Yaesu FT-902DM Instruction Manual Download Page 26 | Manualshive

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CARRIER UNIT (PB-1706A)

The carrier oscillator Q702

(2SK 19GR)

is followed

b y a buffer amplifier Q703

(2SC181 SY).

It oscil

lates  at  one  of the  following  frequencies,  depend
ing  on  the  mode  of  operation :  8 9 8 9   kHz  with
X 7 0 2 ;  8 9 8 6   kHz  with X70 1 ;  or 8 9 8 8 . 295 kHz with
X 703 .  The  crystal  selection  is  made  by  diode
switches D701  - D 703

( l S l S S S ) .

Diode D701 conducts to activate X 703 , which is

u sed for the CW , FSK, AM , and TUNE transmit

signal . Diode D702 conduc ts to activate X701 for

L S B and FSK reception. Diode D 703 conducts to

ac tivate X702 for USB and CW recep tion .

The carrier signal is fed to the ring demodulator
c onsisting o f D705 - D 708 (all

1S 1 007),

which

d emodulates the IF signal into audio using the
c arrier signal applied from Q703 . The audio is

then fed through relay contacts to the AF UNIT.

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CARR I E R UN I T .

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Summary of Contents for FT-902DM

Page 1: ...INSTRUCTION MANUAL FT 902DM YAESU MUSEN CO LTD TOKYO JAPAN ...

Page 2: ...TABLE CONTENTS Page GENERAL I SPECIFICATIONS 2 CONTROLS AND SWITCHES 5 REAR APRON CONNECTIONS 8 INSTALLATION II OPERATION I3 BLOCK DIAGRAM I9 CIRCUIT DESCRIPTION 20 MAINTENANCE AND ALIGNMENT 44 t ...

Page 3: ...er driver and final amplifier stages are solid state utili zing modern plug in printed circuit boards thus per mitting easy maintenance 1 The FT 902DM transceiver is entirely self con tained requiring only an antenna and power source for operation For base station operation AC power voltages of I00 l l 0 117 200 220 234 VAC may be chosen though the unit normally is sup plied with 117 volt capabili...

Page 4: ...4 H x 324 0 mm Weight 18 kg Emission LSB USB A3j CW A I AM A3h FM F3 option FT 902SD DE FSK F1 PA input power FT 902DM D DE SSB CW 180 watts DC AM FSK FM 80 watts DC FT 902SD SSB CW FSK FM 20 watts DC AM 5 watts DC Carrier suppression Better than 40 dB Un wanted sideband su ppression Better than 40 dB l 000 Hz Spurious radiation Better than 40 dB below rated output Transmitter frequ ency response ...

Page 5: ...ity at 20 kHz off 20 dB input at 14 MHz APF response Within 3 dB from 400 900 Hz Audio output Better than 3 watts 10 TH D Audio output impedance 4 16 Ohms FT 9020 SD DE DM MODEL DIFFERENCES o Built in feature X Available option FEATURE FT 9020 FT 902SD FT 902DE FT 902DM BAND CRYSTAL 160m 0 0 0 0 BAND CRYSTAL 80m 0 0 0 0 BAND CRYSTAL 40m 0 0 0 0 BAND CRYSTAL 30m 0 0 0 0 BAND CRYSTAL 2 0m 0 0 0 0 BA...

Page 6: ...icon Transisto r IC Schottky Barrier D iode 2SA496Y 2 MC3403P 1 Germanium Diode N0487C2 1 2SA564A R 2 MC1401 IBCP 2 1N60 12 2SA639 1 MC14042BCP 5 1S188FM 6 LED 2SA733 3 M C4044P 2 1S1007 30 G04 203SRO 12 2SA952L 13 µPC1008C 2SC372Y 4 TA7205AP 1 Sil icon D iode LED D isplay 2SC380TM Y 15 TA7063P 2 1S1555 101 HP5082 7623 6 2SC535A 1 TA7061AP 2 1SS53 7 2SC732TM 5 TA73lOP 1001 8 2SC735Y 3 TA7089M 1001...

Page 7: ...th for rejection of signal s above or below the desired signal 3 M The M bu t ton is pressed to store a fr e quency in the memory circuitry Whate v er frequency i s being read out on the digital d isplay will be the frequency stored when the M button is pushed be certain that you understand the function of every control before operating the transceiver The various front panel controls and switches...

Page 8: ... the fina l amplifier tubes caused b y excessive key down time during tune up 1 4 LOADING T his cont rol tu nes the outp ut circuit of th e pi net work to match the antenna feedline imp edance 1 5 PLATE This control tunes the plate circuit of the final amplifier 1 6 DTh1 This control allows dimming of the meter a nd dial lamp s 1 7 CARR KEYER The CARR and KEYER controls are mounted o n co n centri...

