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7A12: Difference between revisions
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The Evaluation Engineer for the 7A12 was [[Peter Starič]], co-author of the book "Wideband Amplifiers" with Erik Margan. | The Evaluation Engineer for the 7A12 was [[Peter Starič]], co-author of the book "Wideband Amplifiers" with Erik Margan. | ||
There were two mistakes, concept errors, that doomed the 7A12 from day | There were two mistakes, concept errors, that doomed the 7A12 from day one. The first was in deciding to use the Tektronix IC process (the "Standard Process") for the signal path. This process had an Ft of only 1 GHz, too slow for a plugin expected to provide 150MHz bandwidth in the fastest mainframe, the 7704. | ||
The second day | The second day one mistake, later pointed out by Tom Rousseau, was to arrange the two channels vertically. Roy wanted to be able to go from one sensitivity (deflection factor) to another without having to go through all the sensitivities in between as happens with a rotary switch. The vertical row of push buttons was attractive an functional. The complexity required two boards. The non-obvious problem with this is that the two channels, each on its own circuit board, would not be two identical boards. The boards would be mirror images! That is more expensive and more complex. | ||
Tom Rousseau designed a new dual trace plugin with discrete components that had 75 MHz bandwidth and much less expensive to manufacture. He did this on his own, not at management's request. Management liked it. It became the 7A18. Later Tom had the advantage of a later, faster IC process. He used the M84 (155-0078-xx), already in production for the 485, and circuitry similar to the 7A18. This became the 7A26, the best selling Tektronix product of all time. | |||
See https://vintagetek.org/100000-7a26-plug-in/ | |||
{{BeginSpecs}} | {{BeginSpecs}} | ||