Specifications

Section S
3F Select Board
S.1 Introduction
This section describes the 3Frequency select Board. Topics in-
clude Function and Location.
Parts list for this board is in Section VII.
Board # 843 5523 973
Schematic # 843 5523 971
PWA # 992 9764 500
S.2 Function
The 3F select board is used to select 1 of 3 predetermined
frequencies. By selecting 1 of the 3 Frequency Pushbuttons a
command will then be issued to the 3F controller (described
later). Also on this board is the current status of the Transmitters
Frequency. LED’s imbedded in the switches tell you what the
current Freq is by 3 latching relays. In the event of an AC failure
and when AC is restored the last state that the Relays were in will
represent the current state.
S.3 Location
The 3F select board is located on the Left PAC front Door. Next
to the Frequency Control Board. See View 24.
Refer to Schematic # 843 5523 973 for the following discussion.
Frequency 1 Selection. Switch # 1 is a momentary pushbutton
switch. When activated a Gnd is sent to the 3F controller. The
controller will send a Set command to K1 and a Reset command
to K2 and K3.
12/16/03 888-2339-002 S-1
WARNING: Disconnect primary power prior to servicing.