Hal Communications ST-7000 Manuale utente

ST-7000

HF

Demodulator for Packet Radio

Copyright

by

HAL

Communications

Corp.,

Urbana,

Illinois.

Printed

in

the

United

States

of

America.

All

rights

reserved.

Contents

of

this

publication

may

not

be

reproduced

in

any

form

without

written

permission

of

the

copyright

owner.

870-07000

August, 1988

Printing

ST-7000

HF

DEMODULATOR

FOR

PACKET

RADIO

CONTENTS:

CHAPTER

1.

UNPACKING

AND

INSPECTION................................... 1

CHAPTER

2.

INSTALLATION

...............................................

2

2.1

DC Power............................................. 4

2.2

HF

Radio

Connection

..................................

4

2.2.1

HF

Receive

Audio

..............................

6

2.2.2

HF

Transmit

Audio

.............................

6

2.2.3

HF

PTT

Connection

.............................

7

2.2.4

HF

GROUND

Connection.......................... 7

2.3

Packet

Controller

Connections

........................

8

2.3.1

TNC

AUDIO

Interface

...........................

8

2.3.2

TNC

TTL

I/0

Connections

.......................

9

2.3.3 RPC-2000 RS232

I/0

Connections

................

12

2.4

VHF

RADIO

Connection.................................

14

CHAPTER

3.

OPERATION

..................................................

15

3.1

Controls

and

Indicators

..............................

15

3.1.1

HF/VHF

Switch.................................

15

3.1.2

SHIFT

Switch..................................

15

3.1.3

THRESHOLD

Control.............................

16

3.1.4

Tuning

Indicator

..............................

16

3.2 Use

of

the

ST-7000

...................................

18

3.2.1

General

Considerations

........................

18

3.2.2

HF

Packet

Operation

...........................

18

3.2.3

HF

R

TTY

and

AMTOR

Operation

...................

19

3.2.3.1

HF

PTT

Control.......................

19

3.2.3.2

HF

RX

Data

Squelch

...................

20

3.2.3.3

HF

Transmit

Tone

ON/OFF

..............

20

CHAPTER

4.

THEORY

OF

OPERATION........................................ 22

4.1

AF

Input

Filters

......................................

23

4.2 Receive

Audio

AGC

.....................................

23

4.3

Mark

Filter

-600

Hz

Shift

............................

23

4.4 Space

Filter

-600 Hz

Shift

...........................

24

4.5 200 Hz

Detector

and

SHIFT

Switch

......................

24

4.6

HF

Transmit

Tone Generator............................

25

4.7 RS232

and

TTL

I/0

Interface

...........................

26

4.8

TNC

Audio

Modem....................................... 26

4.9

TNC

Audio

Interface

and

PTT

...........................

27

4.10 Power Supplies

........................................

27

4.11

Tuning

Indicator

......................................

28

4.12

Threshold

Circuit

.....................................

28

4.13 ST-7000

Circuit

Board Arrangement.....................

28

CHAPTER

5.

TEST

AND

ALIGNMENT

.........................................

43

CHAPTER

6.

SPECIFICATIONS

.............................................

49

LIMITED WARRANTY

...........................................

50

ILLUSTRATIONS:

FIGURE

2.I ST-7000

REAR

PANEL.................................... 2

FIGURE

2.2 ST-7000

INTERNAL

JUMPER

LOCATIONS..................... 3

FIGURE

2.3

HF

RADIO

CONNECTIONS

.................................. 5

FIGURE

2.4

AUDIO

TNC

INTERFACE

CONNECTIONS.......................

IO

FIGURE

2.5

TTL

TNC

INTERFACE

CONNECTIONS.........................

II

FIGURE

2.6 RS-232

TNC

INTERFACE

CONNECTIONS

...................... I3

FIGURE

3.I ST-7000

FRONT

PANEL................................... I5

FIGURE

3.2

TUNING

INDICATOR

EXAMPLES............................. I7

FIGURE

4.I ST-7000

BLOCK

DIAGRAM.................................

