Sharp R-309B Instruções de Operação descarregar pdf (Página 17)

3.40

Operating

Procedures

3.4.1

Frequency

and

Deviation

'Ieasuremenl

It

is

assumed

that

the

CE-7

is

equipped

with

a Model 303

Broadband

Xlixer

and

either

the

Model 301

Oscilloscope

or

the

Model 302

FM

Deviation

Meter

.

For

measurement

of

frequency

and

deviation

with

one

of

the

RF

Preselectors

in

-stead

of

the

Model 303,

the

same

procedure

is

followed

except

that

the

preselector

frequency

dial

must

be

set

to

the

frequency

selected

with

the

CARRIER

'FREQUENCY

SELECTOR.

a.

Connect

the

telescoping

antenna,

an

external

antenna,

0 r

other

signal

source

to

the

ANT.

connector

on

the

Broadband

Mixer

or

Preselector.

If

the

telescoping

antenna

is

used,

ex-

tend

it

to

its

full

length

for

meas-

urements

of

signals

below

30 MHz

to

approximately

18

inches

for

VHF

measurements;

use

minimum

length

for

UHF

measurements.

b.

Select

the

desired

carrier

frequency

with

the

CARRIER

FREQUENCY

SELECTOR.

c.

Place

the

function

switch

in

the

HARM.

AMP.

TUNIKGpositionand

adjust

the

HARM.

AMP.

TUNIKGcontrolforamaxi-

mum

reading

on

the

FREQCENCY

meter.

The

HARM.

A:'IP.

TCNING

control

should

indicate

the

appropriate

number

recorded

on

the

Channel

Frequency

Chart.

d.

Turn

the

function

switch

to

CAL.

/

C\\'.

The

SIG::\AL

LEVEL

lamp

should

light.

e.

Adjust

the

inner

red

knob

(concen-

tric

with

the

function

switch)

for

a

zero

(mid-scale)

reading

on

the

FREQUENCY

meter.

f. If

the

Model 301

Oscilloscope

is

being

used,

set

the

toggle

switches

for

horizontal

and

vertical

inputs

to

the

INT.

positions

and

adjust

the

VERT.

POS.

control

so

that

the

trace

is

on

the

zero

reference

line

while

the

deviation

range

switch

is

in

the

±l.;)

position.

Adjust

the

scope

INTEKSITY,

FOCUS, and

ASTIGrvIATIS:'I

controls

for

a

sharp

trace

on

the

screen.

3-5

5601"0015"1

g.

Set

the

function

switch

to

the

FREQ.-

DEV.

MEASURE

position.

[:~~~!~~~]

The

signal

level

applied

to

the

ANT.

connector

should

not

ex-

ceed

5

milliwatts

or

the

plug-in

may

be

damaged.

h. Key

the

transmitter

or

other

signal

source

to be

monitored.

The

SIG-

NAL

LEVEL

lamp

should

come

on.

If

it

does

not,

increase

the

signal

level

at

the

ANT.

connector.

Nor-

mally,

if

the

telescoping

antenna

is

used,

measurements

can

be

made

easily

when

the

CE-7

is

between

25

to

50

feet

from

the

radiating

antenna.

When

a

plug-in

prese-

lector

is

being

used,

measurements

can

be

made

at

distances

up

to

50

miles

from

the

transmitter

if

an

adequate

external

antenna

is

used.

i ,

The

difference

between

the

measured

signal

frequency

and

the

CE-7

carrier

frequency

is

indicated

on

the

FRE-

QUENCY

meter

according

to

the

posi-

tion

of

the

±kHz

(FREQUENCY

lever).

j.

Modulate

the

transmitter

or

other

signal

source

to

be

monitored

when

FM

deviation

is

to

be

measured.

Select

the

appropriate

full-scale

sensitivity

with

the

range

switch

(kHz)

on

the

deviation

plug-in

being

used.

When

the

oscilloscope

is

used,

positive

modulation

peaks

appear

above

and

negative

peaks

below

the

zero

reference

line;

the

FM

deviation

meter

will

indi-

cate

either

positive

or

negative

peaks

depending

on

the

setting

of

the

FM

DEV.

PEAKS

switch.

If

the

DEVIA

TION

PEAKS

indicator

on

the

FM

Deviation

Meter

has

been

calibrated

(see

Model

302

FM

Deviation

Meter

equipment

manual)

all

modulation

peaks

which

exceed

a

preset

level

will

cause

this

indi-

cator

to

light.

The

accuracy

of

deviation

measurement

may

be

affected

by

the

position

of

the

SELECTIVITY

switch

on

the

Broadband

Mixer

or

Preselector.

(Refer

to

the

applicable

plug-in

operating

instructions.

)

1 2 ... 12 13 14 15 16 17 18 19 20 21 22 ... 95 96

Comentários a estes Manuais

Sem comentários