Mounting The Pcb; Figure 17 Mst3 Board And Rear Panel - ozQRP MST3 Construction And Operation Manual

11.3 M
OUNTING THE
This section assumes the PCB is mounted in a plastic enclosure, but the same general procedure
applies for other enclosures.
Temporarily put the rear panel in place and sit the PCB on the mounting pillars. If needed bend
the leads of Q14 slightly so that the metal tab is resting parallel against the rear panel. Use a
sharp pencil or scriber and run around the inside of the hole in the tab to mark the position for
the mounting hole on the rear panel. Remove the rear panel and drill a 3mm hole ensuring that
you remove all burrs.
Screw the PCB to the mounting pillars using small self-tapping screws. Slide an insulating
washer between the rear panel and Q14 tab. Insert a plastic bush into Q14 tab then pass a 3mm
screw from the rear through the bush and screw on a nut and tighten.
Figure 17 shows how the MST3 board is mounted inside an enclosure and the wiring to the rear
connectors. It also shows the output PA MOSFET screwed to the rear panel to act as a heatsink.
Check with a multimeter that there is no electrical connection between the rear
panel and Q14 tab.
MST3 Construction and Operation Manual – Issue 1
PCB

Figure 17 MST3 board and rear panel

Page 47