Data Sheet Chapter 5

4-6 kW UHF Translator Chapter 5, Detailed Alignment Procedures
837B, Rev. 0 5-3
Capacitors to minimize the
seventh and the ninth harmonics,
they should be at least -30 dB
down, without affecting the x8
Multiplier Output.
If a Spectrum Analyzer is not available a
DC voltmeter can be used as follows but
the harmonic frequencies must be
minimized to prevent interference with
other Channels.
1. While Monitoring each Test Point
with a DC voltmeter, maximize the
voltage by tuning the Broadband
Multipliers in the following
sequence.
2. For x8 Multiplier Board: Monitor
TP1 with a DVM and tune C4 for
maximum. (Typical .6 VDC)
Monitor TP2 and tune C6 and C10
for maximum. (Typical 1.2 VDC)
Monitor TP3 and tune C12 and C18
for maximum. (Typical 2 VDC)
Monitor TP4 and tune C20 for
maximum.
Re-peak C12 and C10 while
monitoring TP4. (Typical 3.5 VDC)
For x4 Multiplier: Monitor TP1 with
a DVM and tune C4 for maximum.
(Typical .6 VDC)
Monitor TP2 and tune C6 and C10
for maximum. (Typical 1.2 VDC)
Monitor TP3 and tune C12 for
maximum.
Re-peak C12 and C10 while
monitoring TP3. (Typical 2 VDC)
For x2 Multiplier: Monitor TP1 with
a DVM and tune C4 for maximum.
(Typical .6 VDC)
Monitor TP2 and tune C6 for
maximum.
Re-peak C4 and C6 while
monitoring TP2. (Typical 1.2 VDC)
The Green LED DS1 should be lit which
indicates that the L.O. is present at the
Output Jack J2 of the Multiplier Board.
The output of the Multiplier at J2 is
connected to (A6) a UHF or VHF Filter.
5.0.6 (A6) UHF Filter {(1007-1101),
VHF LB Filter (1034-1211) or VHF HB
Filter (2065-1000); Appendix D}
This filter has been factory swept at the
L.O. frequency and should not be tuned
without proper equipment. The output of
the filter (+15 dBm) is connected to J2
on (A10) the Downconverter/Filter
Assembly.
5.0.7 (A10-A1) Downconverter/
Amplifier Board (1227-1502;
Appendix D)
Mounted in: The (A10)
Downconverter/Amplifier Assembly
(1227-1505).
The Mixer contains no adjustments and
has a L.O. input of approximately +12
dBm in level applied to J2 and a -47 dBm
to -2 dBm RF input applied to J1. The
output IF level at J3 will be -55 dBm to
-10 dBm.
1. Connect a Spectrum Analyzer to
the Output Jack J3 and adjust L1,
C2 and L3 for best frequency
response.
2. Adjust C8 and R3 to notch out the
Aural IF Frequency.
The IF output at J3 (-55 dBm to -10
dBm) is fed to the IF Filter/ALC Board. If
needed a 10 dB Pad can be added to the
circuit by moving the jumpers on J4 and
J5 to the In position.
5.0.8 (A11-A1) IF Filter/ALC Board
(1227-1504; Appendix D)
Mounted in: The (A11) IF Filter/ALC
Enclosure (1265-1105).
1. Check that Switch S1, located on
the IF Filter/ALC Board, is in the
Auto ALC and that the output of
the Board at J2 is approximately 0
dBm Output, adjust R23 if needed.