Kenwood TS-850S - Manual (Page 8)

(1) Antenna (4) Key connection
Caution
Protect your equipment — Use a LIGHTNING
ARRESTER.
The type of antenna that is used will greatly affect
the performance of the transceiver. Use a properly
adjusted antenna, of good quality, to enable your
transceiver to perform at its best. The antenna input
impedance is 50 ohms. Use 50-ohm coaxial cable
such as 5D-2V or RG-213/U (RG-8A/U) for this
connection. If the antenna is far from the transceiver
the use of low loss coaxial cable, such as 5D-2V or
RG-213/U (RG-8A/U) are recommended. Match the
impedance of the coaxial cable and that of the
antenna so that the SWR is less than 1.5 to 1. The
protection circuit in the transceiver will activate if the
SWR is particularly poor (greater than 3 to 1). High
SWR value will cause transmitter output to drop, and
may lead to TVI or BCI reports.
(2) Grounding
Caution
Never use a gas pipe or electrical conduit pipe.
Notes
1. A ground connection that is a 1/4 wavelength or
its multiple may provide a good DC ground, but
it will not provide a good RF ground.
2. A city water pipe cannot be used as a good
earth in some cases.
Your key should be connected as illustrated in the
figure below. When using an electronic keyer, make
sure that polarity is set for positive. Always use
shielded line from the key to transceiver, (diameter
6.0 mm)
|To use external straight key
Ground Not used +
or
+5V, Contact
Current about 1
mA
-I-5V, Contact
Current about 1
mA
Ground +
Note
Check the polarity of the plug when you use an
electronic keyer.
Please refer to Section 4-4.
Making a good earth connection is important for
preventing dangers such as electric shock and for
emitting a high quality signal with minimum spurious
radiation. Bury a commercially available ground rod
or copper plate under the ground and connect it to
the GND terminal. A thick wire, cut as short as
possible, should be used for the connection. To
make a good earth connection, connect the GND
terminal to a grounded metal water pipe.
(3) External speaker
The TS-850S includes a built-in speaker. If you
would like to use an external speaker, such as the
SP-31, it may be connected to the EXT SP jack on
the rear of the transceiver. The speaker may be any
good 8 ohm permanent magnet type speaker. The
diameter should be at least 4 inches for good audio
quality. If you plan on using a speaker other than the
SP-31 it should be equipped with a miniature phone
jack plug, (diameter 3.5 mm)
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