I N STRUCTI ON M AN UAL 836A 2000 WATT UHF TRANSLATOR AXCERA, LLC 103 FREEDOM DRI VE P.O. BOX 525 LAWRENCE, PA 15055- 0525 USA ( 724) 873- 8100 • FAX ( 724) 873- 8105 w w w . ax cer a. com • info@ax cer a.
8 3 6 A 2 k W UH F Television Tra nsla t or, I nt erna lly D iple x e d 1. I nt roduct ion: 2. Syst em - 836A: A. B. C. D. E. F. G. H. I. Syst em Descript ion Specificat ions Sit e Considerat ions Unpacking and I nst allat ion Procedures Translat or Set Up and Operat ion Procedure Met er s, Sw it ches and I ndicat or s Translat or Det aile d Alignm ent Procedure Rem ot e Cont rol I nt erface Connect ions Drawings: 1. 2. 3. 3. Ta ble of Con t e n t s 2 kW Translat or Block Diagram . . . . . . . . . .
8 3 6 A 2 k W UH F Television Tra nsla t or, I nt erna lly D iple x e d 8. Ta ble of Con t e n t s Maint enance: This sect ion cont ains inform at ion on t he operat ion and m aint enance of t he 836A. This sect ion cont ains inform at ion on t he Plugs, Jacks, Socket s and Pins t hat m ake up t he Harness and Cable Assem blies in t he 836A.
F WARNING!!! × HIGH VOLTAGE Ø DO NOT ATTEMPT TO REPAIR OR TROUBLESHOOT THIS EQUIPMENT UNLESS YOU ARE FAMILIAR WITH ITS OPERATION AND EXPERIENCED IN SERVICING HIGH VOLTAGE EQUIPMENT. LETHAL VOLTAGES ARE PRESENT WHEN POWER IS APPLIED TO THIS SYSTEM. IF POSSIBLE, TURN OFF POWER BEFORE MAKING ADJUSTMENTS TO THE SYSTEM. « RADIO FREQUENCY RADIATION HAZARD « MICROWAVE AMPLIFIERS AND TUBES GENERATE HAZARDOUS RF RADIATION WHICH CAN CAUSE SEVERE INJURY INCLUDING CATARACTS, WHICH CAN RESULT IN BLINDNESS.
EM ERGEN CY FI RST AI D I N STRUCTI ON S Per sonnel engaged in t he inst allat ion, oper at ion, or m aint enance of t his equipm ent ar e ur ged t o becom e fam iliar w it h t he follow ing r ules bot h in t heor y and pr act ice. I t is t he dut y of all oper at ing per sonnel t o be pr epar ed t o giv e adequat e Em er gency Fir st Aid and t her eby pr ev ent av oidable loss of life. RESCUE BREATHING 1. Find out if t he per son is br eat hing.
LIMITED WARRANTY ONE YEAR Seller warrant s each new product m anufact ured and sold by Seller against defect s in m at erial and workm anship under norm al use and service, for a period of one ( 1) year from t he dat e of shipm ent from Seller's plant , when oper at ed in accor dance w it h Seller 's oper at ing inst r uct ions. This w ar r ant y shall not apply t o t ubes, fuses, bat t er ies, or bulbs.
) MATERIAL RETURN PROCEDURE In order to efficiently handle equipment or components returned for repair or sent out on loan, Axcera requests that each returned item be accompanied by a Material Return Authorization Number (MRA#). To obtain an MRA follow the procedures below: p Call Axcera Customer Service at (724)-873-8100 or FAX (724) 873-8105 p A Service Engineer will provide you with an MRA# p Write the MRA# on the packing list or in the case of repairs, a note describing the reason for return.