2I

FIGURE

4.2

AUDIO

INPUT

FILTERS................................... 29

FIGURE

4.3

RECEIVE

AGC

CIRCUIT................................... 30

FIGURE

4.4 600

HZ

MARK

FILTER

....................................

3I

FIGURE

4.5 600

HZ

SPACE

FILTER

................................... 32

FIGURE

4.6 200

HZ

DETECTOR

.......................................

33

FIGURE

4.7

HF

AFSK

GENERATOR..................................... 34

FIGURE

4.8 RS-232

AND

TTL

1/0

INTERFACE

..........................

35

FIGURE

4.9

TNC

AUDIO

MODEM....................................... 36

FIGURE

4.IOTNC

AUDIO

I/0

AND

HF

PTT

..............................

37

FIGURE

4.II

ST-7000 POWER SUPPLIES ................................ 38

FIGURE

4.I2TUNING

INDICATOR...................................... 39

FIGURE

4.I3THRESHOLD

AND

CARRIER

DETECT.......................... 40

FIGURE

4.I4ST-7000

MAIN

CIRCUIT

BOARD............................

4I

FIGURE

4.I5ST-7000

DISPLAY

CIRCUIT

BOARD......................... 42

HAL

COMMUNICATIONS CORP.

ST-7000

HF Demodulator for Packet Radio

Operator's Manual

CHAPTER

1

UNPACKING

AND

INSPECTION

When

unpacking

the

ST-7000,

carefully

inspect

the

shipping

carton

and

the

cabinet

for

shipping

damage.

Any

evidence

of

shipping

damage

should

be

immediately

reported

to

your

shipping

carrier.

Be

sure

to save all

packing

materials

if

damage

is

found

-

the

shipping

carrier

will

want

to

inspect

them.

Before

discarding

the

packing

materials

check

that

you

have

all

parts

and

accessories

listed

below.

If

any

are

found

missing,

notify

HAL

Communications

Corp.

immediately.

Be

sure

to

fill-out

and

mail

the

enclosed

Warranty

Card

to

HAL

Communications.

1 900-07000 ST-7000

HF

Demodulator

The

following

accessories

are

included

with

the

ST-7000:

1 770-05000

1 800-01002

1 960-07232

3 355-00054

1 870-07000

Spare 0.5A

fuse

115VAC to 12VDC Power Supply

5-pin

TTL

I/0

Cable

5-pin

DIN

to Phono Cable

ST-7000

Preliminary

Operator's

Manual

The

following

accessories

are

available

at

extra

cost:

855-00006 RS232C Cable

333-20250 DB25

Connector

333-51228 DB25

Connector

Shell

310-00064 5-pin DIN

Connector

327-05000 5-pin

TTL

Connector

You

may

also be

interested

in

the

following

products:

RPC-2000

Radio

Packet

Controller

Board

(for

PC-XT

& DS-3200)

DS-3200

Radio

Data

Terminal

(100% PC-XT Compatible)

HAL880815

ST-7000

OPERATOR'S

MANUAL

PAGE

2

CHAPTER

2

INSTALLATION

The

ST-7000 is a

modem

(MOdulator/DEModulator)

device

that

connects

between

your

packet

controller

(also

called

"TNC")

and

an

HF

receiver-transmitter.

The

packet

controller

is

NOT

included

in

the

ST-7000.

Proper

installation

of

the

ST-7000

requires

(a) DC

power

connection,

(b)

HF

radio

connection,

and

(c)

packet

controller

connection.

The

rear

panel

of

the

ST-7000 is

shown

below

in

Figure

2.1. All

connections

to

the

ST-7000

are

made

to one

or

more

of

these connectors.

FIGURE

2.1

ST-7000

REAR

PANEL

Many

of

the

1/0

connections

available

on

the

ST-7000 will

require

changing

of

internal

jumpers.

Therefore,

when

making

the

first

installation,

REMOVE

the

ST-7000

top

cover

before

starting.

There

are

NO

hazardous

voltages

inside

the

ST-7000,

but

use

care

to

avoid

damaging

components

or

accidently

shorting

out

circuits

with

stray

wires

while

power

is

applied

to

the

ST-7000.

