Alpha 9500 HF Linear Amplifier Operating Manual Alpha Radio Products
Operating the Amplifier Product Release 1
DOCNUMBER 9500
Document Issue 1, Revision 7
Page 6–2 June 2009
66
•
If the value is <3300 V, check your outlet, the wiring of the plug, and
the grounding of the equipment in your shack. If you have variable or
unstable power, you can force the amplifier to always choose a
particular tap setting. For information on how to force tap selection,
contact ALPHA technical support.
•
If the value is >3800 V, ensure that the correct primary tap is being
selected. If auto-tap-selection is disabled, try enabling it. If the
highest tap is being used, your line voltage is likely >250V; talk to
your power company about reducing it.
To return to the countdown display, press the FLT (Fault) button.
NOTE During warmup and operation, do not press the MEMORY/AUTO
button. The amplifier always performs automatic frequency detection,
band-tuning, and antenna selection independently from this button.
Rather, use this button to assist with initial tune and load settings as
described in
Section 6.4, “Tune the Amplifier,” page 6–5.
Step 3 Push the OPER button and select the correct antenna.
Step 4 Key the amplifier by putting the transmitter into transmit mode (State 5:
keyed, no RF).
NOTE: For information about amplifier states and what it means to
key the amplifier, see
6.3, “Put the Amplifier into the Desired
State,” page 6–3.
Step 5 Apply RF.
When the amplifier is keyed and RF is applied, the following sequence
occurs automatically:
1. The mains controller on the amplifier counts the frequency and jumps
to the correct band switch position and frequency segment.
2. The antenna is set to the last one used for that frequency on that
memory bank (Default, User 1, or User 2).
3. The tune and load capacitors are set to the saved values for that band
segment.
This is the normal functioning of the amplifier and no other user
intervention is required.
Step 6 Monitor the grid current.
The amplifier operates in Class AB2 when delivering maximum output
power consistent with excellent linearity. A small amount of grid current
flows, which you can monitor via the grid-current bar graph. As overdrive
approaches, grid current increases rapidly and the red grid LEDs become
illuminated.
To Next Page
Loading...
