Henry Radio 3K Classic Mark II Operating And Maintenance Manual page 7

of your plug type.
CAUTION: The amplifier will be damaged if the green
wire is connected to the 220 VAC terminal. Make sure
that the green is connected to the neutral terminal.
ANTENNA COAX - Use only RG-8/U coax (or better) to connect the amplifier
to the antenna or dummy load. A PL-259 (UHF type) coax connector is in-
cluded in the accessory kit. Prepare the cable and connector as described
in Figure 1 below.
The PL-259 mates with the coax jack marked OUTPUT on
the rear panel of the amplifier. The 5K. Classic uses an N type connector
which is supplied in the accessory kit.
CAUTION:
Never operate the amplifier unless it -_on-
nected to an antenna or a dummy load capable of hand-
the output of the unit. You will damage the equip-
ment if you operate it without a load or into a load
with
an SWR greater than 2:1 (a reflected power more
than 10% of the forward power). Measure the antenna's
SWR with an SWR meter, using only the exciter output,
before operating the amplifier.
With the amplifier in
the off position, the exciter output will pass through
the amplifier directly to the antenna.
DRIVE CABLE
- The R8-58/U drive cable supplied in the accessory kit con-
nects to the INPUT connector on the rear panel of the amplifier. This con-
nector is a BNC type coax connector. The UHF connector on the other end of
the cable must be connected to the f2F output connector of the exciter.
An
adapter may be required if the exciter does not have a matching connector.
ALC (Automatic Level Control) CABLE - Plug the gray ALC cable into the ALC
OUT
phono socket on the rear panel of the amplifier and into the ALC feed-
back connection on the exciter. If the exciter does not have provision for
feedback of ALC voltage from the amplifier, no connection is necessary.
RELAY
CABLE - The gray relay control table must be plugged into the phano
plug marked RELAY on the bark panel of the amplifier.
This cable conducts
the keying signal from the exciter to switch the amplifier to the transmit
condition
and must be connected to the socket or connector marked antenna
relay (or its equivalent) on the exciter. The exciter needs to supply only
a shorting relay contact (closed to ground during transmit) to key the amp.
CAUTION:
Never
apply any voltage to the relay jack of
the amplifier!
Your amplifier has a built-in power
supply which provides the necessary voltage.
Most
modern transmitters or transceivers make easy provision for a relay
control connection.
If the connection is not obvious to you, examine the
operating
manual of'the exciter to find an available unused relay contact
that is normally closed during transmit.
Some
modern transceivers use diode switching rather than relay switching.
Henry amplifiers use 12 VDC (or 26 VDC) relay control voltage, any resis-
tance across the relay control line may keep the amplifier from keying. If
your
exciter will not key the amplifier, you should check the resistance
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