User's Manual
8 3 6 A 2 k W UHF Tr a nslat or , I nt erna lly Diple x ed Syst e m D e scr iption
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The 836A is a com plet e 2 kW UHF Solid St at e I nt ernally Diplexed Television Translat or which
operates at a nom inal Visual Out put Power of 2000 Wat t s Peak of Sync and wit h an Average Aural
Out put Power of 200 Wat t s at an A/ V Rat io of 10 dB, 10 % Sound. The Translat or uses t he
com bined I F Output of t he Receiver Tray as t he input t o the UHF Excit er Tray.
The 836A (1078476) is functionally com prised of ( A4) t he UHF Excit er ( 1300- 1020) , (A3) t he
VHF/ UHF Receiver Tray ( 1265- 1100) , ( A5) the 4 Way Split t er Assem bly, (A6, A7, A8 & A9) four
UHF Am plifier Trays ( 1294-1112, 1294- 1113 or 1294- 1114) , (A10 & A11) two UHF Tee Assem blies,
( A12) a Hybrid Com biner, ( A13) a Bandpass Filt er, (A14) an (Opt ional) UHF Trap Filter, ( A16) a
Coupler Assem bly, (A2) an AC Dist ribut ion Assem bly ( 1276- 1200) and (A17) an ( Optional) A/ V
I nput & Rem ote I nt erface Assem bly ( 1276- 1008) or a Rem ot e I nt erface Assem bly w/ Moseley
( 1314- 1008) .
The (A3) VHF/ UHF Receiver Tray ( 1265-1100) t akes t he On Channel RF I nput, which connect s to
J5 for 75Ω or J1 for 50Ω on the rear of the Tray and generates a Modulated Diplexed I F Out put.
The Com bined I F from J4 connects to t he J6 on t he ( A4) UHF Excit er Tray ( 1265-1300) which
upconverts the signal to the On Channel Frequency Visual + Aural RF Output . The RF Out put of
the UHF Excit er at J15 is split four w ays by ( A5) t he Four Way Split t er Assem bly ( ZFSC-4- 1SMA) .
The output s of the Split t er feed t o J1 on the four (A6, A7, A8 & A9) UHF Am plifier Trays. The RF
output s of the ( A8 & A9) UHF Am plifier Trays are com bined in the ( A11) UHF Tee Assem bly and the
output s of the ( A6 & A7) UHF Am plifier Trays are com bined in the ( A10) UHF Tee Assem bly. The
Com bined Out puts of each UHF Tee are com bined in (A12) a Hybrid Com biner. A 500 Wat t Dum m y
Load ( A18) is connect ed to the Hybrid Com biner and provides Transm it t er prot ect ion, using the
Therm al Swit ch ( A18-A1), in case of m isalignm ent in the com bining or a m alfunct ion in the UHF
Am plifier Trays which causes overtem perat ure. The RF out put of the Hybrid Com biner is connect ed
to ( A13) a Bandpass Filt er, and then eit her direct ly t o ( A16) an Output Coupler Assem bly or
through ( A14) an ( Optional) One Section or Two Sect ion UHF Trap Filter. The 7/ 8” RF Out put at
J2 of the Coupler is the out put of the Translat or. The ( A16) 7/ 8" Coupler Assem bly supplies a
Forward Power Sam ple and a Reflect ed Power Sam ple to the Visual/ Aural Metering Board locat ed in
the UHF Excit er. The Sam ples are peak det ected and wired t o t he Transm it t er Cont rol Board which
connect s t he Visual, Aural and Reflect ed Power Out put Sam ples t o t he front panel Met er on the
Excit er for m onit oring.
The Com bined Visual I F + Aural I F I nput ( 0 dBm Typical) from the Receiver Tray connects t o J6 on
the UHF Excit er Tray. The Com bined I F is cabled t o the (A8) ALC Board ( 1265-1305) which gives
the operat or control over the out put power level of t he Translat or by adj ust ing the level of t he
com bined I F Signal. The I F Signal is fed out of t he ALC Board t o ( A9) an I F Phase Correct or Board
( 1227- 1250) that is adj usted for best signal and then back t o t he ALC Board.
Upcon ver t er Sect ion
The output of t he ALC Board ( 0 dBm ) connects t o ( A11) the UHF Upconvert er Board ( 1265-1310),
located in t he Upconvert er Sect ion, which t akes t he L.O. and het erodynes it wit h t he Com bined I F,
that is t hen filtered to produce t he RF On Channel Out put. The crystal frequency needed to
generate the L.O. is produced by (A14-A1) t he Channel Oscillat or Board ( 1145-1201) located in
( A14) t he Channel Oscillat or Assem bly ( 1145- 1202) or if the Opt ional FSK I dentifier Kit is
purchased, by t he VCXO Channel Oscillator Board (1145-1204) located in t he VCXO Channel
Oscillat or Assem bly ( 1145-1206) . The Cryst al Frequency (+ 5 dBm ) is m ult iplied 8 t im es by ( A15-
A1) t he x8 Multiplier Board (1227-1002) , locat ed in ( A15) t he x8 Mult iplier Enclosure ( 1265- 1347) ,
which produces t he L.O. Signal at the proper frequency ( + 16 dBm ) needed in the upconversion
process t hat takes place on t he UHF Upconvert er Board. The L.O. is filtered by ( A16) a UHF Filt er
( 1007- 1101) before it is applied t o the UHF Upconvert er Board. The L.O. is m ixed with the I F to
produce an On Channel RF Output t hat is filt ered by ( A12) a UHF Filt er ( 1007- 1101) and connect ed
back to t he Upconvert er Board. The RF is connected through an AGC circuit and is am plified
before it is at tached t o the out put of the board.