Page 9: ... LC position transmitter ALC volta g e m ay be read W hen the F T 902DM is in the receive mode the meter f tt nctions as an S m eter The NB MARK switch provides for actuation of either the Noise Blanker NB or cr y stal calibrator MARK The marker oscillator can produce cali bration signals a t intervals of either 25 kHz or I 00 k H z by proper posit i oning of a switch inside the ca b inet 22 POWER...

Page 10: ...r external VFO 9 FUSE F use holder requires 5 amp fus e for 117 volt or 3 amp fuse for 220 volt operation F or 1 2 volt DC operation a 20 amp fuse is installed in the pow e r cable W hen replacing fuses b e certain to install a fuse of the proper rating The warranty does not cover damage caused by improper fuse replacement 1 0 POWER Power receptacle Both AC and D C cable s are supplied 1 1 TONE Si...

Page 11: ... may be made through this ja c k The FT 902DM is set up for 1 70 Hz shift 18 IF OUT 1 Narrow bandwidth 8 9 MHz IF output i s avail able for use with an IF monitorscope e tc 19 REMOTE Provides switc h ed 1 3 5 VDC for relay control for external low pass filter units etc As the band switch is rotated I3 5 VD C wi ll appear at various pins on the R E MOTE jack Use a VOM to deter mine the proper pin f...

Page 12: ...OUTER CONDUCTOR ACC PIN 7 INNER CONDUCTOR PIN 8 OUTER CONDUCTOR EXTERNAL RECEIVER HF ANTENNA i lill l l F jHF ANT FTV 901R MUTE PLUG 430MHz ANTENNA EXT RCV II ia f 1111 11111111 11111111H l OOTPUT FHOiOM II 1111111111 11111111H NT a 11111111 llllllllHo 0 RF IN f D I T u ANT Ac c n d i LLE B CABLE A CABLE C 10 ...

Page 13: ...rating device such as a linear amplifier Avoid heat ducts and window locations which are ex posed to the hot sun a µ d you will keep your transceiver running at full speed for a long long time Be certain to ground the transceiver through a heavy braided cable less than 1 0 feet long Cold water pipes in newer houses probably are unsatis factory as grounding posts i t is much better practice to use ...

Page 14: ...on Tun ing Action ANTENNA CONSIDERATIONS The FT 902 transceivers are designed for operation using an antenna system presenting a 5 0 7 5 ohm resistive load at the antenna jack Amateur instal lations seldom meet this requirement over the entire spread of eve r y band but the final ampli fi er pi network is sufficiently forgiving to allow for minor deviations from t h e target figure However signi f...

Page 15: ...stening level and adjust the PRESELECT cont r a I for maximum receiver noise or signal level The PRESELECT control ma y require repeakin g a s t he main tuning dial is tuned across the band 3 The RX CLARIFIER may be utilize d if the received signal is drifting Pushing the RX button and rotat i ng the CLARIFIER control will provide a means of offsetting the receiver frequency 2 5 kHz without changi...

Page 16: ...ocket without this plug being so co n nected there will be no power applied to the tube h e aters Heater voltage is supplied through p i n s 1 and 2 of the accessory socket Note LOADING POSITIONS BAND POSITION 1 60 5 80 4 40 3 5 30 5 20 3 1 7 3 1 5 2 5 1 2 3 lOA 3 lOB 3 lOC 3 lOD 3 LOA D ING positions are nominal M inor variations from positions shown are to be expected Set the VOX GAIN control t ...

Page 17: ...om exceeding the 1 0 second limitation imposed by the timer thr o ugh use of t h e MO X position or the micro phone PTT switch SSB OPERATION After completion of the above tuning p rocedure set the MODE switch to USB or LSB as desired Set the V O X GA I N control to PTT and activate the transmitter by pushing the microphone PTT switch or the footswitch if used W hile speaking in a norma l voice int...

Page 18: ...may then be inserted into the KEY j ack R efer to the drawings on page 9 for details of the proper key line plug wiring The transmitter may be activated on CW by MO X PTT or by VO X semi break in as desired T he key up voltage across the key terminals is 7 volts while the key down current is 1 5 mA so most externa l electronic keyers may be used with the FT 902DM without modification The o p erato...

Page 19: ... and LSB For this reason no recalibration is required Once the calibration is properly aligned at the factory or in shop no further adj ustment is required for accurate frequency derivation The 25 kHz or 1 00 kHz calibrator is included largely for alignment purposes as it provides a useful reference signal for signal peaking etc Frequency readout on the FT 902DM digital display is straightforward ...

