The Man Whose ‘Scopes We All Wanted To Own: Walter LeCroy

We’re sorry to say that back in May we missed the passing of Walter LeCroy, the man whose name appeared on some of the most desirable and higher-spec oscilloscopes to be found. If you’ve never used a LeCroy ‘scope then you’ll still have benefited from his work, as a pioneer of storage oscilloscopes even the more modest instruments which now grace our benches owe much to his legacy.

The linked article about his life comes from the successor to his company, and describes his early experience in scientific instrumentation and in particular in the field of high-energy physics,before the development of the first digital storage oscilloscopes. In particular it mentions the 1971 “Waveform Digitizer”,a device that used a transmission line and a series of sample-and-hold circuits to grab and digitize a sequence of readings with a single ADC. It goes on to describe the model 9400 series from the 1980s which with its successors are probably are what come to mind for many of us when thinking of a LeCroy ‘scope, the familiar big square box with integrated computer-style CRT, floppy drive, and small printer.

Here in 2023 it’s not beyond the bounds of possibility to design your own digital oscilloscope simply by pairing a fast microcontroller with an appropriately expensive ADC chip. To look back at the effort required to produce one with a high bandwidth using 16-bit microcomputer parts and 1980s silicon is to be reminded that we stand upon the shoulders of giants.

Thanks [Daniel Valuch] for the tip.

Oscilloscope Repair Projects Still Probing For Success

lecroy-9450-oscilloscope-repair[Luke] isn’t able to declare total victory yet. His LeCroy 9450 oscilloscope repair project has seen some success, though. The glitchy screen seen above is just one of the problems it had, but has now been fixed. When [Luke] got his hands on it, this was one of three screen states: the other two being normal operation or completely dead. Replacing the screen connector was all it took, so he moved on to the second part.

This one is much less trivial. Only one of the two channels works—which might be the point at which many would abandon the repair—but it’s still a fine single-channel scope. [Luke] continued to trouble-shoot by disassembling the bottom of the case and breaking out the device’s schematics. He traced the circuit and found one module that is suspect (and is looking for help finding a replacement). Unfortunately, the problems don’t end there. Another unknown problem is causing erroneous signals on the displayed waveforms. It’s an odd issue but it really feels like he’s close to solving this one!