Thursday, February 23, 2017

This and that

Worked on one of the 1401 systems at CHM today, replacing a front panel switch we thought was bad but the problem persists. The Start Reset button does not reset the machine properly. This means that once an error condition arises, the system must be power cycled to run anything else. 

Participated in an oral history session with Bob Feretich who, along with Grant Saviers and others, created the Tape Emulator box that helped restore the first 1401's Tape Adapter Unit (TAU) about a year faster than would otherwise have been possible, and provided virtual tape drives and educational program support. 


I picked up a nice aluminum box to mount my DDS VFO into, beginning to cut the openings and mount up parts. I removed the rotary encoder and jacks from the circuit board and will place them on the face of the metal box. The LCD is also to be installed on the face of the box. 


I picked up this unit, which uses a 'magic eye' tube to indicate when a resistance or capacitance bridge is balanced, in order to determine the component value. It also tests for leakage at a variety of voltages up to about 450V, which is a great way to test and reform old electrolytic capacitors. 

I inventoried the parts that likely need replacement and ordered them from Digikey. Essentially it is all but one of the capacitors inside, since they were types that are notorious for becoming leaky with age. When the parts arrive, I will replace the old components and power this puppy up. 

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