Characteristics and Use of Laboratory Test Equipment, and Special Tools Required for Alignment

ricated cable assembly consists of a 4-foot

82. Characteristics and Use of Laboratory

l e n g t h of RG-55/U cable terminated by a

Test Equipment, and Special Tools

UG-88/U connector, BNC-type, and an mb-

Required for Alignment

s e r i e s type 45000 connector. This cable

The type of laboratory test equipment

is used in aligning the tuning unit 2 and 4

a n d the special tools required for align-

i f . amplifiers.

ment of the various tuning units are indi-

h. UG-88/U Plug. This male-type BNC-

cated in a through k b e l o w .

s e r i e s connector terminates the RG-55/U

a . Tuning Unit 1 Signal Generator. A

c o a x i a l cable.

i. Mb-Series Type 45000 Connector.

c w signal generator is required that can

produce output within the frequency range

T h i s female minature bayonet series con-

f r o m 150 kc to 30 mc at an accuracy of

nector terminates the RG-55/U coaxial

+ 1 percent. An output voltage from 0.05

cable.

microvolt to 100 millivolts must be avail-

j . Tuning Wand. T h i s i s a 6 - i n c h b y

able. The output impedance at the attenua-

7 / 3 2 - i n c h tuning wand used for adjusting

tor jack must be 50 ohms. This impedance

the coils (tuning unit 2) and variable

is obtained when the type 1OOO-P2 40-ohm

capacitors (tuning unit 3).

series unit (supplied with this signal gen-

k. Soldering Aid Tool. The soldering aid

erator) is inserted into the attenuator out-

i s used for beiding the split rotor blades

put jack.

of the tuning capacitors during the align-

b. Tuning Unit 4 Signal Generator. A cw

m e n t of the rf sections of tuning units 3

s i g n a l generator is required that can pro-

and 4.

d u c e output within the frequency range

f r o m 400 to 1,000 mc at an accuracy of

83. Filament-Voltage and 400 -VoIt

0 . 5 percent. An output voltage must be

Adjustments

a v a i l a b l e which is continuously variable

from 0.1 microvolt to approximately 1 volt,

Remove the main unit from its instrument

case (para 40b, item 12, TM 11-6625-351-

across a 50 ohm load.

12) and make the following adjustments in

c. Tuning Unit 4 Wavemeter. A w a v e -

the power supply section of the main unit

meter is required for checking the operat-

before proceeding with the alignment.

ing frequency of the rf amplifier and oscil-

l a t o r in the 700-1,000-mc band of tuning

a. 420-Volt Adjustment.

(1) S e t POLARITY switch S709 at +.

u n i t 4. This wave meter covers the fre-

This switch is accessible from the

quency range from 250 to 1,250 mc and is

a c c u r a t e to within 2 percent of its dial

top of the main unit adjacent to the

voltage regulator assembly

frequency.

(fig. 52) .

d. Dc Vtvm. This is a vacuum tube volt-

meter (vtvm) capable of measuring ac and

(2) C o n n e c t the positive lead of the

m u l t i m e t e r to the top right termi-

dc voltages from 0 to 1,500 volts and re-

sistance from 0.2 ohm to 1,000 megohms.

nal (1) of toggle switch S709 (fig.

It has a dc input resistance of 11 megohms.

52). Connect the negative lead of the

m u l t i m e t e r to chassis ground. Set

e. Type 472S0 Adapter. This is an adap-

ter for converting a UG88/U connector to

t h e multimeter FUNCTION switch

a n md (minature bayonet) Industrial Pro-

to the DIRECT position.

ducts Co. type 45000 connector, and is re-

(3) Set the main unit POWER switch at

ON.

quired in aligning tuning unit 1 if. ampli-

fier.

(4) I M P U L S E G E N L E V E L S E T

control R762 is a dual potentiom-

f. UG-201A/U Adapter. This is an

a d a p t e r for connecting the UG-88/U con-

eter which is mounted directly be-

nector to the N-series SIGNAL INPUT jack

neath POLARITY switch S709 (fig.

52) on the partition which separates

on the main unit front panel. It is required

i n aligning the tuning unit 1 rf tuner.

the power supply from the bottom

deck of the main chassis. Vary the

g. Fabricated Cable Assembly. The fab-

191