Prototype Interior View

Copyright 2007 by John Blankenbaker

The prototype and production units were very similar but production units were neater than the prototype shown above.

One point in the design of the unit was to avoid special parts. For example, the transformers in the power supply were filament transformers for vacuum tubes.

Several standard cabinets were purchased and the Bud “Grand Prix” enclosure was selected. Only a few unique parts were required such as the front panel and the rear panel.

The logic motherboard, and the power supply printed circuit board (seen above in an edge on view) had to be designed.

Wiring from the power supply and from the front panel was made long enough so that these parts could be laid back from the logic board.

There were remarkably few errors in the prototype which had not been bread boarded or tested prior to the construction of unit above. A few jumper wires were required in the prototype to correct minor logic errors.

Prototype Interior

Rear View. Air was drawn in on the right and exited the enclosure in the center. At the extreme left there is the fuse holder and the 110 VAC line cord (not shown in this photo). To open the case, the “handles” on the end were removed and the two panels were unscrewed from the top half which could then be removed.