RF Power HVLA1K3 PLUS User Manual page 9

PLUS
HVLA1K3 USERS MANUAL
6 CONNECTION AND OPERATION with KENWOOD™ transceiver
6.1 Connect AC power cord and coax cables as mentioned on page 9. Run a shielded cable from
the transceiver "REMOTE" connector to the amplifier rear panel "RELAY" phono (RCA) female
connector. The phono (RCA) female connector center pin is to be shorted to ground through the
relay circuit of the transceiver; the total keying current is under 10 mA. If these connections are
not made, the amplifier will not go into TX (amplification) mode. For a temporary check to the
amplifier, ground the "RELAY" center pin by inserting a RCA plug whose center pin has been
soldered to the outer case of the plug with a small piece of wire.
6.2 Connect a wire-to-wire DSUB (9pin) female – DSUB (9pin) female high quality shielded
cable, from RS-232 COM port of your transceiver to the amplifier rear panel "AUTO A" D-SUB
(9pin) male connector.
6.3 Set RS-232 COM port of your transceiver to 19200 bps and 1 stop bit.
6.4 Use a short 50 ohms coaxial cable, type RG58 or equivalent for the connection from the RF
output of the transceiver to the amplifier rear panel "RF IN" SO-239 connector.
6.5 Keeping the main power switch OFF, check the VSWR of your antenna by keeping the
transceiver to TX mode (CW, FM or RTTY mode). Monitor the VSWR with an external SWR/power
meter. If VSWR is high, the antenna has to be adjusted for lower VSWR. As an alternative, an
antenna tuner may be inserted.
6.6 Turn the main power switch ON. Turn the "BAND" rotary switch to "AUTO A" position (green
LED "AUTO A" will light). Turn the "ANTENNA" rotary switch to a specific antenna, if necessary.
Turn the "STBY-OUT" rotary switch to the low output power position of the amplifier (green LED
"LOW" will light). Now, key the transceiver with the carrier level set relatively low (such as 10
watts) and monitor the antenna VSWR and the output power with an external power meter.
NOTE: turn ON the transceiver, first !
6.7 Now increase the drive level to nearly 40 watts to achieve nominal output power of more
1000 watts from the amplifier. Monitor the output power and if the antenna VSWR stays constant
(as higher RF current flow, some antennas may show a changed VSWR due to heated components
such as trap coils).
6.8 With a high power transceiver in SSB mode, you can overdrive the amplifier in a distorted
output signal. This can occur if you speak too loud or if you set the microphone (or compressor)
gain too high. Speak into the microphone properly to reduce the possibilities of spattering into the
neighborhood. You can reduce the RF output power, also.
6.9 Protection circuits may work during operation depending on the conditions. For more details
on this protection circuits, see section 13. PROTECTION CIRCUITS.
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