remove the lid
7. Press on the cable- holder on the mainboard which holds the pins of the cable of the output-potentiometer and pull on the cable. The cable must slip out of the cable holder. Hey man... be careful don\u2019t damage the cable-holder or tear the cable apart! It must slip very facile out of the holder!
8. Pull the plug from the front-panel-board, which is connected to the mainboard (the lower plug of the ribbon cable)
9. Remove the 5 front-panel hex- bolts
10. Remove the complete frontpanel.
11. Pull off the knob of the cabinet- emulator- switch
12. Remove the 4 XLR-connector screws
13. Remove the 4 XLR-connector- board screws
14. Pull the XLR-connector- board
15. Remove the valve- holder- screw
16. Mark the valves with V1 and V2 with a pen.
17. Pull the valves
18. Remove the hexagon- valve- holder- standoff
19. Cut the two cable- straps which hold the cables from the secondary side of the power- transformer.
20. Pull the two power- transformer- plugs.
21. Remove the 2 lower screws of the heat sink
22. Remove the 7 phone-plug-plastic-nuts
23. Remove the 4 DIN-plug screws (there are different versions! At the older 2101s there are no screws!)
24. Remove all the screws which hold the mainboard (Also different versions... you have to look!)
25. Uncase the mainboard.
26. Locate the 10 MHz- crystal (X2). You find it between the Z80- processor and the battery.
27. Locate the capacitors C 233 and C 234. You find it right beneath the crystal. There is a writing "25" on them.
28. Unsolder the crystal. It\u2019s a double- sided board, so don\u2019t use a unsoldering- pump, use a forceps, heat the pins and pull it out of the vias.
29. Unsolder C 233. Same process
30. Unsolder C 234. Same process
31. Now suck the rest of the plumber's solder out of the vias. Use a unsoldering- pump to do this.
32. Solder the 20 MHz- crystal to the board at the same position where the 10 MHz- crystal was. Be careful, don\u2019t cause soldering- bridges!
33. Solder the two 15 pF- capacitors to the board at the same position where C 233 and C 234 was. Same process.
34. Make sure that there are no soldering- bridges.
35. Mount the main board.
36. Mount the 4 DIN-plug screws
37. Mount the 7 phone-plug-plastic-nuts
38. Mount the 2 lower screws of the heat sink
39. Mount the two power- transformer- plugs
40. Fix the cables of the transformer with the two cable- straps
41. Mount the hexagon- valve- holder- standoff
42. Mount the valves. V1 where V1 was, V2 where V2 was.
43. Mount the valve- holder
44. Mount the XLR-connector- board
45. Mount the knob of the cabinet- emulator- switch
46. Mount the frontpanel
47. Mount the ribbon cable- plug from the front-panel-board
48. Put the ribbon cable from the output-potentiometer back into the cable- holder
49. Check if everything is on the right position.
50. Mount the lid
51. Switch on the GSP 2101 an watch the display. The Software- version is shown some seconds later. An "a" appears after the software- version. (e.g. 3.00.00.a if you had an 3.00.00 past)

Congratulations! Now you are frequency- doubled.

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