Page 20: ...by the use of some examples I You are operating on a net on 3 9 7 0 kHz and must QSY down 1 0 kHz to handle a piece of traffic With the VFO button depressed and the main dial on 3 970 kHz press M 3 970 is now memorized Move the main dial down to 3 960 kHz to handle the message When finished press MR for instant return to 3 970 kHz The main dial may be left at 3 960 kHz if further QSY to that frequ...

Page 21: ...5MHz 20m 22 9875 23t1875MHz J 7m 26 9875 27 4875MHz 1 Sm 29 9875 30 4675MHz 12 m 33A875 33 987SM i1 I OmA B 36 9875 37 9675MHz OmC O 37 9875 38 9875 MHz TRAN SMIT RECEIVE CON TROL BLOCK DIAGRA M I I I MARKER I I J _ _ _ _ RX I I L__ I I I I I I I NB I I I I I l MEMORY U N I T lJ 028 0 0 28 3 4 _J 15 9875MHz 17 987 1Hz 40m 2 1 48 MHz _L 30m 24 4875MHz c J 20m 2B 4875MHz T I 7m 32 4875MHz 1 Sm 35 48...

Page 22: ... rejection against cross modulation The amplified signal is then fed to the first mixer Q102 ND487C2 3R a Schottky barrier double balanced mixer for excellent intercept character istics The RF signal is mixed with a local signal delivered from the LOCAL UNIT resulting in a 8 9875 MHz first IF The IF signal is then ampli fied by 01 0 3 J3 1 0 and delivered to the FILTER UNIT The input and output of...

Page 23: ... 1 S I 5 5 5 to pin 5 of the IF UNIT 9 10 I I 12 18 I I I I 0305 2SKl9GR I PB 1995 0303 2SCl815GR I FI LTER UNJT L It 3 IF UNIT PB 1 704C The IF signal from pin 1 4 is fed to the gate of the IF first mixer Q4 0 3 SK5 1 03 where the IF signal is heterodyned with a 1 9 7475 M H z 6 f local signal d elivered from crystal oscillator 04 o s 2 SC 5 3 5 A and b u ffer am plifier 04 0 6 2 SC l 8 l 5 Y res...

Page 24: ...ate of RF amplfier Q 01 and to IF amplifiers Q403 and Q404 to control the gain of these stages for AGC purposes The time constant of the AGC voltage decay is selectable FAST SLOW by switch S2003 The AGC voltage is further amplified by Q408 2SK 1 9GR and Q407 2SA564A for signal strength indica tion on the front panel S meter D402 R413 R414 0403 15100 7 180 180 151007 AF AM 9V l 0 4 _ 0 _ 1 _ 3 _ S ...

Page 25: ...plified by Q908 2SC1 8 1 SY and fed to the AF UNIT at pin 6 0901 3SK51 I C901 0901 C902 RX I N 2 0001 151555 ClOOI t2V 3 ro_ R9QI N J 1 0 2 2K ir When no carrier is present in the 45 5 kHz IF the noise at the discriminator output is amplified by Q905 and Q906 both 2SC1 8 1 SY and detected by 0905 and 0 906 both 1 S 1 88FM to produce a DC voltage This voltage is applied to turn on Q907 2SC 1 8 1 SY...

Page 26: ... of D705 D708 all 1S 1 007 which d emodulates the IF signal into audio using the c arrier signal applied from Q703 The audio is then fed through relay contacts to the AF UNIT I CW AM FS K i TX J 8988 295kHz 18988 125kHz J g 0704 I I US81TX RX I CWIRX 8989kHz 0702 0703 g 3S K59Y I I LS81TX RX I FS K I I 8986kHz 2SKl9GR 2SCISISY 0 4 SSS OUT I R749 L701 D701 CW AM FSK 68 l mH 151007 TXl2V B J w IS US...

Page 27: ...audio output to the speaker The audio spectrum is shaped by an active low pass filter of fc 2 7 kHz 1 2 dB octave Operational amplifier Q5 04 MC3403 and AF amplifier Q5 05 2SC 732TM are placed into the audio circuit by the APF switch on the front panel The frequency of this selective amplifier is varied with the front panel APF control VR4 a b between 400 Hz and 900 Hz providing single signal nois...

Page 28: ...the drain voltage at pin 2 of the printed board will drop The drain of Q2 1 2 is directly connected to the base of Q303 2SC I 8 1 SY in the FILTER UNIT As the drain voltage of Q2 1 2 drops the base voltage of Q303 drops turning off Q303 The collector voltage will then increase producing a forward bias to D 3 0 1 1 S l 007 As D3 0 1 con ducts the signals will pass normally through the circuit When ...

