Specifications

9
DOCNUMBER 9500
Document Issue 1, Revision 7
June 2009 Page 9–9
Alpha Radio Products Alpha 9500 HF Linear Amplifier Operating Manual
Product Release 1 Diagnosing Faults
5. Ensure that amplifier is being operated with a tuning condition that
does not result in poor efficiency.
6. Ensure that the tube standing bias (keyed, with no RF) is not greater
than 500 mA. Key the amplifier with the meter set to Ip to make this
measurement. If Ip is greater than 500 mA, then there may be a
problem in the cathode bias circuitry, on the cathode board, or in the
tube itself.
Fault code 12
Description Reflected power too high.
Explanation The amplifier monitors the apparent reflected power at its output. If the
power is above the set value, currently 375 W, the amplifier goes into
BYPASS mode and attempts to clear the fault.
Resolution
•
Ensure that antennas and other equipment installed after the amplifier
were installed correctly.
Fault code 13
Description Clear over-temperature.
Explanation The amplifier has recovered from fault 11 (temperature fault).
Resolution
•
See fault 11.
Fault code 14
Description Plate voltage too high.
Explanation The plate voltage has exceeded a safe value, currently 3800 Vdc.
Resolution 1. Ensure that the AC mains voltage is correct.
2. Unplug the amplifier, plug it back in, wait for at least 30 seconds, then
turn it back on.
Fault code 15
Description Grid current too high.
Explanation The amplifier monitors the grid current and, if it exceeds a safe value for
a period of time, it goes into BYPASS mode and reports this fault. The
usual cause is too much drive for the current output loading condition. It
may represent amplifier overdrive (excessive input power) or incorrect
tune and load capacitor settings.