To

remove

the

top

cover:

1.

Remove

all

cables

connected

to

the

ST-7000

rear

panel.

2.

Remove

the

two

screws

at

each

side

of

the

cabinet

(4 screws total).

3.

Lift

from

the

front

and

swivel

the

top so

that

it

lies

upside

down

behind

the

ST-7000.

4.

Unplug

the

ground

jumper

wire

and

set

the

top

cover

aside.

5.

Preliminary

tests will be

made

with

the

cover

OFF.

The

cabinet

cover

may

be re-assembled

after

all

jumpers

and

connections

are

set.

Location

of

the

internal

jumpers

is

shown

in

Figure

2.2.

HAL880815

ST-7000

OPERATOR'S

MANUAL

PAGE

3

Jl J2 J3 J4

R6

J5 J6

TNC

RPC-2000

HE

VHF

.1:1£

:roc

PO\JER

TTL

I/0

RS-Z32

l/0

RAlllil

Will

.A£SK

AUDIO

mvDc

II I I I I I

101

I

~

I I I I FI I

TPl

0

TP2

0 0

TP4

0

TP3

TP5

0

GND

TTL

JlO

J7!

GND

WJI

~

II

-Jll

PTI

.lijl

-J9

-J8

RTS

• .

TIMER

TP12

0

~

AUDIO

DEFEAI

TP6

0

~R37

~1200

[!]~2

0

TP13

TP7

0

~R41

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TPlO

0

~R77

~2210

.Q.__gBr!

llliEl

J12

R51

~

~R57

.oo~

~w

RS

2 o

TP8

~~

~R54

CD

J13

~

-'llQ

J14

il

~

TP9

+SV

"--AFSK

ON/OFF

m.

SQUELCH

0

TP16

o

TP17

y

~

I

[!]

GNDo

TP14

0

[!]

0

TP15

RHO

R117

G~JD

o

TP18

0 0

R91

R92

FS

2510

@]

R101

Mb.

FM

121Q.

oormoon

J14

FRONT

PANEL

S\Jl

S\J2

.s!:!IEI.

fD.'iER

FIGURE

2.2 ST-7000

INTERNAL

JUMPER

LOCATIONS

HAL880815

F1

.SASB

ST-7000

OPERATOR'S

MANUAL

PAGE

4

2.1

DC Power:

The

ST-7000

requires

a

minimum

of

13

VDC @ 225 rna power.

This

is

supplied

by

the

enclosed accessory DC Power

Supply

or

from

other

sources

of

DC power.

The

connector

on

the

HAL

DC Power Supply is

already

set-up

for

the

ST-7000.

If

using

your

own DC power source, be

sure

to observe

correct

polarity.

The

ST-

7000

DC

connector

uses

the

center

as

the

oositive

terminal.

BE CAREFUL!

Other

devices

with

similar

appearing

DC connectors

may

use a

different

polarity

as well as a

different

diameter

center

pin.

If

you

accidently

reverse

the

power

supply

polarity,

it

should

not

damage

the

ST-7000

circuits,

but

it

will

blow

the

fuse

inside

the

ST-7000!

Any

DC

power

supply

used

with

the

ST-7000

should supply

13.5 to

15

VDC

at

0.250

A.

2.2

HF

Radio

Connection:

The

HF

Radio

equipment

is

connected

to

the

"HF RADIO" 5-pin

DIN

connector

on

the

rear

panel.

If

you

are

preparing

your

own cables,

pay

close

attention

to

the

numbers

marked

on

the

rear

panel.

The

"industry

standard"

numbering

on

these

connectors

does

NOT

go

in

a

logical

progression!

Connections

are

as follows:

USE

1

Transmit

tones to

HF

transmitter

audio

input

2

GROUND

3

Push-to-Talk

(PTT) to

transmit/receive

control

4

Audio

output

of

HF

receiver

5

Not

used

Shell

GROUND

(Cable shields)

An

accessory

cable

(P

/N

355-00054) is

supplied

that

conveniently

converts

the

5-pin

DIN

connections

to

individual

"RCA-style"

phono

plugs. Some

HF

radio

equipment

(notably

Ten-Tee)

have

rear

panel

phono

connectors to

which

this

adapter

cable

may

be

directly

connected.

