Hammarlund HX-50 - Page 32

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m

on

oscilloscope

by

advancing

"Audio

Level"

control

CW.

Repeat

for

"USB"

position.

Rotate

"Audio

Level"

control

maximum

CCW

and ob-

serve

level

indi

cator

ML

Reading

in

either

"USB"

or

"LSB"

position

of

the

"Function"

switch

should

be

less

than

-50

db with

the

"Operations"

switch

on

"MOX".

5.

With

"Operations"

switch

on

"MOX"

and

"Function"

switch

on

"DSB",

tune

up

trans-

mitter

first

at

3.5

mcs

and

then

at

4

mcs

in

the

80M

band.

At

each

frequency

rotate

"RF

Level"

control

until

power

meter

reads

100

watts

or

over.

Observe

the

current

meter

and

note

that

the

read-

ing

does

not

exceed

260 rna.

Rotate

"Band

Selector"

to 40M.

Record

power

output

and cur-

rent

readings

as

above

at

7 and

7.5

mcs.

Rotate

"Band

Selector"

to 20M, 15M,

and

the

four

10M

bands,

each

time

checking

for

power

and

current

readings

at

the

scale

extremes

as

above.

NOTE:

On

the

10M

bands

an

output

power

reading

of

70w. or

better

is

acceptable.

6.

Connect

the

key

(bug to

"Key"

jack

on

the

front

panel.

Rotate

"Function"

switch

to

"CW".

Operate

key

and note

that

power

output

with

the

key

down

is

over

100

watts.

Send a

series

of

dots

and

note

the

rise

and

decay

time

of

the

RF

power

on

the

oscilloscope.

This

should

be

simi-

Iar

to

that

observed

on a

tested

and

approved

HX-500.

7.

Connect

a

microphone

to

the

"Mike"

input

on

the

front

panel.

Rotate

"Function"

switch

to

"LSB".

Advance

the

"Audio

Level"

control

to

about

"5"

and

talk

into

the

microphone.

Observe

the

RF

signal

on

the

oscilloscope.

8.

Rotate

"Function"

switch

"FSK"

and

"Opera-

tions"

switch

to

"CAL".

Tune

receiver

to

3.75

mcs

and

set

receiver

BFO

to

zero

beat

with

3.75

mcs

signal

from HX-500.

Connect

the

key

(bug)

to

pins

11

11

and

11

12

of

]Il.

While

sending

a

series

of

dots,

rotate

the

"FSK

DEVIATION"

control,

Rl40,

until

a low

beat

note

is

heard

in

the

re-

ceiver

each

time

the

key

makes

contact.

This

sets

the

"FSK

DEVIATION"

control

at

the

minimum

deviation

(zero)

position.

Send

a

series

of

dots

and

rotate

the

"FSK

DEVIATION"

con-

trol

first

CW

and

then

CCW

from

the

point

of

"Zero"

beat.

As

the

control

is

advanced

in

either

direction,

a

series

of

dots

sent

with

the

key

should

increase

in

audio

pitch

to

at

least

1500

cycles.

As

shipped

from

the

factory

after

tests

the

"FSK

DF:VIATION"

control

R140,

should

be

set

at

the

extreme

CW

position.

9.

With two

tone

audio

generator

and

oscilloscope

connected

as

in

Step

5,

tune

up

transmitter

on

"DSB"

position

in

the

80M

band

at

3.75

MCS.

Set

meter

indication

to ODB with

the

"Meter

Sensitivity"

control

and

then

adjust

"RF

Level"

control

until

meter

reads

-10

db.

Switch

to

"LSB"

position

and

advance"

Audio

Level"

control

to

exact

position

obtained

in

Step

4

where

pattern

on

oscilloscope

shows

no

signs

of

flutter.

Ad-

vance

"RF

Level"

control

until

there

is

a

defi-

nite

flat-topping

of

pattern

on

oscilloscope.

Ad-

just

"ALC

AD]"

control,

R124,

until

the

pattern

returns

to

original

shape

at top of

wave

form.

This

completes

the

test

and

alignment

of

the

transmitter.

Page

31

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