Instruction Manual
21
Initial Operation
For personal and equipment safety, double-check all wiring and connections () before
turning power on. After verifying all power supply and amplifier connections, follow the
procedures below:
Place the MULTIMETER switch (fig. 2, ref. 6) in the HV position. The multimeter is the
right-side scale on the panel meter (fig. 2, ref. 1), and reads on the 0-70 right scale
bottom. Find 50 on the scale. HV reading should be approximately 50 volts whenever
the amplifier is ON. Any voltage above the Forward arc crossing is unsafe.
Place the ALC SET control (fig. 2, ref. 4) full clockwise (10 on knob scale). This sets
ALC to engage at maximum possible power, which effectively will disable the ALC for
initial testing.
With the STANDBY/OPERATE switch (fig. 2, ref. 7) on STANDBY, turn the power
switch (ref. 8) ON.
There will be a short delayed “click” from the power supply. HV (fig. 2, ref. 1) should
immediately rise to near full scale after the “click”. The meter and the appropriate BAND
LED (fig. 2, ref. 3) should illuminate.
The multimeter’s HV scale (fig.2, ref 1, lower right scale arc) should indicate
approximately 50 volts. Any voltage above the Forward arc crossing is unsafe.
Rotate the BAND switch (fig.2, ref 2 and 3) through all positions. The appropriate BAND
LED will illuminate, band-filter relays will audibly switch when moving between 160 and
80 meters, 80 and 40 meters, 40 and 30 meters, 20 and 17meters, 15 and 12 meters,
and between 10 and 6 meter selector positions. There should be no filter change
moving between 30 and 20, 17 and 15, or 12 and 10-meter selections since these band
groups share a common filter in each pair.
Set the BAND switch (fig. 2, ref. 2) to a band where you have a good 50 ohm high-
power load connected.
Change the meter switch (fig. 2, ref. 6) to REF. In this position, the multimeter indicates
PEP reflected power.
The next objective is to have a steady unmodulated low-power carrier. With no
modulation in the FM, AM, RTTY, or CW mode, and with the amplifier still on standby,
adjust the exciter’s power to about ten watts. Verify your radio is supplying reduced
power, ideally around 10-20 watts carrier (not critical), and that VSWR of the antenna
system or load is low. There should be almost no deflection on the reflected power
scale (Figure 2, ref. 1) with the MULTIMETER switch in the REF position. If the meter
indicates noticeable reflected power, check the RF cables or antenna system.
Reminder: You cannot use a tuner in your radio or between your radio and this
amplifier to match the antenna system. Any antenna matching must be between
the amplifier and the antenna, and the antenna tuner and everything else
connected beyond the amplifier must conservatively handle 600 watts of both
carrier and peak envelope power.