PFN Adjustment Procedure cont'd

TM 9-1240-369-34

(b) If required, turn the azimuth control to

NOTE

reduce indication on RCVR-XMTR STATUS meter to

The R/T tester and the PFN charge

midscale.

ammeter may he used by DS level

maintenance personnel on the Sheridan

indication on the RCVR-XMTR STATUS meter. Record

vehicle as well as in the hot mockup.

setting as observed in the elevation position window on

When the R /T tester and the PFN charge

the elevation control.

ammeter are used on the Sheridan vehicle,

(d) Turn the azimuth control to the position

the vehicle must be located in an area

marked in (a) above.

which is sheltered from the weather. The

(11) Observe the indication on RCVR-XMTR

vehicle, receiver-transmitter unit and R/T

STATUS meter; the meter indicates in the white band

tester must be allowed to temperature

when the receiver sensitivity is within acceptable limits.

stabilize for 12 hours to a temperature of 75

If meter indication is below the white band, the receiver

10 F. If the R/T tester and the PFN

gain is low and the receiver-transmitter unit and the

charge ammeter are used on the Sheridan

power supply control unit must be replaced. Go to step

vehicle perform steps (1) thru (33). If the

(24).

R/T tester and the PFN charge ammeter are

NOTE

to be used in the hot mock-up. perform

If the above malfunction is observed at

steps (2) thru (32).

general support, replace the photomultiplier

(1) Remove ballistic connector cover, power supple

chassis (89, fig. 3-6) assembly and repeat

control unit cover and power supply control unit as

this procedure.

described in TM 9-2350-230-20.

(12) Set MODE SELECT switch on the R/T tester to

(2) Slide latch (1) to the left and open cover

the position that lights OFF lamp. Do not disturb the

assembly (2).

setting of the prism steering mechanism.

WARNING

(13) Set LASER MODE CONTROL switch on the

Laser light leakage due to improper

commander's control unit to OFF.

mounting may cause injury to eyes.

WARNING

Ensure that the light seal on the tester

Laser light leakage due to improper

adapter and the R/T tester are correctly

mounting may cause injury to eyes. Ensure

mated and that the screws are secured.

that the light seal on the tester adapter and

This procedure will prevent light leakage

the R/T tester are correctly mated and that

between the interface of the R/T tester, the

the screws are secured. This procedure will

receiver-transmitter unit and the tester

prevent light leakage from occurring at the

adapter.

interface of the R/T tester, the receiver-

(3) Remove three screws (3) and three washers (4)

transmitter unit, and the tester adapter.

from front of the receiver-transmitter unit.

(14) Move the R/T tester from the RCVR test position

(4) Secure tester adapter (5) to the receiver-

on the tester adapter to the XMTR TEST position.

transmitter unit with three screws (3) and three washers

(15) Set LASER MODE CONTROL switch on the

(4).

commander's control unit to ON.

(5) Secure R/T tester (6) to the tester adapter with

(16) Turn MODE SELECT switch on the R/T tester

two captive screws (7). Mount the R/T tester such that

counterclockwise to the position that lights red XMTR

RCVR TEST on the tester adapter is exposed.

indicator lamp.

(6) Connect hot mock-up as illustrated in figure 2-5.

(17) Set RESET-FIRE switch on the R/T tester to

(7) Set power supply control unit to 24 nominal.

RESET and release.

(8) Set LASER MODE CONTROL switch on the

(18) Pull out and set RESET-FIRE switch on the R/T

commander's control unit to ON.

tester to FIRE and release.

(9) Turn MODE SELECT switch on the R/T tester

(19) Observe the indication on RCVR-XMTR

clockwise to the position that lights white RCVR indicator

STATUS meter; meter indicates in the red band when

lamp.

the transmitter output energy is within acceptable limits.

(10) Adjust the prism steering mechanism the

Press PFN charge ammeter PRESS TO TEST switch.

azimuth and elevation controls on the R/T control unit) to

The maximum indication should be no more than 82

achieve maximum signal output on RCVR-XMTR

microamps. If the indication is not in the red band,

STATUS meter as follows:

remove PFN ADJ screw (1A, fig. 3-2) (permits access to

(a) Adjust the azimuth control to obtain peak

indication on the R/T tester RCVR-XMTR STATUS

meter. Record setting as observed in the azimuth

position window on the azimuth control.

2-10