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dc.contributor.authorHedeman, W. R., Jr.
dc.contributor.authorNichols, M. H.
dc.date.accessioned2016-04-25T17:02:17Zen
dc.date.available2016-04-25T17:02:17Zen
dc.date.issued1971-09en
dc.identifier.issn0884-5123en
dc.identifier.issn0074-9079en
dc.identifier.urihttp://hdl.handle.net/10150/607032en
dc.descriptionInternational Telemetering Conference Proceedings / September 27-29, 1971 / Washington Hilton Hotel, Washington, D.C.en_US
dc.description.abstractIn a previous paper (1) the authors reported notch noise loading tests of baseband (post-detection) tape recording showing dependency of the notch noise power ratio, NPR, on record level. The purpose of this paper is to report notch noise loading tests on pre-detection tape recording showing NPR dependence on record level, bias level, and output equalization. Both the baseband and pre-detection recording tests were made with the Hewlett-Packard Model 3950 recorder/reproducer. Generally, the pre-detection NPR were 5db or more improved over the baseband NPR. The extent of the improvement depends, in part, on the quality of the vco and discriminators utilized for the pre-detection recording as well as the carrier deviation. As the linearity of the vco and discriminator and the phase linearity of the circuits that pass the pre-detection signal are improved, the limiting factor in NPR is the noise added by the reproduce amplifier. Increasing the record level above IRIG standard produces an improvement in the output signal-to-noise ratio, NPRO, of 3 to 5 db using IRIG standard bias. Eliminating the bias and recording at the level which results in maximum output of the fundamental produced up to 8 db improvement in NPRO over IRIG. In the course of the tests it was discovered that if harmonics are present in the recorded pre-detection signal and/or are generated in the record/reproduce process, serious intermodulation can occur unless a low-pass filter ahead of the discriminator is used.
dc.description.sponsorshipInternational Foundation for Telemeteringen
dc.language.isoen_USen
dc.publisherInternational Foundation for Telemeteringen
dc.relation.urlhttp://www.telemetry.org/en
dc.rightsCopyright © International Foundation for Telemeteringen
dc.titleNotch Noise Loading Date on Pre-Detection Recording of FM Carriersen_US
dc.typetexten
dc.typeProceedingsen
dc.contributor.departmentAerospace Corporationen
dc.identifier.journalInternational Telemetering Conference Proceedingsen
dc.description.collectioninformationProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection.en
refterms.dateFOA2018-06-24T15:47:53Z
html.description.abstractIn a previous paper (1) the authors reported notch noise loading tests of baseband (post-detection) tape recording showing dependency of the notch noise power ratio, NPR, on record level. The purpose of this paper is to report notch noise loading tests on pre-detection tape recording showing NPR dependence on record level, bias level, and output equalization. Both the baseband and pre-detection recording tests were made with the Hewlett-Packard Model 3950 recorder/reproducer. Generally, the pre-detection NPR were 5db or more improved over the baseband NPR. The extent of the improvement depends, in part, on the quality of the vco and discriminators utilized for the pre-detection recording as well as the carrier deviation. As the linearity of the vco and discriminator and the phase linearity of the circuits that pass the pre-detection signal are improved, the limiting factor in NPR is the noise added by the reproduce amplifier. Increasing the record level above IRIG standard produces an improvement in the output signal-to-noise ratio, NPRO, of 3 to 5 db using IRIG standard bias. Eliminating the bias and recording at the level which results in maximum output of the fundamental produced up to 8 db improvement in NPRO over IRIG. In the course of the tests it was discovered that if harmonics are present in the recorded pre-detection signal and/or are generated in the record/reproduce process, serious intermodulation can occur unless a low-pass filter ahead of the discriminator is used.


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