SRK FMA300, Руководство пользователя

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FMA 300 Manual
 2003 SRK Electronics Pty Ltd
4.5
Setting Channel Frequency
See FMX25 manual. Note that it is advisable to reduce RF power to zero before changing
frequency, then ramping power back up at the new frequency.
4.6
Setting audio gain
See FMX25 manual.
4.7
Selecting pre-emphasis and input impedance.
See FMX25 manual.
4.8
Enabling/disabling stereo.
See FMX25 manual.
4.9
SCA option.
See FMX25 manual.
4.10
Protection
The FMA300 incorporates a number of protective features that make it extremely rugged.
If the reflected power from the antenna exceeds 30W then the output RF power will be
automatically reduced to bring the reflected power back to 30W. Under this condition the
FMA300 will continue to function, albeit at a reduced output power, indefinitely until the
reflected power reduces. The amplifier alarm LED “HIGH SWR” will light.
If the temperature of the RF amplifier becomes excessive (>85ºC), then the RF output power
will be reduced to zero until the amplifier temperature falls to an acceptable level. During this
time the amplifier alarm LED “HIGH TEMPERATURE” will light.
If the RF output power exceeds 330W then the amplifier will limit power to about 330W. The
amplifier alarm LED “HIGH O/P POWER” will light.
If the RF input power exceeds about 10W then the amplifier will shut down until the RF power
drops to less than 4W. During this time the amplifier alarm LED “HIGH I/P POWER” will light.
See also the relevant sections of the FMX25 manual.
All error conditions are recoverable automatically once the cause of the error has been
removed. No user intervention is required.