2,344
edits
No edit summary |
No edit summary |
||
Line 1: | Line 1: | ||
[[File:GR-874 connector 1.jpg|250px|thumb|right]] | [[File:GR-874 connector 1.jpg|250px|thumb|right]] | ||
'''General Radio 874 (GR-874)''' connectors are hermaphroditic (asexual) coaxial RF connectors developed by [[Eduard Karplus]] in the late 1940s, initially for applications up to "4500 Mc" (4.5 GHz). | '''General Radio 874 (GR-874)''' connectors are hermaphroditic (asexual) coaxial RF connectors developed by [[Eduard Karplus]], [[Harold Wilson]] and others in the late 1940s, initially for applications up to "4500 Mc" (4.5 GHz). | ||
GR-874 connectors are carefully engineered to keep a constant impedance throughout the signal path, by varying connector diameters between free-air and dielectrically supported sections. These connectors therefore exhibit very little reflection and are well suited for frequencies up to 9 GHz and pulse applications. For higher frequencies a smaller connector is required to avoid the excitation of wave guide modes. | GR-874 connectors are carefully engineered to keep a constant impedance throughout the signal path, by varying connector diameters between free-air and dielectrically supported sections. These connectors therefore exhibit very little reflection and are well suited for frequencies up to 9 GHz and pulse applications. For higher frequencies a smaller connector is required to avoid the excitation of wave guide modes. | ||
Most GR-874 connectors came in 50 Ω impedance. Versions for 75 Ω and 125 Ω were also available using the same ground shield and housing, but different (thinner) center pin geometry. See for example the [ | Most GR-874 connectors came in 50 Ω impedance. Versions for 75 Ω and 125 Ω were also available using the same ground shield and housing, but different (thinner) center pin geometry. See for example the [[tekwiki:519|Tektronix 519 oscilloscope]] that had a 125 Ω GR-874 variant at the input. | ||
Different versions of the connector have different maximum voltage ratings; 1000 V is typical. There are locking and non-locking versions. | Different versions of the connector have different maximum voltage ratings; 1000 V is typical. There are locking and non-locking versions. | ||
Line 12: | Line 12: | ||
GR-874 connectors and adapters continue to be available through [http://www.ietlabs.com/gr874-connectors.html IET Labs], [http://www.mgs4u.com/RF-Microwave/General-Radio-GR-874.htm Max-Gain Systems], [https://www.pasternack.com/gr874-adapters-category.aspx Pasternack] and possibly others. | GR-874 connectors and adapters continue to be available through [http://www.ietlabs.com/gr874-connectors.html IET Labs], [http://www.mgs4u.com/RF-Microwave/General-Radio-GR-874.htm Max-Gain Systems], [https://www.pasternack.com/gr874-adapters-category.aspx Pasternack] and possibly others. | ||
The connector was also used by other manufacturers in the 1960s and 1970s, e.g. Tektronix (see | The connector was also used by other manufacturers in the 1960s and 1970s, e.g. Tektronix (see [[tekwiki:GR-874 connector]]), Hewlett-Packard, and Philips. | ||
==Links== | ==Links== |