. PROPER PACKING OF MATERIALS When returning materials to Axcera, it is extremely important to pack them properly. Due to the delicate nature of components contained within the equipment, major damage can occur without proper packing. Please adhere to the following guidelines when returning materials. o Save the boxes that the transmitter is shipped in. Each tray is sent double boxed and enclosed in foam padding. Use the same packing method when returning materials.
dBm, dBw, dBmV, dBµ µ V, AND VOLTAGE EXPRESSED IN WATTS 50 ohm system WATTS 1,000,000,000,000 100,000,000,000 10,000,000,000 1,000,000,000 100,000,000 10,000,000 1,000,000 100,000 10,000 1,000 100 50 20 10 1 0.1 0.01 0.001 0.0001 0.00001 0.000001 0.0000001 0.00000001 0.000000001 0.0000000001 0.00000000001 0.
USEFUL CONVERSION FACTORS TO CONVERT FROM TO MULTIPLY BY mile (US statute) kilometer (km) 1.609347 inch (in) millimeter (mm) 25.4 inch (in) centimeter (cm) 2.54 inch (in) meter (m) 0.0254 foot (ft) meter (m) 0.3048 yard (yd) meter (m) 0.9144 mile per hour (mph) kilometer per hour(km/hr) 1.60934 mile per hour (mph) meter per second (m/s) 0.44704 pound (lb) kilogram (kg) 0.4535924 gallon (gal) liter 3.7854118 U.S. liquid (One U.S. gallon equals 0.
ABBREVIATIONS/ACRONYMS AC Alternating Current PCB Printed circuit board AFC Automatic Frequency Control QAM Quadrature Amplitude Modulation ALC Automatic Level Control AM Amplitude modulation AGC Automatic Gain Control AWG American wire gauge BER Bit Error Rate BW Bandwidth DC Direct Current D/A Digital to analog dB Decibel dBm Decibel referenced to 1 milliwatt dBmV Decibel referenced to 1 millivolt dBw Decibel referenced to 1 watt FEC Forward Error Correction FM Frequency
RETURN LOSS VS. VSWR 0 -10 -20 R E T U R N L O S S -30 dB -40 -50 -60 -70 1.001 1.01 1.1 VSWR 2.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Syst e m D e scr ipt ion The 836A is a com plet e 2 kW UHF Solid St at e I nt ernally Diplexed Television Translat or which operat es at a nom inal Visual Out put Pow er of 2000 Wat t s Peak of Sync and w it h an Average Aural Out put Pow er 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 Out put of t he Receiver Tr ay as t he input t o t he UHF Excit er Tr ay.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Syst e m D e scr ipt ion Out put RF Se ct ion The RF Out put of t he UHF Excit er is split four ways in ( A5) t he 4 Way Power Split t er Assem bly ( ZFSC- 4- 1SMA) . The out put s of t he Split t er feed t he four ( A6, A7, A8 & A9) UHF Am plifier Trays which am plify t he RF signals t o approxim at ely 600 Wat t s each.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Syst e m D e scr ipt ion Ope r a t ion of t he Tr a nsla t or The Tr anslat or needs an AC input of 220 VAC at 80 Am ps connect ed t o it in or der t o oper at e. The 220 VAC I nput connect s t o t he Term inal Block ( TB1) , locat ed in t he upper right rear of t he Cabinet , t hat is part of ( A2) t he AC Dist ribut ion Panel ( 1276- 1200) .
UHF Solid State Transmitter / Translator 825A / 827A - 500W 830A / 832A - 1kW 834A / 836A - 2kW These products represent the state of the art in solid state UHF transmitters. High performance, redundancy, and simplicity are combined in a very compact unit. Multiplexed aural/visual amplification is achieved with very good intermodulation performance, thanks to highly linear amplifiers and extensive correction capability.
UHF Solid State Transmitter / Translator UHF Solid State Transmitter / Translator Exciter The exciter, designed and built by Axcera, contains the circuitry to convert the input video and audio signals to a combined, modulated RF signal which drives the power amplifiers. In the translator version, a receiver replaces the modulator circuits to accept an off air RF input and convert it to IF.
