Operating instructions

ManualsBrandsSharp ManualsMicrowave OvenR-309B

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-SECOND

:;;E:-

-

-,

f - -

~QUEtIC~;-;;-ETECTOO-

-

-Il

I I

10

~Z

FROM MODEL

303

1

100

KHZ I

BROADBAND

MIXER OR

ONE

SHOT LOIIPASS

FILTER

MODE

L

30~.

305.

30bB MOLTIVIBRATOR AND BRIDGEI I

PRESELECTOO

I I

I I

T

O~

I

IEN,<5LE

GR

OUND

q.q

~Z

FROM I

q.q

~Z

I

TO SIGNAL

MUL

TI-

OSCILLATOR

Al'IPLIFIER

I I

LEVEL

TO

MaDEL 302

FM

DEVIATI

ON METER

OSCI LLOSCOPE

20 KHZ

LOIIPASS

FILTER

SWITCH

SCH~lIn

TRIGGER

I

I

OR MODEL 301

1.0

V DC FROM

SQUELCH DETECTOR IN

BROADBAND

~II

XER

OR PRESELECTOR

Figure

4-2.

Second

IF

and

Discriminator

Board,

Block

Diagram

longer

period

than

it

is

on.

The

resulting

rectangular

waveshape

at

the

collector

of

Q4

will

be

high

for

a

time

longer

or

shorter

than

10

microseconds

and

the

waveshape

at

Q5

will

be

correspondingly

low.

These

push-pull

signals

are

filtered

and

turned

into

unbalanced

de

signals

at

the

bridge

output.

The

FREQUENCY

meter

is

then

driven

negative

or

positive

depending

on

the

magnitude

and

the

direction

of

the

error.

The

output

of

the

multivibrator

is

taken

from

the

collector

of

Q5

and

is

fed to

the

base

of

emitter

follower

Q9. Q9

drives

the

20-kHz

lowpass

filter

which

removes

the

100 kHz

content.

The

output

of

the

20-kHz

lowpass

filter

consists

of

the

average

de

value

of

.the

square

wave

at

the

collector

of

Q5

with

no

modulation.

This

value

is

3.2

vdc

with

the

FREQUENCY

meter

at

zero.

See

Figure

4-4,

detail

A.

During

the

positive

cycle

of

modulation,

the

5-microsecond

pulse

at

the

collector

of

Q5

occurs

at

shorter

intervals.

Therefore,

the

voltage

at

the

output

of

the

20-kHz

lowpass

filter

4-5

5601"0015"1

+20V

R29

FP-Rl-l

lK

100 I

CAL

I

R22

IOUTPUTl

lK

x

L7

LB

Y

C23< 1

3:

1)

~---.J'YYY"\...~

~~~

T

C25

~

.05

I

FREOUENCY

I _

.05

R23

R31

357

27't

COO\L

1~~

----

---

--

--

---

--

--

--

--

--

-E-}-

~~LL

-

-=

~

lin=100

KHZ

fin=100

KHZ

f;~;lOO

KHZ

INPUT

TRIGGER

(O't BASE)

LJ....lJ

" I I I

POINT

X

lJlJlJ1

-~

lJuuW

511SEC

POINT Y

nnnr

fLfL-fL

mrm

C23

VOLTAGE

OV------------------------

C25

VOLTAGE

OV------------------------

Figure

4-3.

Frequency-Meter

Bridge,

Simplified

Schematic

Diagram

and

Waveforms