Other

radio

connectors

may

require

that

you

either

make

your

own complete cable set

OR

adapt

the

phono

connector

to one

that

matches

the

connector

on

your

radio.

For

HF

radio

connections,

the

following

color code applies to

the

HAL

adapter

cable.

CABLE

COLOR

RED

BLACK

WHITE

YELLOW

HF

RADIO

CONNECTIONS

DIN

to

PHONO

Adapter

Cable

USE

TONES

TO

HF

TRANSMITTER

Push-To-

Talk

(PTT)

AUDIO

FROM

HF

RECEIVER

--

not

used --

ST-7000

HF

RADIO

NO.

1

3

4

5

NOTE:

Ground

(pin

2)

is

connected

to ALL phono

connectors

A

typical

ST-7000 to

HF

Transceiver

connection

is

shown

in

Figure

2.3. A

detailed

discussion

of

the

requirements

for

each

connection

is given

in

the

sections

following

Figure

2.3.

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VI

ST-7000

OPERATOR'S

MANUAL

PAGE

6

2.2.1

HF

Receive

.Audio:

The

ST-7000 is designed to

work

equally

well

from

either

an

8

ohm

or

600 ohm

audio

output

on

your

receiver.

The

simplest

connection

is

direct

to

the

receiver

speaker

output

terminals.

Set

the

receiver

volume

control

to

a

comfortable

speaker

level

and

the

ST-7000 AGC

circuit

will do

the

rest.

If

you

have

a

constant

level 600

ohm

audio

output,

by all means use it. Some

radios

have

a

phone

patch

output

on

the

rear

panel

-

if

so, use it.

The

ST-7000

may

also

work

with

some "recorder"

outputs

provided

on

some receivers. However,

the

output

impedance

and

voltage level

output

may

not

provide

sufficient

audio

signal

for

the

ST-7000

and

may cause

reduced

performance

during

signal

fades.

Be

sure

to use

shielded

cables between

the

ST-7000

and

the

receiver

audio

output

connector.

2.2.2

HF

Transmit

Audio:

The

ST-7000 is set

at

the

factory

for

a level

of

-20 dBm (80 mY) to

the

transmit

audio

output

connector.

This

level

may

be

reduced

to as low as a

few

millivolts (-50 dBm)

by

adjustment

of

the

"HF AFSK"

screw-driver

control

on

the

rear

panel. Conversely,

if

ypur

transmitter

system

requires

a

higher

level

output,

internal

jumper

Jl2

may

be

installed

to

increase

the

maximum

level

output

to 0 dBm (800 mY). With J12

in

place,

the

"HF AFSK"

control

will

adjust

over

the

-30 to 0 dBm

range

(25 to 800 mY).

The

microphone

input

of

most

SSB

transmitters

will

require

a level

of

between -40

and

-20 dBm (8 to 80 mY).

Be

sure

to use a

shielded

cable between

the

ST-7000

and

the

transmitter

audio

input.

Use

the

following

procedure

to set

the

"HF AFSK" level control.

1.

Turn

OFF

transmitter

VOX

and

SPEECH PROCESSOR

features.

2.

Set

the

transmitter

to LSB mode.

3.

Set

transmit

MIC

LEVEL

to

"0".

4.

Set ST-7000 to "200"

SHIFT

and

turn

ON ("HF" position).

5.

Set ST-7000

HF

AFSK to

maximum

(full

CW

as

viewed

from

rear).

6.

Be

sure

transmitter

is

connected

to a

load

(antenna

or

dummy

load).

7.

Turn

transmitter

to XMIT.

8.

Slowly

increase

MIC

LEVEL

until

50%

of

full

transmitter

power

output

is

noticed.

Note

the

position

of

the

MIC

LEVEL

knob.

9.

Turn

transmitter

OFF.

10.

