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T7100: Difference between revisions
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The '''Tektronix T7100''' (P/N 154-0783-00 with P31 phosphor) is the CRT used in the [[7104]] and [[R7103]] 1 GHz | The '''Tektronix T7100''' (P/N 154-0783-00 with P31 phosphor) is the CRT used in the [[7104]] and [[R7103]] analog 1 GHz scopes. | ||
It features a [[Micro-channel plate CRT|micro-channel plate]] electron beam amplification stage. | It features a [[Micro-channel plate CRT|micro-channel plate]] electron beam amplification stage. | ||
[[File:Micro-channel plate diagram.jpg | thumb | 550px | right | MCP diagram<br />(click image to enlarge)]] | |||
Compared to non-MCP high-speed tubes, the T7100 uses reduced beam current and acceleration voltage | Compared to non-MCP high-speed tubes, the T7100 uses reduced beam current and acceleration voltage | ||
to achieve high deflection sensitivity, eliminating the need for high amplifier output voltages, thereby boosting | to achieve high deflection sensitivity, eliminating the need for high amplifier output voltages, thereby boosting | ||
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an electrostatic scan-expansion lens that increases deflection 4.5 times vertically and 4 times | an electrostatic scan-expansion lens that increases deflection 4.5 times vertically and 4 times | ||
horizontally, before it hits the micro-channel plate (MCP). | horizontally, before it hits the micro-channel plate (MCP). | ||
The deflection structures are described in US Patent 4,093,891. | The deflection structures are described in [https://patents.google.com/patent/US4093891 US Patent 4,093,891]. | ||
The scan-expansion lens is a "box lens" design, which is discussed on pages | The scan-expansion lens is a "box lens" design, which is discussed on pages 53−55 | ||
of the | of the ''[[Media:7104_maintenance.pdf|7104 maintenance document]]''. | ||
The MCP consists of parallel channels of 25 μm diameter and offset at a slight angle to the beam. | The MCP consists of parallel channels of 25 μm diameter and offset at a slight angle to the beam. | ||
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of secondary electron emission like in a [https://en.wikipedia.org/wiki/Photomultiplier photomultiplier]. | of secondary electron emission like in a [https://en.wikipedia.org/wiki/Photomultiplier photomultiplier]. | ||
A final 10 kV potential accelerates the beam across a 3 mm gap toward the phosphor coating. | A final 10 kV potential accelerates the beam across a 3 mm gap toward the [[phosphor]] coating. | ||
The beam amplification is sufficient to view a [[Media:Tek7104-200ps-singleshot.jpg|single-shot event at 200 ps/Div]] with the naked eye. | The beam amplification is sufficient to view a [[Media:Tek7104-200ps-singleshot.jpg|single-shot event at 200 ps/Div]] with the naked eye. | ||
The Micro-channel plate's amplification degrades irreversibly with operation, in proportion to the log of total charge passed per channel or display area. | |||
For this reason, continued operation with a steady trace and especially at large beam currents must be avoided. | For this reason, continued operation with a steady trace and especially at large beam currents must be avoided. | ||
The 7104 contains a CRT protection circuit that shuts off the beam after a time depending on the beam current. | |||
{{BeginSpecs}} | |||
{{Spec | Screen size | 8 × 10 Div. @ 8.5 mm }} | |||
{{Spec | Resolution | 17 lines / Div. }} | |||
{{Spec | Vertical deflection factor | 1 V/cm }} | |||
{{Spec | Vertical deflection impedance | 200 Ω }} | |||
{{Spec | Vertical bandwidth | 2.6 GHz (3 GHz spec claimed in maintenance document linked below) }} | |||
{{Spec | Horizontal deflection factor | 2 V/Div }} | |||
{{Spec | Horizontal deflection impedance | 365 Ω }} | |||
{{Spec | Horizontal bandwidth | 1.5 GHz }} | |||
{{EndSpecs}} | |||
==Links== | ==Links== | ||