Acom 1006, Руководство по эксплуатации

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Please note, that the REFLECTED POWER readings and the measured VSWR depend on the load
impedance only, and not on the amplifier tuning. If the load impedance is different from 50-Ohm pure resistive
(nominal), the REFLECTED POWER reading will always indicate reflected power presence (even at excellent
tuning). The proper tuning will allow you to operate at greater power without distortion or danger to the
amplifier.
Note also that the real OUTPUT POWER in the load is equal to the difference between the FORWARD- and
REFLECTED- readings. For instance, at a reading of FORWARD 1200W, and of REFLECTED 200W, the
real OUTPUT POWER is 1000W (into a 2.6:1 VSWR load). At very high VSWR (no antenna or badly
mismatched antenna), the FORWARD and REFLECTED readings will be almost equal, while the real
OUTPUT POWER (the difference between them) will be practically zero.
The amplifier can operate safely if the following rule is obeyed: "REFLECTED POWER < 300W". Matching is
assured for loads with VSWR up to 3:1. Nevertheless, for some loads matching is possible at even higher
VSWR. For instance, you'll get a ** REFLECTED POWER ** soft-fault protection trip at full-scale (1200W)
forward, with more than 300W reflected (900W output power), when antenna VSWR exceeds 3.5:1.
C A U T I O N
Using a feeder of coaxial cable at VSWR > 2:1 on six meters band is not recommended. At such high values
of VSWR, the high voltages, high currents, and heat associated with line losses, risk to permanently damage
your coaxial cable or antenna switch.
Update tuning periodically, even if you have not changed your antenna, in particular when a significant
change in the environment occurs (snow, ice, newly appeared or removed massive objects, any wires nearby
etc.) that would cause significant changes in the antenna impedance.
N O T E
If you use more than one antenna, it is necessary that you select the proper antenna BEFORE the next step.
Retune after selecting a different antenna, since both impedances may differ substantially (unless their
VSWR is excellent, i.e. below 1.1:1 for both).
C A U T I O N
When tuning, do not apply continuous drive longer than 3 minutes and after that pause 1-2 minutes for tube
cooling.
We recommend that you tune-up at the center frequencies of the preferred frequency segment. First preset
both capacitor knobs TUNE and LOAD to approximately middle positions.
b) Selecting the plate-load "True Resistance Indicator (TRI)" tuning aid.
You may select TRI scale in three different ways:
- By pressing simultaneously for a moment the PREV+NEXT buttons. This will insert a 6dB attenuator
between the driver and the amplifier's input (the ATT LED will light), so you'll not need to reduce the drive
power during tuning. Press the PREV+NEXT buttons momentarily again to switch the attenuator off the input
and to return to the previous display. If you would use any of the PREV or NEXT buttons only, the attenuator
would be switched off, too, but the information screen would change to respectively previous or next;
- By pressing successively either the PREV or NEXT button (whichever is nearest), until you reach the TRI
scale. This will not insert the attenuator, so you should use less than 20W drive (unless the amplifier is almost
tuned), otherwise the next step would be executed automatically;
- By simply applying a normal drive power (50-60W), while the amplifier is not yet tuned. This will
automatically invoke the TRI tuning aid and will insert the input attenuator (the ATT LED will light) after one
second of transmission. The attenuator will be switched off, and the old screen will be returned automatically,
after you release the PTT shortly. If you have meanwhile achieved a nearly good tuning, the attenuator would
not be inserted again. If the old screen was the same (TRI, selected manually earlier), you'd then be able to
precisely tune the amplifier also at nominal power, without changing drive at all. Use this hint to shorten the
tuning process duration.