The MST400 (Minimalist Sideband Transceiver) - Blog - PA7MU

Discover the thrill of making contacts with a rig you built yourself.

The MST (Minimalist Sideband Transceiver) is an easy to build and fun to use single sideband QRP transceiver for the 40M or 80M amateur bands. The MST transceiver follows a minimalist design making it inexpensive and simple to build yet still delivering excellent performance and being a pleasure to operate.
The MST PCB contains a complete transceiver except for a VFO. You can add a VFO of your own, as long as it has the correct frequency range and drive level, but to obtain best results it should be used with the companion DDS VFO. The DDS VFO offers drift free performance and features a clear backlit LCD display, selectable frequency steps and programmable IF offset.

MST Features:
1.Complete SSB transceiver on a single PCB (just add a VFO).
2. Superhet receiver using a 4 pole 10MHz crystal filter.
3. 5W PEP minimum power output using a rugged power MOSFET output stage.
4. Unwanted sideband suppression is typically 40dB.
5. All spurious transmit outputs below -45dBc.
6. AF and microphone gain controls.
7. Easy to adjust and set up.
8. Front panel LED transmit power and modulation indicator.
9. Plenty of audio output to drive a loudspeaker.
10. High quality double sided PCB with groundplane, solder mask and silk screen.
11. Simple and easy to build using all through hole components.
12. No complicated coil winding required. Uses inexpensive commercial coil assemblies for tuned circuits.

DDS VFO Features:
1. Stable frequency – no more drift!
2. Simple to operate using a single rotary encoder control with press button switch.
3. Bright 16 character by 2 line LCD display. Can be used with non-backlight display to reduce current consumption.
4. Output frequency range of 1MHz to 10MHz.
5. Selectable 1KHz, 100Hz or 10Hz frequency steps.
6. Tuning lock control.
7. Displays power supply voltage.
8. Programmable IF frequency. Ensures the displayed frequency is the same as the transmitted frequency.
9. Programmable IF offsets: Minus, Plus, None.
10. Draws only 80mA at 13.8V DC (with LCD backlight).
11. Spurious outputs at least -45dB.
12. Typically 300mV pk-pk sine wave output.
13. High quality double sided PCB with ground plane, plated through holes, solder mask and silk screen.
14. Simple and easy to build using through hole components apart from one SMD chip. To assist constructors the PCB comes shipped with the SMD chip already installed.
Large single sheet MST circuit diagram and much more info see: http://www.ozqrp.com/index.html