Tokyo Hy-Power HL-1.5KFX User Manual page 13

7-1
Connect AC cord and coax cables as illustrated above. Connect the cable from "SEND" to ACC or
the remote terminals of transceiver, where it is marked "SEND" or "TX GND". These terminal pins are
shorted to ground when the transceiver is in TX/ON AIR mode. If these connections are not made, the
amplifier will not go into TX (amplification) mode. For a temporary check to the amp, ground the SEND
center pin by inserting an RCA plug whose center pin has been soldered to the outer case of the plug
with a small piece of wire. As a side note, this SEND terminal is pulled up to a DC 5V level that is
connected to a internal microprocessor pin. When grounded, DC sink current of 1 mA (only) will flow. The
transceiver's control circuit is under a very light load.
7-2
At first, turn the ALC knob full clockwise to avoid ALC voltage to the transceiver. Application of ALC
will be covered in the following section 8.
7-3
Keeping the POWER (AC mains) switch off, check the SWR of your antenna by keying the
transceiver to TX mode (CW or RTTY mode). Monitor the SWR with an external SWR/Power
meter. If SWR is 1.8 or higher at band center, the antenna has to be adjusted for lower SWR.
As an alternative, an antenna tuner may be inserted.
7-4
Turn the POWER switch on. Turn the BAND switch to MANUAL position. Then push UP/ DOWN
keys to select desired band. Turn the STAND-BY switch to OPER (operate) position and the amplifier is
ready to go. If you key the transceiver with the carrier level set relatively low (such as 20-30W), you will
achieve an amplified output signal of a few hundreds watts. Monitor this output with the multimeter in the
(Pf position) or with an external power meter. Increase drive level to roughly 50W and see if the antenna
SWR stays constant. (As higher RF currents flow some antennas may show a changed SWR value due
to heated connector junctions and trap coils.)
7-5 Y
ou can now increase the drive level to nearly 80-90W to achieve maximum carrier output power of
900W (CW, RTTY) from the amplifier. If you change to SSB mode, peak voice power will reach
approximately 1kW. For high duty cycle transmissions like RTTY, SSTV, or FM modes, it is
recommended you reduce the drive power by 20-30% compared with SSB/CW. In AM mode, the drive
power should be strictly reduced to one third of SSB, or 30W at most, otherwise modulated amplitude
peaks will be distorted.
7-6
With a high power transceiver in SSB mode, you can overdrive the amplifier resulting in a distorted
output signal. This can also occur if you speak too loud or if you set the microphone gain too high. Speak
into the microphone properly to reduce the possibilities of splattering into the neighborhood. The ALC is
effective in preventing the output signal from being distorted or to limit the carrier level to within rated
output levels. As long as you do not overdrive, you can disregard the ALC connection. See Section 8,
ALC CONNECTION for details.
7-7
Protection circuits may work during operation depending on the conditions. If the protection circuit
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