STARTING PROGRAM CLOCKS

TM 11-5820-917-13

d. When the next regularly programmed sweep of the RCS-4B starts for that

transmitter, fine adjust the RCS-4B sweep and time synchronization by means of the

AUTO SYNC and/or MANUAL SLIP procedure until the receiver detects the transmitted

signal and the received signal is properly displayed on the RCS-4B CRT display.

Because in the normal programmer mode, the RCS-4B displays path 1 time only, care

should be used in setting the path 1 clock as the basic clock for all transmitters. All

transmitter start times should be set relative to the path 1 clock. It is recommended

that, if only one or two transmitters are to be received, they be synchronized with

the path 2 and/or path 3 clocks using the path 1 clock as a baseline time reference.

International time standards (e.g. WWV) time reports given every minute or by inter-

national shortwave broadcast stations (e.g. BBC) or synchronized wrist watches

(preferably electronic digital watches) can be used. Then, the path 2 and path 3

clocks are set relative to path 1 time. Another method is by voice contact between

the transmitter and receiver operators via telephone or on a prearranged frequency

using HF radio.

3-12. STARTING PROGRAM CLOCKS. To set the RCS-4B path programmer and

associated clock timers follow steps a through i below. To set the clocks with large

time offsets, refer to paragraph 3-13. To set path clocks 2 and 3 relative to path 1

timing refer to paragraph 3-14 for additional information.

Place MODE switch in MAN and press RESET.

Receiver frequency is set to 2.00

MHz

b. Place MODE switch in the SET 1 position or for the path clock that is to be

synchronized. Press RESET. Time is set at 00:00.

c. Turn all PATH PROGRAMMER thumbwheel switches to the appropriate path

number(s) for each 5 minute segment of the hour.

d. Set the ANTENNA SELECT thumbwheel switches for the appropriate antennas

connected to the receiver (refer to 3-7, step d) .

Set the FREQ range switch to appropriate 2-16 or 2-30 MHz position.

Establish clock start time relative to an external time reference (or to path

(Path 1 time can be made to appear on the

digital display by pressing the DISPLAY TIME PATH 1 pushbutton when the MODE

switch is in SET 2 or SET 3 position.)

At appropriate start time press START. The path clock starts and, if the 00

MINUTE-PATH PROGRAMMER thumbwheel switch has been set to the same path

number, the receiver sweep starts.

h. Check the accuracy of receiver clocks to time reference by observing LED

clock timer display. It is desirable for the receiver clock to be set to the time

is greater than 0.5 seconds, place the MANUAL SYNC-SLIP RATE control to 50 ms/see

and momentarily push the MANUAL SYNC toggle switch to ADV to speed up the

receiver clock, or to RET to slow down the receiver clock relative to the time reference.

Pressing the ADV/RET toggle one way for 10 seconds will change the receiver clock

by 0.5 seconds from its previous timing.