Alc Connection - Tokyo Hy-Power HL-1.5KFX User Manual

8. 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 (- 10V) 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, we advised you to 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 always need to connect ALC to the transceiver, if you set
the mic gain properly and do not overdrive the amplifier. Depending upon the manufacturer of the
transceiver, the suitable ALC voltage differs. ICOM may need 0~ -4V, and Yaesu may need 0~ -5V range.
Kenwood may need -6 ~ -8V maximum. Check your transceiver manual.
8-1
Prepare an ALC control cable using the RCA plug supplied in the package. Solder a single wire or
(more preferably) a shielded single wire to the center pin of RCA plug and solder the shield braid to the
outer side of the plug. Connect the control cable to the "ALC (or EXTERNAL ALC)" jack of the
transceiver. External ALC input is sometimes available at one of the pins of the "ACC" socket of the
transceiver as well.
8-2
At first, turn ALC ADJ. full clockwise. Drive the amplifier in CW/RTTY mode
to full output power. Then turn the ALC ADJ counter-clockwise. Observe the SWR/Power meter
at the output, (or Pf of the multimeter). Stop turning the ALC ADJ at the point the power starts to
decrease. Or if you wish to further reduce the power, keep turning ALC ADJ until the desired level is
achieved. If you further try to increase the drive power you will now see the output power become rather
saturated, from these adjustments,
(Maximum ALC voltage produced is -10V when the amplifier output is over 200W.)
RE AR VI EW( Upper Ri ght Cor ner) ALC VO LU M E
AL C AD J
AL C O U T m ax. AL C O U T min.
ST BY
To Tr anscei ver
AL C
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