37,092
edits
No edit summary |
No edit summary |
||
(10 intermediate revisions by 3 users not shown) | |||
Line 1: | Line 1: | ||
{{CRT | |||
It features a [[ | |Manufacturer=Tektronix | ||
|Model=T7100 | |||
|Part_nos=154-0783-00 | |||
|Description=[[micro-channel plate CRT]] | |||
|Used_in=7104; R7103 | |||
|Designers=Dennis Hall;Aris Silzars;Conrad Odenthal | |||
}} used in the [[7104]] and [[R7103]] analog 1 GHz scopes. | |||
It features a [[micro-channel plate]] electron beam amplification stage. | |||
[[File:Micro-channel plate diagram.jpg | thumb | 550px | right | MCP diagram<br />(click image to enlarge)]] | [[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 amplifier bandwidth. | ||
to achieve high deflection sensitivity, eliminating the need for high amplifier output voltages, thereby boosting | |||
amplifier bandwidth. | |||
The electron beam passes through terminated helical deflection plates (both X and Y axes use | The electron beam passes through terminated helical deflection plates (both X and Y axes use this form of [[distributed deflection plates]] to achieve the necessary bandwidth), followed by an electrostatic scan-expansion lens that increases deflection 4.5 times vertically and 4 times horizontally, before it hits the micro-channel plate (MCP). | ||
this form of [[distributed deflection plates]] to achieve the necessary bandwidth), followed by | |||
an electrostatic scan-expansion lens that increases deflection 4.5 times vertically and 4 times | |||
horizontally, before it hits the micro-channel plate (MCP). | |||
The deflection structures are described in [https://patents.google.com/patent/US4093891 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 53−55 | The scan-expansion lens is a "box lens" design, which is discussed on pages 53−55 of the ''[[Media:7104_maintenance.pdf|7104 maintenance document]]''. | ||
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. | ||
The inside walls of these channels are coated with resistive material, with a voltage of 700-1050 V applied | The inside walls of these channels are coated with resistive material, with a voltage of 700-1050 V applied between back and front of the plate. Electrons entering a channel hit the wall where they initiate a cascade of secondary electron emission like in a [https://en.wikipedia.org/wiki/Photomultiplier photomultiplier]. | ||
between back and front of the plate. Electrons entering a channel hit the wall where they initiate a cascade | |||
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. | ||
Line 42: | Line 42: | ||
* [[Media:7104_maintenance.pdf|7104 maintenance document]], p.30+ | * [[Media:7104_maintenance.pdf|7104 maintenance document]], p.30+ | ||
* [[T7101]] | * [[T7101]] | ||
* [[Patent US 4142128A|US Patent 4142128A – Box-shaped scan expansion lens for cathode ray tube]] ([[Conrad Odenthal]]) | |||
* [[Conrad Odenthal]], ''[[Media:Conrad Odenthal - A box-shaped scan expansion lens for an oscilloscope CRT.pdf|A box-shaped scan expansion lens for an oscilloscope CRT]] (1977) | |||
* [[Media:Box lens design being tried by Tektronix in experimental CRTs.pdf|Box lens design being tried by Tektronix in experimental CRTs]] (1977) | |||
==Pictures== | ==Pictures== | ||
Line 58: | Line 61: | ||
Tek7104-200ps-singleshot.jpg | 7104 recording a single shot pulse (from [[067-0587-02]]) at 200 ps/Div. Camera: Nikon D7000, 50 mm f/1.4, ISO 3200, 1/2 s. CRT filter not removed. | Tek7104-200ps-singleshot.jpg | 7104 recording a single shot pulse (from [[067-0587-02]]) at 200 ps/Div. Camera: Nikon D7000, 50 mm f/1.4, ISO 3200, 1/2 s. CRT filter not removed. | ||
Tek7104-200ps-singleshot-sin1-1g.jpg | 7104 recording 1 GHz sine, single shot at 500 ps/Div. Camera: Nikon D7000, 50 mm f/1.4, ISO 3200, 1/2 s. CRT filter not removed. CRT amplification loss is evident around the center line. | Tek7104-200ps-singleshot-sin1-1g.jpg | 7104 recording 1 GHz sine, single shot at 500 ps/Div. Camera: Nikon D7000, 50 mm f/1.4, ISO 3200, 1/2 s. CRT filter not removed. CRT amplification loss is evident around the center line. | ||
Tek t7100 lens structure.jpg | |||
</gallery> | </gallery> | ||
[[Category:Micro-channel plate CRTs]] | [[Category:Micro-channel plate CRTs]] |