UHF Solid State Transmitter / Translator UHF Solid State Transmitter / Translator ■ Utilizes 100% solid state circuitry for high reliability and low maintenance costs ■ 1kW and 2kW configured with parallel high gain amplifiers, separate power supplies and cooling for excellent redundancy, including driver stages ■ Packaged in a compact design, completely contained in a single rack - including output filters! ■ Provides standard ±1 kHz frequency stability for stations with an offset frequency ■ Configured
UHF Solid State Transmitter / Translator Visual Performance Power Output (Peak) Output Impedance Output Connector Frequency Range* Carrier Stability (Transmitters) 500, 1000, 2000 W 50 ohms 7/8" EIA 470 to 806 MHz ±1 kHz (standard) ±350 Hz (optional) Frequency Translation Stability ±1 kHz (standard) (Translators) ±350 Hz (optional) Regulation of RF Output Power 3% Output Variation (over 1 frame) 2% Sideband Response (System M/N-others on request) -1.25 MHz and below -20 dB -0.75 to -0.5 MHz +0.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Sit e Conside r a t ions There are special considerat ions t hat need t o be m ade before inst alling t he 836A and t his sect ion will help you plan ahead. The Translat or requires an AC I nput Line of 220 VAC wit h a rat ing of 80 Am ps. Check t hat t he sit e has t he volt age requirem ent needed. 836A is designed and built t o provide long life wit h a m inim um of m aint enance.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Sit e Conside r a t ions condensat ion in Tr anslat or s. For t ube t ype Tr anslat or s t his can be especially ser ious if t he condensat ion for m s in t he t ube cavit y and cr eat es dam aging ar cs. A few caut ions should be observed concerning an air condit ioning syst em . 1. Air condit ioners have an ARI nom inal cooling capacit y rat ing.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Sit e Conside r a t ions 9. A cont rolled air bypass syst em m ust be inst alled t o prevent t he t em perat ure in t he room from falling below 40 degrees F during Translat or operat ion. 10. The blow er should have t w o speeds, w hich are t herm ost at ically cont rolled, and int erlocked w it h t he Translat or. 11.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Unpa ck ing a nd I nst a lla t ion Air condit ioning and any relat ed heat exhaust duct s should be in place before cont inuing wit h t he inst allat ion of t he Translat or. Please inspect t he Cabinet and all ot her m at erial t horoughly upon arrival. Ax cer a cer t ifies t hat upon leaving our facilit y t he equipm ent was undam aged and in proper working order.
8 3 6 A 2 k W UH F Tra nsla t or, I nt erna lly Diplex ed Unpa ck ing a nd I nst a lla t ion Rem ot e I nt er face Panel m ount ed on t he Rear Top of t he Tr anslat or . A plug is connect ed t o Jack ( J11) , wit h Pins 23 & 24 j um pered t oget her on t he UHF Excit er or t o Jack ( J9) ,wit h Pins 21 & 22 j um pered t oget her on t he ( Opt ional) Rem ot e I nt erface Assem bly, which are 37 Posit ion " D" Connect or s t hat pr ovide t he I nt er lock for t he Tr anslat or .
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Se t Up a nd Ope r a t ion Pr oce dur e I nit ially t he Translat or should be t urned on wit h t he RF Out put at ( A11) t he Coupler Assem bly t erm inat ed int o a dum m y load of at least 2000 Wat t s. I f a load is not av ailable, check t hat t he Out put of t he Coupler Assem bly is connect ed t o t he Ant enna for your Syst em .
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Typica l Ope r a t iona l Re a dings UH F Ex cit e r ALC = .8 VDC. % Ex cit er = Th e lev el is as n eeded t o at t ain 1 0 0 % ou t pu t pow er fr om t h e Tr an sm it t er . % Reflect ed = < 5 % % Visu al Pow er = 1 0 0 % % Au r al Pow er = 1 0 0 % UH F Am plifie r Tr a ys ( A6) ( A7) AGC Volt age = 1 t o 2 VDC. AGC Volt age = 1 t o 2 VDC. % Reflect ed = < 5 % w it h bot h Tr ay s oper at in g. < 5 0 % w it h on e Tr ay oper at in g.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d M e t e r s, Sw it ch e s, I n dica t or s a n d Sa m ple s UH F Ex cit e r Tr a y: Nam e Funct ion “ M e t e r ing” M e t e r ( A4 - A1 8 ) Reads pow er in t erm s of a percent age of t he calibrat ed Out put Pow er level on t he upper scale. The Volt age Level is read on one of t he bot t om t w o scales. A full scale r eading on t he t op scale is 100% , which is equivalent t o t he full rat ed 2000 Wat t s Peak of Sync Visual.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d M e t e r s, Sw it ch e s, I n dica t or s a n d Sa m ple s Transm it t er is cont rolled by t he Operat or using t he front panel Operat e/ St andby Sw it ch or by rem ot e cont rol. Power Adj ust ( R1) Th e 5 kΩ Pot A20 set s t he ALC Level on t he ALC Boar d w hich set s t he out put pow er of t he Tr ansm it t er .
