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6888882V04
Overdrive Protection
The 1 kW amplifier requires a nominal drive power of approx. 40W. When operating the 1 kW
amplifier with the RM125/RM125R as driver, the input power is automatically adjusted by an
automatic level control to achieve optimal operating conditions for the amplifier.However, if the
input drive power exceeds about 80W (either because incorrect setting of the operating conditions
when using another’s vendor’s driver, incorrect connections or other possible faults), the protection
circuits prevent damage to the 1 kW amplifier by bypassing it.
High VSWR Protection
To obtain maximum forward power, the RM1200 should be connected to a low VSWR antenna system.
In case of excessive VSWR, for example, because of mismatch or damage to antenna system and/or
feed cables, the ALC circuits prevent damage by reducing the transmit power to safe values. Thus, the
RM1200 will always attempt to transmit at the maximum safe power in case of mismatch.
However, in case of excessive mismatch (for example, short or open circuit), the protection circuits
switch the 1 kW amplifier to the bypass mode: in this case, the transceiver is directly connected to the
antenna. This enables normal reception, as well as transmission, albeit at the lower power levels an
RM125/RM125R (or the transceiver used as exciter) can provide.
1 kW Amplifier Overheating Protection
Special circuits protect the 1 kW amplifier against overheating. If the temperature is too high to
enable full-power operation, the output power is automatically halved, until the temperature returns
to normal. However, if the temperature exceeds the maximum allowed limit and damage may be
caused, the protection circuits are activated and bypass the amplifier.
Imbalance Protection
When a fault, power failure or other type of failure prevents normal operation of one or more of its
internal amplification modules, the 1 kW amplifier is automatically bypassed.
PS Unit
The PS unit is a custom design that includes 6 JWS-600-48 standard power supply modules
manufactured by Lambda Inc. (see manufacturer’s manual for complete information on these
modules), contained in a compact chassis suitable for installation in 19” racks. The individual modules
automatically share the load, without any special alignments. The assembled PS unit has been
assigned a custom-design manufacturer number (YM-02-670B).
The PS unit operates on 110/220 VAC, 50/60 Hz. The AC input voltage range is automatically
switched between 110 and 220 VAC, and therefore the equipment can be used in the United States
of America as well as in other countries. Internal cooling fans enable operation over a wide range of
temperatures.
The PS unit includes two independent power supply subsystems, each pro45V to two of the
four amplification modules in the 1 kW amplifier. Protection circuits monitor each output, and
provide indications on front panel indicators in case the output voltages deviate by more than 25%
from the nominal value; if an output voltage increases beyond the maximum limit, the corresponding
power supply subsystem is turned off, to prevent damage to the 1 kW amplifier.
