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* [[Category:Manual needed]] ''please add service manual'' | * [[Category:Manual needed]] ''please add service manual'' | ||
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The '''Tektronix 11401''' is a digitizing scope with three | The '''Tektronix 11401''' is a digitizing scope with three plugin bays accepting [[:Category:11000 series plugins|11000-series plugins]] and [[7000-series plug-ins]]. | ||
Project manager of the 11400 series was [[Tom Rousseau]], who was also project manager for the [[7854]]. | |||
The 11400 engineering team included some of the main people from the 7854 project. | |||
<!-- Using random equivalent time sampling, it can acquire up to eight channels at 300 MHz, six channels at 600 MHz, or up to 3 channels at 1 GHz. --> | <!-- Using random equivalent time sampling, it can acquire up to eight channels at 300 MHz, six channels at 600 MHz, or up to 3 channels at 1 GHz. --> | ||
The 11401 mainframe uses equivalent time sampling at a rate of | The 11401 mainframe uses equivalent time sampling at a rate of 20 MHz (20 Msps). | ||
Each sample has 10 bits of resolution. | Each sample has 10 bits of resolution. | ||
It is capable of displaying eight separate 10 bit resolution traces at one time. | It is capable of displaying eight separate 10 bit resolution traces at one time. | ||
The mainframe is fully remotely programmable over RS-232 or GPIB. | The mainframe is fully remotely programmable over [[RS-232]] or [[GPIB]]. | ||
This mainframe accepts up to three plugins with differing numbers of channels and bandwidths. | This mainframe accepts up to three plugins with differing numbers of channels and bandwidths. | ||
For example, each [[11A52]] plugin allows two inputs at | For example, each [[11A52]] plugin allows two inputs at 500 MHz bandwidth (50 Ω only input impedance). | ||
The [[11A34]] plugin allows four inputs at | The [[11A34]] plugin allows four inputs at 300 MHz bandwidth, and the [[11A32]] allows two channels at 300 MHz. | ||
Three 11A34 plugins then allow up to 12 channels of information, | Three 11A34 plugins then allow up to 12 channels of information, | ||
but the mainframe limits the number displayed at any one time to eight. | but the mainframe limits the number displayed at any one time to eight. | ||
The other four channels may still be used for triggering. | The other four channels may still be used for triggering. | ||
The [[11402]] and (later) [[11403]] and [[DSA600]] mainframes allow up to | The [[11402]] and (later) [[11403]] and [[DSA600]] mainframes allow up to 1 GHz of bandwidth | ||
with an [[11A71]] | with an [[11A71]] with one 50 Ω input, or two 50 Ω inputs in the (later) [[11A72]]. | ||
{{MissingSpecs}} | |||
Resolution is up to 10 ps horizontal and 10 bits vertical, with 10,240 points of memory. | Resolution is up to 10 ps horizontal and 10 bits vertical, with 10,240 points of memory. | ||
==Internals == | |||
Note: The photos of the "Prototype 11401" are of a scope that said [[11331]] on the front panel. | Note: The photos of the "Prototype 11401" are of a scope that said [[11331]] on the front panel. | ||
The 11401 uses the [[156-2622-00]] [[SDI]] controller IC (U330). | The 11401 uses the [[156-2622-00]] [[SDI]] controller IC (U330). | ||
== Vertical Signal Path == | === Vertical Signal Path === | ||
Each of the three plug-in bays in the 11401 has a dedicated sampler. | Each of the three plug-in bays in the 11401 has a dedicated sampler. | ||
The sampling clock is common to the three samplers. | The sampling clock is common to the three samplers. | ||
The sampling pulse is generated by an ECL 2-input OR gate being fed SAMPLE_CLOCK and delay_5ns(invert(SAMPLE_CLOCK)). | The sampling pulse is generated by an ECL 2-input OR gate being fed SAMPLE_CLOCK and delay_5ns(invert(SAMPLE_CLOCK)). | ||
This produces | This produces 5 ns pulses with rise time around 1 ns, which are fed to a discrete NPN differential pair operating | ||
in a clipping current-switch mode, resulting in faster edges. | |||
resulting in faster edges. | |||
The output of the differential pair drive a strobe generator IC, U1040, which is an M453 die, | The output of the differential pair drive a strobe generator IC, U1040, which is an M453 die, | ||
packaged as part number [[155-0320-00]] or 155-0320-01, depending on the mainframe's serial number. | packaged as part number [[155-0320-00]] or 155-0320-01, depending on the mainframe's serial number. | ||
U1040 has three sampling strobe outputs, which are fed to the sampling gates. | U1040 has three sampling strobe outputs, which are fed to the sampling gates. | ||
The plug-in connector's differential "DISPLAY" pins are connected to the samplers by coaxial cable, | The plug-in connector's differential "DISPLAY" pins are connected to the samplers by coaxial cable, | ||
i.e. there are no high-speed amplifiers in the mainframe's signal path. | i.e. there are no high-speed amplifiers in the mainframe's signal path. | ||
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The contents of the RAM may have many points depending on the size of the acquisition window. | The contents of the RAM may have many points depending on the size of the acquisition window. | ||
The "Waveform Compressor" board takes the contents of the acquisition RAM and renders it to 512 points on the horizontal axis for display. | The "Waveform Compressor" board takes the contents of the acquisition RAM and renders it to 512 points on the horizontal axis for display. | ||
==Links== | ==Links== | ||
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[[Category:11000 series mainframes]] | [[Category:11000 series mainframes]] | ||
[[Category:RS-232 interface]] | |||
[[Category:GPIB interface]] |