Alc Connection - Tokyo Hy-Power HL-2.5KFX Instruction Manual

8-2-5 You can now increase the drive level to nearly 80-90W to achieve
maximum carrier output power of 1.4 kW (CW, RTTY) from the amplifier. If you
change to SSB mode, peak voice power will reach approximately 1.5 kW. 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.
8-2-6 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 page 15, Section 9. ALC Connection for
details.
8-7-7 Protection circuits may work during operation depending on the
conditions. If the protection circuit has shut down the amplifier, check the
antenna SWR, Vd, AC line voltage, or try to reduce the drive level. To reset, turn
off the ‡ A OPER/STBY switch once, then back on again. Note that some
protection modes need to reset the ‡ @ POWER switch(See page19, Section 11.
Protection & Safety Circuits for more details). The power transformer has an
overheat protection(130• Ž ) in the coil layer. If this temperature switch activates,
the amplifier will put you in receive mode with the cooling fan operating until the
transformer has cooled off. It may take ten to fifteen minutes to cool, depending
upon room temperature. In the same way, there is a built-in thermal switch
(100• Ž ) in the heat sink block of power FET's.

9. ALC Connection

ALC voltage is available at the terminal marked ALC (RCA phono jack) on the
right upper corner of the rear panel. Negative maximum DC voltage of ten volts
(-10 V) is produced at this terminal when the amplifier is fully driven. This voltage
is adjustable with the ALC ADJ. knob located above the ALC jack. If the ALC
voltage is properly fed back to the transceiver, you can keep the maximum
output power constant or hold the power at a certain level. Also ALC is useful in
avoiding your SSB signal from being distorted when overdriven. You may not
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