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~-4 V, and Yaesu
may need 0~-5 V range.. Kenwood may need -6~-8 V maximum. Check your
transceiver manual.
9-1
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.
9-2
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 -10 V when the amplifier output is over 200
W.)
Min Max
To Transceiver
16
