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The model 5302 telephone was introduced about 1955 by Western Electric as a look-alike product to the model 500 telephone to meet the increasing post-World War II demand for a modernized telephone, while reusing existing component supplies from the older model 302 telephone. The 302 had been issued since 1936, but starting in 1950, units were replaced with the new 500 series sets, without having served their useful component life. The 5300 and 5400 series of telephones consisted of the 300-series and the 400-series models converted to approach the appearance and performance of the model 500.〔Bell System Practices C32.569, Issue 1, May 1956〕 This was accomplished with a new housing, new number ring and dial plate, and a ringer volume control that could be adjusted by users. The model numbering for these sets was derived from the converted 300 or 400 series units by prefixing those model numbers with the digit 5. In addition to the model 5302, the series also consisted of the models 5304, 5306, and 5410 telephone sets. ==Design== Conceived years after the 1949 introduction of the Model 500, the model 5302 telephone was a design adaptation from the pre-WWII era model 302 to the 500-series desk top telephones. It was introduced to reuse the existing large stock of parts from the 302 model in the refurbishing plants as those were replaced with 500 series sets, while still providing the modern style elements of the 500 telephone. The 5302 essentially was a 302 telephone under a new cover. The new shell design was based on the 500 design and accommodated the front-to-back shorter model 302 base. As the model 302 had the dial and hook switch mounted on the phone shell, the 5302 accommodated that design, in contrast to the model 500, which had all components mounted on the phone base. Like the 500, the dial also displayed the numbers and letters on the outside of the finger dial, however, the dial itself was actually the smaller 5H dial from the model 302, relabeled as 5M, or one of newer 6-series dials (6H). The cradle can accommodate the earlier F1 handset from the 302 or the newer, wider G-type of the 500. A special G-type handset, commonly referred to as GF but labeled G1, produced for the Model 5302 consisted of Bakelite and was completed by August 1955. It used an F1 transmitter and contained a plastic insert to allow for the use of an HA receiver, as in the 302. The use of the old transmitter and receiver avoided elevating sidetone on short loops as was the result with the more efficient G handset when used without equalization circuitry. When issued with the G1 handset, as in the 500 model phone, the handset contained U1 and T1 elements. The majority of model 5302 telephones had the original F1 handset and were preferentially installed in areas near the central offices, while the set with the G1 handset could be deployed on long loops because of better gain characteristics of the handset. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「model 5302 telephone」の詳細全文を読む スポンサード リンク
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