Icom IC-730 Instruction Manual page 6

For AC operation it is recommended that the optional
BC-10A be used.
3 – 5 ANTENNA
Antennas play a very important role in radio communi-
cation. If the antenna is inferior, your transceiver cannot
give you the best performance. With a good antenna and
feeder cable having 50-ohm impedance, you should easily
get the desired matching and performance. Carefully install
a high performance antenna that suits the frequency band(s)
you wish to operate on and place it as high as possible. Be
especially careful of the condition of the connectors as
loose connections will deteriorate the performance. Be sure
to connect the ground terminal of a whip antenna, if used,
to the body of your car.
As the output is quite high, avoid connecting the antenna
connector to open lines and do not transmit under mis-
matched conditions. Otherwise the final stage could be
overloaded and cause a malfunction of the unit.
3 – 6 GROUND
In order to prevent electrical shocks, TVI, BCI and other
problems, be sure to connect a heavy wire ground, as short
as possible, from a good earth point to the ground terminal
on the rear panel.
3 – 7 MICROPHONE
The microphone supplied with the IC-730 is the IC-HM7
which contains a preamplifier. The optional electret con-
denser type stand microphone IC-SM5 can be used. Their
circuit diagrams are shown.
Should you wish to use a different microphone, make
certain it has a proper preamplifier.
Microphone plug exploded view
Schema�c diagram of IC-HM7
Schema�c diagram of IC-SM5
3 – 8 CW KEY
When operating ON, connect the Key to the Key Jack
with a 1/4 inch plug. The connection of the pl ug is
shown below.
Key Wiring Diagram
If the terminals have polarity, be sure to make the correct
connection. Note that the keyed voltage when switching
with semiconductors or relays with resistors in the circuit,
should be adjusted to be below 0.4 Volts!
3 – 9 EXTERNAL SPEAKER
The IC-730 contains an internal speaker, and is also
designed so that it can drive an external speaker from
the external (EXT) speaker jack on the rear panel. Be
sure the impedance of the external speaker is 8 ohms,
and remember that with the external speaker connected,
the internal speaker is disabled.
-- 4 --