Sharp R-309B Instrucciones de operaciones descargar pdf (Pagina 43)

b.

Since

it

is

ess

entia l th

at

the

fixed

attenuation

is

precisely

20

dB,

the

checks

listed

in

Table

5-5

must

be

performed

if

damage

is

suspected.

c.

When

it

becomes

necessary

to

repair

the

fixed

attenuator,

re-

move

the

single

screw

and

slide

the

cover

off.

A

decal

on

the

side

of

the

fixed

attenuator

casting

shows

the

component

values.

The

resis-

tors

are

standard

5

percent

values.

The

fuse

is

a

special

RF

fuse

(Buss-

man

tfG FA

1/

32A ) .

Test

Equipment

Required:

a.

Signal

Generator,

Hewlett-

Packard

Model

60S.

b.

Metered

receiver

with

50Q

input

impedances

capable

of

operating

at

the

required

frequencies.

c.

RF

Voltmeter,

Boonton

Model

9lD,

or

equivalent.

5.4.5

Signal.Generation-Output

Level

Adjustment

Preli

min

ary

Instructions:

a.

The

output

levels

are

adjusted

by

signal

sub

stitution

.

Refer

to

Table

5-6

.

First,

a

signal

from

a

cali-

brated

source

is

fed

into

a

metered

receiver

and

the

meter

reading

noted.

The

CE-7

is

then

substituted

for

the

calibrated

source

and

the

output

LEVEL

SET

control

of

the

CE-7

is

a

djusted

until

the

meter

reads

the

same

as

before.

The

receiver

should

be

metered

at

a

point

where

saturation

is

least

__

likely

to

occur

(for

example,

the

first

and

second

IF

stage)

and

the

HF

input

signal

should

be

preferably

1.

0

microvolt.

b.

Select

a

frequency

at

which

the

adjustment

is

to

be

made.

This

frequency

must

be

within

the

cap-

..

abilities

of

the

external

receiver,

the

external

signal

generator,

and

c .

set

the

signal

gcnc

rnto

r to thi s

frequency

by

morutortnc

it

on

the

CE-7.

. b

NOTE

When

using

frequcn

cics

hig-her

than

100 MHz,

the

signal

gcncruto

r

must

be

tuned

very

slowly

to ac-

commodate

the

narrow

bandwidth

of

the

CE-7.

If

a

Pr

es clccto r is

being

used,

ensure

that

it

s

SE LE

CTIVITY

switch

is

set

to

l'\ORl\IAL.

Test

Equipment

Required:

a. Signal

Generator,

Hewlett-

Packard

Model

6OS.

b.

Metered

receiver

with

50Q

input

impedances

capable

of

operating

at

the

required

frequencies

.

5.4.6

Slgnal-Cenerator

-vllxer

Input

Level

Check

Preliminar

y

Instructions:

a.

The

signal

generator

mixer

may

be

damaged

in

the

same

manner

as

noted

for

the

20-dB

fixed

attenuator

(Para-

graph

5.4

.4)

. When

it

becomes

nec-

essary

to

repair

the

signal

generator

mixer,

it

will

also

be

necessary

to

readjust

the

signal

generator

output

lev

el s

(Table

5

-6).

b.

The

two

inputs

to

the

signal

generator

mixer

are:

a

10-MHz

signal

from

the

Multi

-Os

cillator

via

the

Signal

Genera-

tor

Step

Attenuator,

and

a

signal

that

may

contain

frequencies

of

from

28 )'IHz to 1150 MHz

from

the

Har-

monic

Generator

via

the

coaxial

relay.

Refer

to

Table

5-7

.

Test

Equipment

Required:

the

CE-7

.

RF

Voltmeter,

Boonton

Model

9lD

.

•

5-11

560

1"

0 0

15

"1

1 2 ... 38 39 40 41 42 43 44 45 46 47 48 ... 95 96

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