Shaun Merrigan
Classic Electronic Restoration, Vacuum Tube Audio, Technical History, Photography
Tag: Shaun Merrigan
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Originally posted in November, 2023 This post documents my investigation of Sprague 672D Electrolytic capacitor failures in HP 70000 MMS test equipment. Background Introduced in 1986, The HP 70000 Modular Measurement Sysem (MMS) is a highly configurable test equipment system comprising spectrum analyzers, DVM, power meter, oscilloscope, signal generators, phase analyzer and more. I have…
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Originally posted in September, 2021 The Apple IIe personal computer was manufactured from January 1983 through November 1993. I purchased an Apple IIe several years ago and put it into storage at the time. I recently pulled it out from storage and began the process of refurbishing it. Part of that process was rebuilding the…
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Originally posted in June, 2021 Introduced in 1966, the Tektronix 106 Square Wave Generator is a signal generator which can produce fast rise (<1nS @50 ohm loads positive or negative going) or high amplitude (120 Volts, high impedance load) square waves from 10Hz to 1MHz. It is used for oscilloscope calibration, risetime testing and for…
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This was originally posted in December, 2017 Tektronix 556 Dual Beam Oscilloscope Testing: Vertical Bandwidth I have been doing some basic testing of my Tektronix 556 Dual Beam Oscilloscope, and I have documented some parts of this process. I have also captured images of the traces, which I will share here. Test Setup: Tektronix 556,…
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Originally posted in January, 2017 I was recently fortunate enough to acquire a Tektronix 556 Dual Beam Oscilloscope with many accessories and in good condition. Unfortunately, the cooling fan on the scope was very loud and more concerning, it emitted an alarming metal on metal contact sound. After verifying basic operation of the oscilloscope, I decided…