Page 29: ... put signal is amplified by Q2 0 3 and fed to the RF UNIT The PROC LEVEL control VR5 b located on the front panel varies the resistance between the collector and emitter of Q2 07 2SC 181SY thus changing the input signal level to the filter The CW FSK AM and FM signals pass through Q2 0 1 2SK1 9GR and are fed to Q2 03 The ALC Automatic Level Control voltage detected at the grid circuit of the PA tu...

Page 30: ...g a 1 1 dot space weight AM PS 17z8A KEYERuNIT N 0 27 11 c w sv 1 08 D O T s r vv DASH 7t ___ _ ___ M _ j__j I I I I V R 5 VR 4 o I CD I K E Y SW 2 i 1 002 Q I 3 2SCl815Y S a 6 I L _ __ J Th e microph one signal is amplified by Q1 o s TA7063P and Q7 1 0 2SC 73 2TM and fed tq Q704 3SK59Y where it modulates the 8988 2 kHz carrier signal The output from T702 is fed to the NB U NIT in the same manner ...

Page 31: ...X UNIT The signal is ampli fied by 06 0 8 and Q 6 0 9 2 SC 1 8 1 SGR and fed t o the base of 06 1 0 2SCI 8 1 SGR When the signal is applied 06 1 0 conducts causing C6 2 1 to discharge The DC voltage of C 6 2 1 is then fed to the gate circuit of Q 6 0 4 MC 1 40 1 l B When pins I and 2 of Q604 are high the ou tput of the VOX gate of Q604 becomes low causing Q 6 0 6 2SC 1 8 1 SY to cut off thus turni...

Page 32: ...hey ex ceed the level set for maximum deviation of the transmitter frequency Q9 1 0 2SC 1 8 1 5Y acts as I I an active low pass filter to eliminate harmonics caused by the clipping VR902 determines the m aximum deviation The output from Q90 1 1s amplified by Q9 1 1 2SK34E and then fed to the modulator 0909 FC63 Q9 1 2 2SC 1 8 1 5Y oscillates at a crystal frequency of 8987 5 kHz and is frequency mo...

Page 33: ...ough diode switch D 1 3 0 1 D 1 3 12 all 1 S 1 555 to the PLL UNIT The frequency of each crystal is shown in Table I 3 1 VCO UNIT PB 2 1 66 The VCO Voltage Controlled Oscillator generates a heterodyne signal which is 8 9875 kHz higher than the operating frequency The frequency is locked by the voltage detected by the PLL UNIT Q 1 2 0 1 Q 1 2 1 0 all 2SK 1 9BL oscillate at the frequency given in Ta...

Page 34: ...ignal waveform is shaped prior to being supplied to a phase detector Q 1 0 7 MC4044P here the phase of the signal is com pared with the phase of the signal d elivered through wave shaper Q 1 1 0 6 buffer Q 1 1 0 5 2SC 1 8 1 5Y and amplifier Q 1 1 04 2SK1 9GR from the VFO UNIT Q 1 1 07 compares the phase of the two signals and converts the phase difference into the VCV voltage which controls the VC...

Page 35: ... 3 I LOCAL 0 r I PB 1 709A PLL UN I T No 1 1 I 002 TA73 1 0 P 003 2SC l815Y I I I I I I I I I I 16 1 2 1 8 10 C l 9 v c v 12 v HIX PL L HIX c_ _ __j l l l 91 1 LOCK 009 J I NDICATOR 2SCIBl5Y I 12 SQUELCH 33 ...

Page 36: ... o m i n al P r e m i x L o c a l F r eq u e n c y 1 60m 1 0 4875 10 9875 MH z L S B 10 486 1 0 986 MHz U S B 10 489 1 0 989 MH z 80 m 1 2 4875 12 9875 1 2 486 1 2 986 12 489 12 989 4om 1 5 9875 1 6 4875 1 5 986 16 486 I 15 989 1 6 489 C W A M 10 4883 1 2 9883 M H z 12 4883 12 9883 15 9883 16 4883 18 9883 1 9 4883 22 9883 23 4883 30m 1 8 9875 19 4875 1 8 986 1 9 86 1 8 989 19 489 2om I 22 9875 2 3...

