Maintenance
5-2 HF SSB Transceiver 9323/9360/9390/9780 Technical Service Manual
Circuit boards
Excessive heat
Excessive heat may lift the track from the circuit boards. This will cause serious
damage. Avoid the use of high-powered soldering irons. A soldering iron rated at
a maximum of 60 W, preferably temperature controlled at approximately 370°C,
is sufficient for most tasks. A soldering iron, rated at a slightly higher temperature
of 425°C, may be required for heavier components such as PA transistors. Only
apply the soldering iron long enough to unsolder an existing joint or to solder a
new one.
Unsoldering
When unsoldering, use a solder-sucker or Solder wick to remove solder.
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Do not use sharp metal tools such as screwdrivers or twist drills as these may
damage the printed circuit track and plated through-holes.
Component substitution
Avoid unnecessary component substitution as this may damage the component,
the circuit track or adjacent components.
Component replacement
When a component is diagnosed as defective, or the fault cannot be diagnosed in
any other way than by substitution, observe the following when replacing
components:
• Axial leads—Components with axial leads, such as resistors and capacitors,
can often be replaced without unsoldering the joints on the boards. The
defective component can be removed by clipping its leads close to the
component, leaving the leads soldered to the board. These leads should be
straightened, so that the leads of the replacement component can be wrapped
around and soldered to them. After soldering, the excess lead should be clipped
off.
• Remove solder—When a component has been unsoldered from the board,
ensure the holes are clear of solder before inserting the leads of the
replacement.
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Never force the leads through the holes as this will damage the circuit track,
particularly where plated through–holes are used.
• Observe orientation—Before replacing defective diodes, transistors, electrolytic
capacitors or integrated circuits, observe any markings that indicate polarity or
orientation. It is essential that these types of components are installed correctly.
If necessary, consult the manufacturer's data for indications of the polarity of
diodes, capacitors and transistors.
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