ozQRP MST3 Construction And Operation Manual page 30

Step 4: Non-polarized capacitors
Note the various types. Ceramic disc (standard and NPO), polyester MKT and ceramic multi-
layer chip capacitors (MLCC). These are all non-polarized and can go in either way.
There are 29 x 100nf (0.1uF) MLCC and as they are quite small install these first. Follow this
with the disc ceramics and finally the MKT.
Ceramic disc Polyester MKT Ceramic MLCC
Step 5: Trimmer capacitors
The trimmer capacitors have
one lead electrically
connected to the
screwdriver adjustment slot.
Use a multimeter to
determine this pin and
solder to the hole in the PCB
connected to the ground
plane. TC1 ground pin goes
towards Q1.
Earth pins
The 40pF sideband
trimmers are yellow and the
30pF carrier balance
trimmer is green.
Step 6: Trimpots
Note that the carrier balance trimpot is a multi-turn vertical mount while the PA bias, AGC and
sidetone trimpots are horizontal mount types.
MST3 Construction and Operation Manual – Issue 1 Page 30