If

50%

transmitter

power is

achieved

in

first

third

of

the

MIC

LEVEL

rotation,

change

the

setting

of

"HF AFSK" (CCW)

and

try

step

8 again.

Keep

adjusting

MIC

LEVEL

and

"HF AFSK"

until

50%

transmitter

power is

achieved

at

between

1/3

and

1/2

rotation

of

the

MIC

LEVEL

control.

HAL880815

ST-7000

OPERATOR'S

MANUAL

PAGE

7

11.

If

50%

transmitter

power is

achieved

at

greater

than

1/2

rotation

of

the

MIC

LEVEL

control,

install

jumper

Jl2

inside

the

ST-7000.

Be

sure

to

turn

OFF

the

ST-7000

before

removing

its

cover.

The

jumper

for

J12

is

installed

at

the

factory

with

just

one

covered.

Unplug

the

jumper

and

re-install

it

to

short

out

the

pins

at

Jl2.

After

installing

the

Jl2

jumper,

go

back

to step 8

and

adjust

MIC LEVEL.

12.

If

installing

Jl2

still does

not

give

adequate

MIC

LEVEL

settings,

turn

everything

OFF

and

inspect

your

cables -something is WRONG!

13.

Set

the

MIC

LEVEL

control

to

the

desired

transmitter

output

level. Since

most

transmitters

are

designed

for

SSB

voice (50%

duty

cycle), using less

than

full

power

for

data

is a

prudent

move

and

may

greatly

prolong

the

life

of

your

transmitter.

The

difference

between

1/2

power

and

full

power

is only

1/2

an

S-unit

on

the

other

station's

receiver,

hardly

worth

the

risk

to

your

transmitter!

2.2.3

HF

PTT

Connection:

The

ST-7000 Push-to-

Talk

(PTT)

output

is a

relay

contact

switched

to ground.

The

relay

can

adequately

switch

PTT

control

lines

that

have

up

to 50 VDC

at

a

maximum

current

of

0.25 amperes.

This

should

switch

virtually

ANY

transmitter

or

transceiver

available.

A

shielded

cable is recommended

but

not

required

for

the

PTT

connection.

Often,

a

two-conductor

shielded

cable

can

be used to

carry

both

transmit

audio

and

PTT

signals

from

the

ST-7000 to

the

transmitter

microphone

input

jack.

The

ST-7000

HF

PTT

output

includes

a 20 second

safety

timer

for

packet

radio.

This

timer

prevents

long key-down periods, even

if

your

TNC

or

computer

malfunctions.

This

safety

feature

helps

prevent

transmitter

burn-out

in

a

malfunctioning

packet

radio

system.

The

timer

resets

after

each

packet

is

sent

and

the

TNC

PTT

control

line

returns

to receive state.

However,

the

ST-7000 may also be used as

an

RTTY

or

AMTOR

FEC

modem. In

this

case, long key-down

transmitter

periods

are

common

and

internal

jumper

J7

may

be

installed

to

defeat

the

PTT

safety

timer.

To

defeat

the

timer,

move

the

jumper

plug so

that

it

shorts

the

two pins

·at

17.

The

jumper

plug is

positioned

at

the

factory

to cover one

but

not

both

pins

of

J7

(PTT

safety

timer

ON).

2.2.4

HF

GROUND

Connection:

The

ST-7000 MUST be

adequately

grounded

to

the

HF

transmitter

and

receiver.

Grounding

is

done

in

TWO

steps -

(I)

an

audio

ground

obtained

through

the

shielded

cables

between

the

HF

RADIO

connector

and

the

transmitter/receiver

audio

connections,

and

(2)

an

RF

ground

between cabinets.

The

importance

of

a

good

RF

.ground

cannot

be over-emphasized! Use a

short

length

of

1/4"

shield

braid

directly

between

the

transmitter

/receiver

cabinet

and

the

ST-7000

rear

panel

ground

screw. An

earth

ground

for

the

entire

radio

station

is a good

safety

feature

but

does

NOT

replace

the

need

for

a

seoarate

RF

ground

connection.

HAL880815

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