Kenwood TS-820 Operating Manual

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'VOX -VA B O A RD (X5 4 - 1190- 00IThree variable resistors. VOX GAIN . ANTI VOX and D ELAY.are di r ectly mounted on a printed circu tt b oard.5V AVA B OA RD (O P TIO N ) (X4 3 - 1220 -0 0 )Th1s is a 5V power stabiltzer used for the cou nter unit . Ituses IC to prov 1de rated vo ltage with o ut making any adjust-me nts .MARK ER B OA RD (X52 - 00 0 5- 01)The MARKER board holds th e 100kHz cr ystal osci llator(0 1l and a 25 kH z multivibrator (02 and Q3 ) to producemarker stgnals at 25 kHz intervals to calibrate the TS-8 20 .0 4 amplifies the cal ibra tor signal.R ECT I FI ER BOARD ( X43 -1 090 - 02)This board holds all of the diode rectifiers lor the pow er sup-ply section of th e transcei ver. D 1 through 04 rectify thehtgh voltage. D5 rectifies the 300 vo lt supply . 06 rectif iesthe 210 volt supp l y. 07 recti fies the 90 volt supply. and D8through D 11 rectify the 13 .8 VDC supply.H V ( HI G H VOL T AGE) BOARD(X43 -111 0 - 00)This voltage divider c ~r cuit su pp li es a high vo ltage meteringsignal for the HV meter reading and also a low voltagescreen source used in the TU N mode of 'operation.INDI CATO R B OA R D (XS4 - 1180- 0 0)Th1s cercui t contro ls the l ight emitti ng diodes wh ich indicatew hen the RIT ci rcu it is on. wh en the fixed frequency oscilla-tOr is operattng. or when the VFO is oscillating.RELAY BOA R D (X43-1 1 90 -00IThts unit holds the s1and-by relay. a 5V power stabtlizer tofe ed power to the PL L circ uit. and smoothing capacitors toobta in low voltage DC power .The relay of thts umt tS used to select DC signal f or con -tro lling block b1as . cross chann el operation. etc32FI NA L BOARD IX56 -12.00 - 00)Thts unit 1ncludes all the circuits of the powe r amplifier ofthe ftnal stage wtth the exception of th e pi- network c ir cuit atth e output side.Fig . 22 FINA L B oard5.3 FINAL ST A GE POWER AMPLIFIERThis ampli f ier delivers 200 W PEP mp ut by 2 1ransmit powertubes (5200 1A). It is equi pped w ith a cooling fan to avoidtemperature nse during operat ion. ·. -- ·--- ·- --- - --~ --