PEM FOR FILTERS, UPPER SIDEBAND (1.75 MC.) QUARTZ CRYSTALS TYPE EL-FR (X-1).
Quarterly progress rept. no. 1, 30 Jun-30 Sep 64.
SYSTEMS INC ORLANDO FLA
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The capability is to be established of manufacturing upper-sideband 1.75-mc quartz crystal filters of the type EL-FR X- that is designed to provide uppersideband selection in equipment such as the ANGRC-106. The filter 2-db bandwidth is about 3.2 kc., with carrier frequency rejection of at least 30 db and lower sideband rejection of at least 60 db. The technical requirement is specification SCS-207 which references SCL-7755. The designs considered include an 18 crystal-3 section filter, a 10 crystal-2 section filter, and a 12 crystal-6 section filter. The basis of the type I, 18-crystal design was Crystal Filters, the Final Report of Motorola, Inc., Chicago, on Contract DA-36-039-SC-85300, Aug. 15, 1963. The design of the type III, 12-crystal design, was verified experimentally it was based on the report of Smythe, The Synthesis of Crystal-Capacitor Tandem Lattice All-Pole Bandpass Filters on the Insertion Loss Basis, Proceedins of the 18th Annual Symposium on Frequency Control, USAEL, Ft. Monmouth, N. J., May 1964. Types I and III were estimated to provide better performance with less cost than type II, the 10-crystal design of Hughes Aircraft Co., SSB and VHF Crystal Filters, 3d quarterly report of Contract DA-36-039AMC-02305E, using an image parameter design described by Storch as the type NB filter in 1957, Hughes, High Frequency Crystal Filters, 2d quarterly report on Contract DA-36-SC-73070 PB-146 564.