Comtech EF Data CPA - Manual (Page 120)

CPA C-Band Indoor Solid State Power Amplifier Revision 1
Appendix A MN/CPA-IN.IOM
A–4
Issue Possible Cause(s) Solution(s)
No RF output or ≤ output
level.
1. Mute function activated.
2. Amplification = Off feature activated.
3. Large customer attenuation values
selected.
4. Input power level not correct.
5. Faulty input connections from 9V
supplies.
6. Fault SSPA control cable or
connection.
1. Check the Configuration menu to determine if
mute function has been activated. Mute = On
Means that the unit is muted. Turn Mute
feature to Off to allow RF amplification of the
input signal.
2. The Amplification = Off feature allows for
lower current draw from the prime power
source under standby conditions. To obtain
RF output, ensure that this feature is set to
Amplification = On.
3. Check the Attenuation = XX setting in the
Configuration menu. Lower value to get more
gain.
4. Use the input sample port on the front panel
to determine that the input power level is as
specified. Remove and replace the input
cable.
5. Use the Monitor menu to check the internal
level of the PS1 and PS2. The levels should
be near 9V. If not correct, use a voltmeter to
measure the voltage where the #8 wires enter
the amplifier unit. With Unit Off, tighten
connections if necessary.
6. Check the 25-pin ribbon cable connection at
the amplifier module and at AS/0200 PCB.
Tighten as necessary.
Failed SSPA amplifier
module.
This can usually be determined by using
the Monitor menu to check the DC
current levels being drawn by each
transistor inside the amplifier module.
Any transistor (QX) current that is 50%
more or less than normal would probably
indicate a failure.
Nominal Values:
Q1 =
20mA
Q2 = 100 mA
Q3, Q4 = 1.0 A
Q5, Q6, Q7 = 2.0 A
Q8 to Q18 = 2.25 A
There are no user serviceable parts inside the
amplifier module. Return to factory for repair.
No remote control
communication
1. Incorrect cable connections.
2. Improper communication settings
between ISSPA and controlling
terminal.
3. Entry mode of unit set to LOCAL.
1. Ensure cable is connected properly.
2. Check settings of ISSPA along with remote
control terminal software.
3. Change entry mode setting in Configuration
menu to Remote.