Diodemodtager: Forskelle mellem versioner

[[Fil:Corn cob pipe catwhisker radio 1922.png|thumb|Et tidligt bærbart krystalapparat med [[krystaldetektor]] og [[rammeantenne]]. Ifølge teksten kunne krystalapparatet modtage signaler op til ca. 16 km fra en [[radiostation]].]]

'''Krystalmodtagere''' (også kendt som '''krystalapparater''', '''krystalradioer''') blev først bygget omkring [[1900]] af [[Greenleaf Whittier Pickard]].<ref name="GWP">[https://www.americanradiohistory.com/Archive-Electrical-Experimenter/EE-1919-08.pdf G. W. Pickard, "How I Invented the Crystal Detector". ''Electrical Experimenter'', vol. VII, no. 4, p. 325, Aug. 1919] Citat: "...In 1898, when my work in Radio-communication began, there was but one detector—the [[Kohærer|coherer]]...In the period 1902 to 1906, I tested many different minerals and combinations, including magnetite, pyrite, galena, molybdenite, silicon and zincite. Much development was also required on holders for these minerals...31,250 Crystal Detectors Invented. A list of the several thousand materials I have tested would make dry reading. Suffice it to say that I have found some tzvo hundred and fifty minerals and furnace products which make operative detectors, cither against metallic contacts, or in combination with other minerals. The possible combinations of these two hundred and fifty substances amounting to some 31,250, pairs, have all been tested by me, or by my assistants, and many hundred useful pairs have been found...", [https://web.archive.org/web/20220707212053/https://worldradiohistory.com/Archive-Electrical-Experimenter/EE-1919-08.pdf backup]</ref> Krystalmodtagerne anvendte [[krystaldetektor]]dioder til at detektere [[radiofoni]]signaler. Andre ensrettende overgange blev lavet af oxiderede metal[[legering]]er.

 

=== Opbygning ===

 

Antennen er tilsluttet til [[Elektrisk svingningskreds|svingningskredsens]] ene ende direkte, via en [[elektrisk kondensator|kondensator]] eller på et udtag på spolen – og jordlederen er forbundet til den anden svingningskreds ende.<ref name="crystal-radio-set">God beskrivelse på engelsk: [http://www.electronics-tutorials.com/receivers/crystal-radio-set.htm#top electronics-tutorials.com: Crystal Radio set] {{Webarchive|url=https://web.archive.org/web/20040914084304/http://www.electronics-tutorials.com/receivers/crystal-radio-set.htm#top |date=14. september 2004 }}</ref><ref name="Gonzo">{{Cite book | last = Field | first = Simon Quellen | title = Gonzo gizmos: Projects and devices to channel your inner geek | publisher = Chicago Review Press | year = 2003 | location = US | page = 85 | url = https://books.google.com/books?id=t-N1KdTb0FwC&pg=PT97 | isbn = 978-1-55652-520-9 }}</ref>