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d M e t e r s, Sw it ch e s, I n dica t or s a n d Sa m ple s Power. Also reads % Reflect ed Power, Power Supply Volt age Levels and AGC Volt age Levels. Sw it ch ( S2) , Met er Select s t he desired % Pow er or t he Volt age reading. % Out put Pw r Reads t he % Out put Pow er of t he Tray, 100% = 600 Wat t s Peak of Sync Visual + Aural, on t op scale.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d M e t e r s, Sw it ch e s, I n dica t or s a n d Sa m ple s “ Con t r ol” Adj u st m e n t s Phase ( A10- R5) Adj ust s t he Phase of t he RF Out put approxim at ely 70°. Gain ( A11- R6) Adj ust t he gain of t he RF Out put when t he Am plifier cont rol Board is in t he AGC Mode. “ Sa m ple ” Module O/ P (0 dBm ) A Sam ple of t he Com bined Out put of t he four Dual St age Am plifier Boards t aken from t he Dual Peak Det ect or Board.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure This Translat or was aligned at t he fact ory and should require no addit ional alignm ent t o achieve norm al operat ion. Check t hat t he RF Out put at J2 of ( A16) t he Coupler of t he Translat or is t erm inat ed int o a dum m y load of at least 2000 Wat t s.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure t he Pow er Adj ust Gain Pot , locat ed on t he Front Panel of t he UHF Excit er Tray, t o obt ain + 0.8 VDC on t he Front Panel Met er in t he ALC Posit ion. On t he ALC Board ( 1265- 1305) , m ove t he Jum per W3 on J6 t o t he Manual Posit ion, bet ween Pins 2 & 3, and adj ust R87 on t he ALC Board for + 0.8 VDC on t he Front Panel Met er in t he ALC Posit ion.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure Lin e a r it y Cor r e ct or Adj u st m e n t The I F linear it y cor r ect ion funct ion consist s of t hr ee non- linear cascaded st ages, each hav ing adj ust able m agnit ude and t hreshold or cut - in point s locat ed on t he ALC Board. The t hreshold adj ust m ent det erm ines at w hat I F signal level t he corresponding correct or st age begins t o increase gain.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure The follow ing pr ocedur e w as com plet ed at t he fact or y and should only be follow ed 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 Tr anslat or t o Oper at e and adj ust t he Gain Pot on each Tr ay for 25% Out put Pow er . Adj ust t he Phase Cont rol CW on t he Left UHF Am plifier Tray.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure Power posit ion. At t his 20% Reference Power reading, t he VSWR LED m ount ed on t he front panel of t he Excit er should be illum inat ed. I f not adj ust R22 on t he Transm it t er Cont rol Board unt il t he VSWR LED j ust t urns On. Turn t he Power Adj ust pot slight ly CCW and t he LED should go out , t urn t he pot CW unt il t he LED j ust t ur ns On. The Reflect ed Out put Pow er is now calibr at ed.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure - 4.5 MHz and + 9 MHz from FV at t he t op and bot t om r espect iv ely of t he left hand side of t he Bandpass Filt er, looking from t he rear of t he Cabinet . Refer t o t he Bandpass Filt er Drawing for t he locat ion of t he adj ust m ent s.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D e t a ile d Alignm ent Procedure w it h t his pr ocedur e is t he lengt h of t he Cent er Conduct or inside t he Tr ap Filt er . The gap bet w een t he Trap and t he Main Line should not be changed. Moving only t he I nner or t he Out er Conduct ors by it self w ill effect t he Gap and t he Not ch dept h. To effect t h e Not ch Dept h Only, bot h sect ions will have t o be m oved.