User Manual

Exhibit 6 page 11 of 16
The TRI indicator will not illuminate until at least 20 W of forward power (output) is achieved. In the event
successful matching cannot be accomplished, check the BAND switch position and antenna selection. Then
check the antenna VSWR at the same drive frequency.
c) Tuning hint. A benefit of TRI is that the knob positions are virtually independent. The plate-load
resistance decreases to the right and increases to the left of the TRI center. A centered tuning
indication corresponds to the proper LOAD capacitor tuning, which presents an optimum load
resistance to the tubes.
If the LOAD knob is turned to the left with a centered TRI, there will be more gain, but less linearity. When
available drive power is insufficient or when less output but better efficiency are needed, e.g., for RTTY and
SSTV, this may be desirable. Tuning to the right of the center would lead to the opposite result, i.e., less
gain and more power attainable. Of course, this requires more drive power, more plate current, and more
plate heat, which shortens tubes expected life. Off -center tuning may also be used to compensate for line
(mains) voltage variations in order to maintain tubes efficiency. In that case, tune to the left when line
(mains) voltage is high, or tune to the right if it is low. However, where there is more than a 10% difference
from the nominal line (mains) voltage, the voltage selector inside the amplifier should be changed. See
Section 2-2 (Line Voltage Selection).
4-6 The Auto-Protection System
When any abnormal amplifier condition is detected by the auto-protection microprocessor, the risk will be
evaluated automatically and either of two levels of protection will be applied:
.
a) The first degree of protection consists of an illuminated LED warning. These include the yellow LED
warnings discussed earlier, i.e., "G1” (grid 1), "G2," (grid 2), and “IP” (plate). Operation may be
continued but the amplifier is likely to proceed to the second degree of protection, the trip.
b) The second degree of protection is a trip to the standby mode. The red “F” (fault) LED illuminates and
the amplifier automatically goes to the standby mode for several seconds. Also, the green OPER LED
goes off. The amplifier will indicate the reason for the protection trip:
- if one of the yellow (G1, G2, IP) warning LEDs is illuminated along with the “F” LED, a current limit has
been exceeded; drive power must be reduced or retuning is necessary;
- if the last red LED of the reflected-power bar-graph is illuminated together with the “F” LED, the
reflected-power limit has been exceeded; the drive must be reduced or the antenna VSWR must be
improved.
- if all three LEDs of the TRI are flashing simultaneously together with the “F” LED, the tuning is not
adjusted correctly; most likely the antenna impedance has changed and retuning is required.
Fault information normally remains on the display for several seconds while the amplifier is in the standby
mode. The auto-operate function will attempt to return the amplifier to the operate mode automatically. If
the protection trips repeatedly, the user must attend to the cause of the trip, which is typically too much drive
or antenna mismatch.
CAUTION
If all LEDs in the bar-graph area are flashing simultaneously, you must immediately switch off the amplifier
to avoid damage.
5. MAINTENANCE
If no indicator glows upon switching the amplifier on, the main fuse(s) may have blown. See Section 5-2.
5-1. Cleaning
WARNING
Do not use solvents for cleaning as they may be dangerous to you and damage amplifier surfaces and
plastic components.