User's Manual

1 1 7 B 2 0 W at t V H F H igh Band Transla t or UHF/ VHF Re ceive r Tr a y,
w / ( Optiona l) Fr equency Correct ion
Det aile d Align m ent Pr oce dur e
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( A4) Channel Oscillator Assem bly, Dual Oven ( 1145- 1202) - Continued
Contains: The ( A4- A1) Channel Oscillat or Board, Dual Oven ( 1145- 1201).
N ote : I f the Opt ional Frequency Correction Kit is purchased a VCXO Assem bly ( 1145- 1206) ,
cont aining a VCXO Board ( 1145-1204), will be used inst ead of the st andard Channel
Oscillat or Board. The adj ust m ent will be t he sam e as above except that t he frequency is
adj ust ed by m oving the Jum per W1 on Jack J6, located on the I F PLL Board (1109-1002), t o
Pins 2 & 3, Fixed Bias, and adj ust ing R15 on t he I F PLL Board for - 3 VDC at FL2 of t he VCXO
Assem bly. Move the Jum per W1 on Jack J6 to bet ween Pins 1 & 2, AFC. Connect the
Oscillat or Sam ple output , at ( J2) of the Channel Oscillat or or the Front Panel Sam ple Jack
( J9) , to a suit able Frequency Count er and tune C11, Coarse Adj ust , t o the desired
frequency. Do not re - peak C6, C18, L2 or L4 because it may change t he out put frequency.
Reconnect t he m ain out put ( J1) of the Channel Oscillat or ( + 5 dBm ) t o the input ( J1) of t he
Mult iplier Board. DS1 the Red Unlock I ndicat or, locat ed on t he I F PLL Board, should not be
lit .
( A5- A1) x8 Mult iplier Board ( 1227-1002) , x4 Multiplier Board (1227-1525) or x2 Multiplier Board
( 1227- 1524)
Mount ed in ( A5) a Mult iplier Enclosure ( 1265-1125).
During Norm al operation, the Green LED DS1, which can be seen t hrough t he access hole in the
Enclosure Assem bly, w ill be lit t o indicat e that t he L.O. is present at the out put of the x8 Multiplier
Board.
1. Connect a Spect rum Analyzer to t he Out put Jack ( J2) of the board.
2. Tune C4, C6, C10, C12, C18 and C20 on the x8 and the appropriat e caps on the other
boards for m axim um out put . Readj ust all the Capacitors to m inim ize t he sevent h and t he
nint h harm onics, they should be at least -30 dB down, wit hout affect ing t he x8 Mult iplier
Out put.
I f a Spect rum Analyzer is not available a DC voltm et er can be used as follows but t he harm onic
frequencies m ust be m inim ized to prevent int erference wit h other Channels.
1. While Monit oring each Test Point with a DC voltm eter, m axim ize t he volt age by t uning t he
Broadband Mult ipliers in the following sequence.
2. For x8 Mult iplier Board: Monitor TP1 wit h a DVM and tune C4 for m axim um . ( Typical .6 VDC)
Monitor TP2 and t une C6 and C10 for m axim um . ( Typical 1.2 VDC)
Monitor TP3 and t une C12 and C18 for m axim um . ( Typical 2 VDC)
Monitor TP4 and t une C20 for m axim um .
Re- peak C12 and C10 while m o nit oring TP4. ( Typical 3.5 VDC)
For x4 Mult iplier: Monit or TP1 wit h a DVM and t une C4 for m axim um . (Typical .6 VDC)
Monitor TP2 and t une C6 and C10 for m axim um . ( Typical 1.2 VDC)
Monitor TP3 and t une C12 for m axim um .
Re- peak C12 and C10 while m onit oring TP3. ( Typical 2 VDC)
For x2 Mult iplier: Monit or TP1 wit h a DVM and t une C4 for m axim um . (Typical .6 VDC)
Monitor TP2 and t une C6 for m axim um .
Re- peak C4 and C6 while m onitoring TP2. (Typical 1.2 VDC)
The Green LED DS1 should be lit which indicates that t he L.O. is present at the Output Jack J2 of
the Mult iplier Board. The output of the Mult iplier at J2 is connect ed t o ( A6) a UHF or VHF Filter.