GatesAir Inc. CZF Manual De Usuario

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APEX
 Exciter Incorporating FLO
 Technology
Exciter Troubleshooting Flow Charts
Maintenance and Troubleshooting
26
04s50
0.fm
03/08/07
888-2604-001
Page: 5-15
WARNING: Disconnect primary power prior to servicing.
Figure 5-8  Transmitter Has Excessive MER Troubleshooting Flow Chart
Note 4: Refer to the technical manuals for 
your transmitter to determine exact RF 
feedback connections. Chapter 2 shows 
typical RF feedback connections for 
various Harris transmitters. 
Note 1: Check Table 5-1, on page 5-10 to 
ensure diagnostics settings are correct. If 
one or more diagnostic functions are 
active, normal operation of the exciter 
and transmitter may be impaired.
Transmitter has Excessive MER, See Note 1
N
Y
These modes must be active 
for exciter to perform linear 
and non linear corrections, 
both of which effect MER
See Note 2.
Are transmitter RF samples connected to exciter? See Note 4. 
Are the HPF and PA RF samples at the correct level? See Note 
5. These samples are necessary for exciter to perform linear and 
non linear corrections, which effect MER.
Is the exciter RTAC Lin 
HPF and Non-Lin correc-
tions both in Adapt mode? 
See exciter Main Screen.
Is the Status > Adaptive 
Processing screen normal? 
See Figure 3-7, on page 3-9
N
Y
This screen shows the HPF and PA 
feedback sample levels, see Note 3. 
Are these levels out of range or 
Faulted? 
Note 3: In the Adaptive Processing status 
screen, the HPF and PA Feedbacks and 
ADT Overrange functions should show 
OK. The Yellow and Blue horizontal Bars 
represent RF sample level. They should 
fall within the middle 2/3rds of the box if 
their levels are correct. Yellow = average 
level and blue = peak level. Refer to 
Section 3.4.3, Adaptive Processing Board 
Status Screen, on page 3-9 fo
r additional 
information.
Y
N
If one or more diagnostic functions 
are active, normal operation of 
exciter may be impaired.
Y
N
Entering a waveguide type and length 
will cause RTAC to predistort the trans-
mitter output for waveguide group 
delay. This will cause the MER to 
appear bad if measured at the output of 
the transmitter high power filter.
Has a waveguide type 
been selected and a 
waveguide length been 
entered in the Setup > 
Exciter Setup screen.?
Note 6: Excessive VSWR in RF sample 
feedback path causes the exciter to correct 
for it along with the transmitter linear 
distortions. 
Noise or RF signal pickup due to a faulty 
HPF sample feedback cable will cause 
RTAC to pre correct the transmitter output 
If MER performance is still 
poor, call technical support.
System related problems can 
cause Excessive MER, see 
Note 6. 
Note 5: The correct sample input power 
range, at the at the exciter rear panel input 
connector, is -30 to 0 dBm. 
Y
N
Y
Filter Type: Use FLO BANDPASS because of the application of this exciter. Use 
Standard if the standard D-Mask filter is used. Use Asymm (asymmetrical) if the 
sharp tuned filter is used or if the group delay for the transmitter is not symmet-
rical, such as when its output is reflected through an adjacent channel sharp tuned 
filter in order to combine the two transmitters. Exciter must be restarted to make 
filter change active.
In the Setup > RTAC Setup 
screen, does the Filter Type 
choice match the HPF in the 
transmitter System?
Are the status screen 
diagnostics function all 
set to normal? SeeTable 
5-1, on page 5-10
Does the transmitter 
pass the mask test?
N