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General => General Technical Chat => Topic started by: Homer J Simpson on September 12, 2016, 02:22:39 am

Title: Crystals 1958 Alan Holden - Bell Laboratories
Post by: Homer J Simpson on September 12, 2016, 02:22:39 am

https://www.youtube.com/watch?v=_YW0wjYdUPw (https://www.youtube.com/watch?v=_YW0wjYdUPw)

Title: Re: Crystals 1958 Alan Holden - Bell Laboratories
Post by: T3sl4co1l on September 12, 2016, 08:38:30 am

Relevant:
http://www.ieee-uffc.org/main/history-bottom.asp (http://www.ieee-uffc.org/main/history-bottom.asp)

On a related note, I recently happened upon an antique crystal.  "100kc", in a crimped metal can with two pins (much as electrolytic capacitors were made, back then), by James Knights Co. (now CTS), dated 10-58 I think.  Quite low ESR, for a 100kHz crystal: about 800 ohms.  The wafer itself is likely quite large.  I can feel it bouncing around on the supports when I tap the can.  The bandwidth is extremely narrow, less than I can effectively measure with an analog function generator and DSO -- maybe 50Hz!

Tim

Title: Re: Crystals 1958 Alan Holden - Bell Laboratories
Post by: setq on September 12, 2016, 10:57:37 am

Thanks for this. I absolutely love these.

Title: Re: Crystals 1958 Alan Holden - Bell Laboratories
Post by: VK3DRB on September 12, 2016, 11:52:55 am

Fascinating. Alan Holden was indeed passionate about crystals.

http://www.nytimes.com/1985/08/23/nyregion/alan-holden-who-assisted-on-sonar-project-dies-at-81.html (http://www.nytimes.com/1985/08/23/nyregion/alan-holden-who-assisted-on-sonar-project-dies-at-81.html)