ozQRP MST400, Construction Manual

MST Construction Manual – Issue 1 

Page 2 

C

ONTENTS

1

Introduction .............................................................................................................................................................. 4

2

Block Diagram .......................................................................................................................................................... 5

3

Circuit Description ................................................................................................................................................. 6

3.1

SSB generator.................................................................................................................................................. 6

3.2

Transmit mixer ............................................................................................................................................... 6

3.3

Power amplifier ............................................................................................................................................. 7

3.4

Receive mixer .................................................................................................................................................. 7

3.5

Receive audio .................................................................................................................................................. 8

4

Parts List .................................................................................................................................................................. 14

4.1

Main Board Parts ........................................................................................................................................ 14

4.2

Band Specific Parts .................................................................................................................................... 16

4.3

Off Board Parts ............................................................................................................................................ 16

5

Construction ........................................................................................................................................................... 17

5.1

General ............................................................................................................................................................ 17

5.2

Construction Steps ..................................................................................................................................... 17

6

Enclosure ................................................................................................................................................................. 23

6.1

Rear Panel ..................................................................................................................................................... 23

6.2

Front Panel .................................................................................................................................................... 23

6.3

Mounting the PCB....................................................................................................................................... 23

6.4

Front panel label ......................................................................................................................................... 24

6.5

Fitting the DDS VFO ................................................................................................................................... 26

7

Wiring up ................................................................................................................................................................. 27

8

Testing and alignment ....................................................................................................................................... 29

8.1

General ............................................................................................................................................................ 29

8.2

Power on ........................................................................................................................................................ 29

8.3

Receive ............................................................................................................................................................ 30

8.4

Transmit ......................................................................................................................................................... 30

8.5

Carrier frequency adjustment ............................................................................................................... 32

9

Operation................................................................................................................................................................. 33