User's Manual
8 3 6 A 2 k W UHF Tr a nslat or , I nt erna lly Diple x ed Det ailed Alignm e n t Pr oce dur e
- Page 4 of 7 -
The following procedure was com plet ed at t he fact ory and should only be followed if one of t he
UHF Am plifier Trays is replaced.
Preset t he Phase and Gain pot ent iom et er locat ed on each UHF Am plifier Tray Full CCW. Swit ch t he
Translat or t o Operat e and adj ust t he Gain Pot on each Tray for 25% Output Power. Adj ust the
Phase Cont rol CW on the Left UHF Am plifier Tray. I f the % Visual Out put Power goes UP, cont inue
to adjust unt il eit her t he Peak is reached or t he End of Travel is reached. I f the % Output Power
goes Down, Reset t he Phase Cont rol on t he UHF Am plifier Tray Fully CCW and repeat t he above
procedure w it h the Phase Cont rol of t he ot her Am plifier Tray.
I f the End of Travel is reached on the Phase Adj ust , Reset t he Phase Cont rol CCW and add a 2"
length of Cable t o the out put of t he ( A5) Split ter Module w hich connects t o t he effected UHF
Am plifier Tray at J1. Readj ust t he Phase of t hat Tray unt il a Peak is reached or until End of Travel
is achieved. I f End of Travel is reached, repeat the above procedure replacing the 2" lengt h cable
wit h a 4" length of cable. Once a Peak is reached, m ove t he Phase Cont rol, t hat is Full CCW, Up 2
Turns and re- peak using the Phase Cont rol located on t he other Tray. This allows both Trays t o
have som e range of adj ust m ent.
Adj ust the Gain of bot h UHF Am plifier Trays for 90% Tray Output Power. Readj ust each Phase
Cont rol to Peak t he Com bined Out put , the Phase should only have been effect ed slightly. There
should be a definite Peak t hat is achieved while adj ust ing the Phase of each Tray though it m ay
take a few Turns t o not ice a change. Raise or Lower t he Out put Power of each Tray t o achieve
100% Out put Power. The Out put Power of each Tray should be 90% - 100% .
Calibrat ion of t he Forw a r d Out put Pow er Level of t he Tr a nslat or
N ot e: - Perform the following only if t he power calibrat ion is suspect .
Switch t he Translat or t o St andby and preset R51, Aural Null pot, locat ed on the Visual/ Aural
Met ering Board ( 1265-1309), full CCW. Adj ust R48, t he Null Offset pot, locat ed on the Visual/ Aural
Met ering Board, for 0% Visual Out put . Do the following adj ust m ent s wit h no Aural present, by
rem oving the Aural from the RF I nput Test Signal. Connect a Sync and Black Test Signal to the
I nput of t he UHF Excit er Tray. Swit ch the Translat or t o Operat e.
Calibrat ion of t he Forw a r d Out put Pow er Level of t he Tr a nslat or.- Continued
Next Set t he Translat or up for the appropriat e Average Out put Power Level. ( Sync + Black 0 I RE
Set up Wat t m et er = 1190 Wat t s) . ( Sync + Black 7.5 I RE Set up Wat t m et er = 1090 Wat ts).
N ote : Must have 40 I RE Unit s of Sync. Adjust R28, Visual Calibration, locat ed on (A19) t he
Visual/ Aural Met ering Board ( 1265-1309) for 100% on the front panel m et er in t he % Visual Out put
Posit ion.
With t he Spectrum Analyzer set t o Zero Span Mode, obt ain a peak reference on the screen.
Reinsert the Aural t o the RF input t est Signal. While in t he Visual Out put Power posit ion, adjust L3
for m inim um visual power reading. Turn t he power adj ust pot on the front panel unt il t he original
peak reference level is at t ained. Peak L1 and C8 for m axim um Aural Power reading, t hen adj ust
R20 also for 100% Aural Power reading. Then swit ch t o Visual Out put Power posit ion and adj ust
R51 for 100% Visual Power.
Calibrat ion of t he Reflect e d Out put Level of t h e Translat or
Turn the Power Adjust Pot t o 20% on t he Meter in the Visual Power posit ion, check that t he
Jum per is in Manual on t he UHF Upconverter Board ( 1265- 1310) . Unt erm inate the Translator and
adj ust R39 on t he Visual/ Aural Met ering Board ( 1265-1309) for a 20% reading in the Reflect ed