Table of Contents
Advertisement
12 W
IRING UP
12.1
GENERAL
The wiring diagram is shown in Figure 18. Use light duty hookup wire of different colours for
easy identification and twist parallel wires together. The connections that carry audio signals
should be in light duty shielded audio cable.
12.2 H
EADERS
Most PCB connections utilize 2.54mm (0.1") pitch polarized headers and mating plugs. These
are inexpensive, give a professional looking appearance and allow easy disconnection and
removal of the PCB if required. The plugs are comprised of a plastic housing and crimp contacts
which slide into the housing and click in place. If you don't have a suitable crimper it is best to
squeeze the contact wings around the wire with long nose pliers to hold in place and then
solder. Be careful not to use too much heat and solder as it will make it difficult to insert the
contact into the housing.
12.3 P
OWER SUPPLY
The power supply connection uses a screw terminal block because of the higher currents
involved.
12.4 A
NTENNA
The antenna connection uses short wires soldered between the antenna socket and PCB pins to
give a low resistance connection. You will also need to install a solder tag for the earth wire
under the closest antenna socket screw. Twist the two wires together and keep as short as
possible.
12.5 K
EY SOCKET
The key socket is wired in parallel with the PTT wires on the mic socket. Ensure that the ground
wires of each connector are common.
12.6
SWITCHES
The Tone switch is not polarized and can be wired in either way. The U/L toggle switch will
need wiring to suit the sideband selection front panel labelling.
12.7 VFO
If preferred the VFO RF cable can be made from shielded audio cable rather than coax cable as
the length is quite short.
The control cable can be a multi-wire cable or a set of twisted individual wires. The number of
wires used will depend on the capabilities of the selected VFO.
MST3 Construction and Operation Manual – Issue 1
Page 48
Advertisement
Table of Contents