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Funct ion Re m ot e Cont r ol I nt e r fa ce Conne ct ions Rem ot e Ja ck / Pin N o. I nt e r fa ce Type The Rem ot e Connect ions, as list ed below, are m ade if t he Opt ional ( A17) A/ V I nput & Rem ot e I nt erface Assem bly ( 1276- 1008) is n ot pr e se n t in your Syst em . Refer t o t he I nt er connect Drawing ( 1276- 8000) for t he proper Pin Rem ot e Connect ions.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Funct ion Re m ot e Cont r ol I nt e r fa ce Conne ct ions Rem ot e Ja ck / Pin N o.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Funct ion Re m ot e Cont r ol I nt e r fa ce Conne ct ions Rem ot e Ja ck / Pin N o. I nt e r fa ce Type U H F Ex cit e r Tr anslat or Enable I nt er lock Translat or Enable I nt erlock Rt n. J9- 21 J9- 22 J9- 21 & 22 m ust be jum pered t oget her for Norm al Operat ion. ( 1176- 1038) Jum per Jack is used. Translat or St andby ( Disable) Tr anslat or St andby/ Oper at e Rt n.
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Funct ion Re m ot e Cont r ol I nt e r fa ce Conne ct ions Rem ot e Ja ck / Pin N o.
I TS- 8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D r a w ing List ( Suba sse m blie s) VHF L.O. Filt er, High Band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1005- 1208 Schem at ic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I TS- 8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D r a w ing List ( Suba sse m blie s) x8 Multiplier Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1227- 1002 Schem at ic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I TS- 8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d D r a w ing List ( Suba sse m blie s) Transm it t er Cont rol Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1265- 1311 Schem at ic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d M a in t e n a n ce The 836A is designed wit h com ponent s t hat require lit t le or no periodic m aint enance except for t he r out ine cleaning of t he Fans and fr ont panels of t he Tr ays. The am ount and t im e int erval bet ween cleanings depends on t he condit ions wit hin t he Transm it t er r oom . While t he elect r onics have been designed t o funct ion even if cover ed w it h dust .
8 3 6 A 2 k W UH F Translat or, I nt ernally D iple x e d Log Re por t She e t U H F Ex cit e r % Aur al Pow er ( 0 - 1 0 0 ) = _ _ _ _ _ _ _ _ _ _ _ _ _ % ____________% % Visual Pow er (0 - 100) % Reflect ed ( 0 - 100) = _____________% % Ex cit er ( 0 - 100) = ______________% = ALC ( 0 - 1 V) = _________________V UH F Am plifie r Tr a ys ( A6) ( A7) AGC Volt age = _ _ _ _ _ _ _ _ _ V AGC Volt age = _ _ _ _ _ _ _ _ _ V % Reflect ed = _________% % Reflect ed = _________% % Ou t pu t For w
M a int e na nce Bulle t in Topic: Flanged RF Am plifier Transist ors This Bullet in covers t he procedure for t he replacem ent of Flanged RF Am plifier Transist ors. These t ransist ors, bot h Bipolar and FET t ypes, are m ount ed direct ly t o heat sink assem blies using t wo m ount ing screw s. This cat egory of t ransist or covers a num ber of different t ypes and part num bers, but t he inform at ion covered in t his bullet in is of a general nat ure and applies t o all such t r ansist or s.
M a int e na nce Bulle t in Topic: Flanged RF Am plifier Transist ors St ep 1. Ca u t ion : I f t he device being replaced is a GaAs FET, before applying t he Posit ive Volt age t o t he Dev ice check t hat t he Negat iv e Bias Volt age is applied t o t he Dev ice. 9. The am ount of St at ic Collect or or Drain Current is calculat ed using Ohm 's Law ( I = E\ R) . Measure t he volt age drop across t he Collect or or Drain Resist or, one lead on each side of t he Resist or.