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Folder 991 Division (8 Digits Series)

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pdf 991.006.01 I1-se Popular

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991.006.01_I1-se.pdf

991.006.01 I1-se

PBX Systems - Range Chart - Trunk and Station Conductor Loop
Ranges for PBXs Connected To No. 1 Crossbar Central Offices Having
1300-Ohm Subscriber Conductor Loop - 400-Ohm Talking Battery Feed
Circuit - AC-DC or Superimposed Ringing (84-88V AC Component) - Office
Voltage of 48V (Floating), Issue 1, 1960-03-01

pdf 991.006.04 I1-se Popular

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991.006.04_I1-se.pdf

991.006.04 I1-se

PBX Systems - Range Chart - Trunk and Station Conductor Loop
Ranges for PBXs Connected To Panel Central Offices Having 635-Ohm
Subscriber Conductor Loop - 50-Ohm Talking Battery Feed Circuit - AC-DC
or Superimposed Ringing (72, 80, or 84 Volts Minimum AC Component) -
Minimum Office Voltage of 21V (Floating), Issue 1, 1960-05-01

pdf 991.102.02-se Popular

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991.102.02-se.pdf

991.102.02-se

608A Private Branch Exchange - General Description, Issue 1,
Feb. 1960 (Caution: 5MB due to photos)

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