Replacement of Preselector Bandpass Filter 2FL4

TM 11-5820-695-35

(9) Install preselector bandpass filter

3-44. Replacement of Preselector Bandpass Filter

2FL4 in electrical equipment cabinet 2A15, aligning filter

2FL4 (fig. 3-17)

mounting holes with mounting holes on preselector

Removal.

support. Then secure preselector bandpass filter 2FL4

(1) Remove power from R-1467/GRC-

to preselector bracket using the two bolts and washers

144 (para 8-88a).

removed in step a(12).

(2) Loosen the two meter panel captive

NOTE

screws on meter panel assembly 2A15A2 (fig. 817).

After installing preselector bandpass

(3) Position the meter panel assembly

filter 2FL4 remove the thin sheet of

upward and lock it in position by using the panel locking

rigid material placed on top of

latch (fig. 3-19).

cabinet to support the input

(4) Loosen the four captive screws (fig.

waveguide section.

818) that secure tunnel diode amplifier 2A2 to its

(10) Secure preselector bandpass filter

mounting bracket a few turns each.

2FL4 upper flange to top of electrical equipment cabinet

(5) Disconnect the knurled connector

2A15 using the six screws removed in step a (11).

INPUT J1 on tunnel diode amplifier 2A2 from its mating

(11) Secure external input waveguide

connector on preselector bandpass filter 2FL4 by

section to preselector bandpass filter 2FL4 using the

rotating the knurled connector clockwise.

eight screws removed in step a(10).

(6) Remove eight input waveguide flange

(12) Connect the power cable 2A15W2P2

screws (fig. 3-20) securing external input waveguide

removed in a(9) above to the POWER JS connector (on

section to waveguide flange on preselector bandpass

the rear of the tunnel diode amplifier) by pushing the

filter 2FL4.

power cable connector in and rotating it 1/2-turn

NOTE

counterclockwise (as viewed from front of 2A2).

After removing the six screws (step

(13) Insert tunnel diode amplifier 2A2 into

electrical equipment cabinet 2A15 and rotate tunnel

a(7) below); obtain a thin sheet of

diode amplifier 2A2 in a counterclockwise direction until

rigid material about 1/16th inch thick

it can be slid into its mounting bracket.

and insert this material between the

top of the cabinet and the input

(14) Tighten the four captive screws on the

waveguide section to support the

tunnel diode amplifier mounting bracket until the tunnel

input waveguide section when

diode amplifier 2A2 is loosely held in position by the four

preselector bandpass filter 2FL4 is

captive screws.

being removed.

(15) Connect and hand tighten the knurled

(7) Remove six 2FL4 flange screws (fig.

connector INPUT J1 on tunnel diode amplifier 2A2 to its

3-20) securing preselector bandpass filter 2FL4 to the

mating connector on preselector bandpass filter 2FL4 by

top of electrical equipment cabinet 2A15.

rotating the knurled connector in a counterclockwise

direction.

(8) Remove two bolts and washers (fig.

818) securing lower part of preselector bandpass filter

(16) Tighten the four captive screws on the

2FL4 to electrical equipment cabinet 2A16 preselector

tunnel diode amplifier mounting bracket.

support and remove preselector bandpass filter 2FL4.

(17) Connect coaxial cable 2A15W1 to the

Replacement.

OUTPUT J2 connector on tunnel diode amplifier 2A2.

(18) Release the meter panel assembly

(1) Install preselector bandpass filter

2A15A2 and position it against the cabinet.

2FL4 in electrical equipment cabinet 2A15 aligning filter

mounting holes with mounting holes on preselector

(19) Secure

meter

panel

assembly

support. Then secure preselector bandpass filter 2FL4

2A15A2 to electrical equipment cabinet 2A15 with the

to preselector bracket using the two bolts and washers

two meter panel captive screws.

removed in step a(8).

(20) Restore power to R-1467/GRC-144

NOTE

(para 38b).

After installing preselector bandpa ss

filter 2FL4 remove the thin sheet of

rigid material placed on top of

cabinet to support the input

waveguide section.

3-69