Though the IC-730 is a good-performing, reliable radio, many of these units have
been in service for a number years and are beginning to show their age. The
following preventative maintenance procedures should be done to all IC-730's that
come in for repair. You will find that when you take a few minutes to attend these
minor details while the radio is on your bench, your return-repair rate for the
IC-730 will be almost nil.
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On the RF unit, resolder the connectors at J2 and J3 on the RF unit. Due to
the relatively thick coax cables on the connectors, these joints tend to crack
with age and cause intermittent transmit and receive problems.
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Make sure the receiver preamp works. If inoperative, replace relay RL1 on the RF
unit. Install the factory update to prevent relay failure
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Check transistor Q5 on the RF unit. If it is a 2SC945Q, replace it with the
improved 2SC2878B to prevent spurious output from the transmitter and failure
of the driver transistors. If Q5 is a type 1636, it doesn't need to be
replaced.
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Clean the RIT pot and switch with tuner cleaner. These controls are usually
noisy and erratic, making the RIT hard to use.
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Tighten the chrome-plated PC board mounting screws. The type of screw and spacer
used in the IC-730 tends to come loose if the radio is used in a high-vibration,
mobile environment. Don't forget to tighten the screws on the logic and IF units
located beneath the main unit.
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Check the bandwidth coupler for proper tightness. Tighten as needed.
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