Protection Circuits - RF Power HVLA1K3 PLUS User Manual

13 PROTECTION CIRCUITS

There are many protection functions in this amplifier. If the amplifier has shut-down for some
reasons, before re-setting, correct the possible cause of the shut-down. Turn OFF the main AC
power switch once and back ON to reset. If the amplifier is operated in such a manner that
multiple protections work repeatedly over a long period of time, the amplifier can be seriously
damaged.
13.1 OVT (Over Temp)
Red LED marked "OVT" lights when the PA module reaches a high temperature and the protection
circuits has worked. Check for air intake blockages and air vent on cover. When the amplifier is in
protection mode, wait a ten minutes or more; the protection is auto-resetting.
13.2 FAULT (High antenna VSWR – Wrong Antenna/Band select)
Red LED marked "FAULT" lights when a high antenna VSWR, a wrong output antenna connector
has been selected or a wrong band situation is detected to indicate protection circuit has worked.
In case of high antenna VSWR, one solution is to reduce the drive power from the transceiver or
you may need to check that antenna VSWR is still OK. If the match cannot be corrected, and the
antenna system is not faulty, use an antenna tuner. In case of wrong band, select the correct filter
band.
If you have select a wrong band, two situations can happen:
a) if the selected filter cut-off frequency (or correspondent band) is lower than the one of the
transceiver, the protection will immediately shut-down the amplifier;
b) if the selected filter cut-off frequency (or correspondent band) is higher than the one of the
transceiver, is probable that the protection will not shut-down the amplifier but you will have an
emission full of unwanted harmonics.
13.3 OVD (Overdrive)
Red LED marked "OVD" lights when input overdrive is detected to indicate protection circuit has
worked in order to protect the input side of the power LDMOS. The solution is to reduce the input
drive power.
13.4 AC mains power supply FUSES
If either of the glass fuses (2x10A 5x20 fast type) on IEC type C14 AC mains socket fails, we
recommend do not replace the fuses and we invite you to consult the factory.
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HVLA1K3 USERS MANUAL
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Fuses Holder