Page 37: ...ough bu ffer am pli fie r 0 2 8 0 2 J F l 03 3 a n d Q 2 8 0 3 2SC785 to pulse sh aper 02 8 0 4 2SC785 1I LOI z H 0 2 0 JJPA 54 H I I I I I I I I I I I I I I I I I c I I L S I COUNTER U N I T P B 2 0 8 6 A NO 30 I _J L 35 The switching p u l se gen erated by Q2 8 0 4 is a l so fed t o 02 8 2 7 where the signal is divided to 1 5 000 t o 1 5 5 000 i n accordance wi th t h e pro gra m p reset by 02 8...

Page 38: ...educed power consumption The heaters of the two 6 1 468 are connected in series to operate at 1 2 Volts DC 1 Low voltage supply AC 1 1 5 Volt power delivered from the secondary winding of the transformer is rectified by D 1 0 0 1 and D 1 002 V06B in the RECTIFIER A UNIT PB 1 708 to provide the transistor supply voltage The rectified DC voltage is supplied through pin 8 and pin I of the AC plug to ...

Page 39: ... C 1 5 02 in PB 1 7 1 2A AC 1 90 Volts is rectified by D1 802 1 00 1 0 m RECTIFIER UNIT C to obtain 2 1 0 Volts for the screen grid supply of the power amplifier tubes The screen grid voltage is reduced to 1 80 volts for the FM AM and FSK modes The plate supply for the driver tube is obtained by rectifying 2 5 0 Volt AC by D 1 80 1 1 0 0 1 0 The DC voltage obtained from the RECTIFIER C UNIT is dro...

Page 40: ... 30 o _ S G I OC210V s9 R06 3W 15K 0 u N F S K A M FM SG 6 C Mr R0 8 1 2 B Y 7A SG 7 I 3W 3 3K o _ Q I I 002 009 u R09 A C l 90V 2 Q IO i0 O O 2W 470 110 6V RIO 4 7 I 9 18 13 5V I i i 17 BY I I 19 GNO I I IS 1t1 s I8 15 M sw I SSB FSK FM TXl2V I I 2S O A 04 639 005 006 1 1 2SCl815GR 2SCl815GR 1PB 1717 A RECT C U N I T No 1 8 I L _ _ _ _ _ _ _ _ _ _ _ _ _ _ J 38 ...

Page 41: ...r CW filter installation the jumper marked B must be removed r Referring to Figs 1 and 2 install the desired filter in the appropriate holes Make the fastening nuts snug CW filter only and solder the pins of the filter to the printed board Re install PB 1 9 915 in the chassis socket and re place the cover of the transceiver CW F I LTER AM F I LTER Figure 2 Loc k Washer S pri ngWasher N ut 39 Figur...

Page 42: ...is However in areas of very high occupancy where channels are crowded an additional FM crystal filter is an available option Refer to Fig 2 and remove the jumper wire shown Install the filter on the board solder the connections and install the FM Unit as described above The positions of the alignment potentiometers of in terest can be found by referring to Fig 2 Replace the circuit board cover and...

Page 43: ...the BLACK lead should be connected to the NEGATIVE terminal OUR WARRANTY DOES NOT COVER DAMAGE CAUSED BY REVERSED POLARITY CONNECTIONS Black Red I J C L 1 Jmm 2 I c i c i Fuse tt J 1 Black 4 Before connecting the DC power cable to the transceiver check the automobile voltage regulator level with the engine running bat tery charging The maximum charging rate should be 1 5 volts or less If the volta...

Page 44: ...ed Connect the 6 pin connector to the socket on the main chassis as shown Mount the KEYER UNIT as shown in Fig 2 and connect the cable t o the KEYER UNIT a s shown in the drawing The completed installation may be viewed in Fig 3 65 30060 IZG X6 Figure I P530063 IZ X4 P530063 IZ X 2 5T30080 1 Z X 2 U I 6 tl 1I I 6530060 IZG XS BOTTOM VIEW 42 I I Figure 3 Figu re 2 ...

Page 45: ...rter Unit FH 1 VFO Unit PB 1 440B 3330 Top View S e l e c t Switch Board M h F M Unit PB 1 7 1 8 Rec t B B o a rd P B 1 7 1 2 Capacitor Board P B 1 7 1 3 Bottom View 43 Unit D r i v e Board PB J 7 1 4 V1601 RF Unit PB 2 1 54 PLL Unit PB 1 709A VCO Unit PB 2 1 66 Tune Board PB 1 720B Tune Board PB 1 720 M J 1 2 VCO Unit T rimmer A Boa rd PB 1 723C Trimmer B Boa rd PB 1 724C Trimmer C Board PB 1 092...

Page 46: ...RED 1 RF Signal Generator Hewlett Packard Model 606A or equivalent with one volt output at S O Ohms and frequency coverage to 3 0 MHz 2 Vacuum Tube Voltmeter VTVM Hewlett Packard M odel 4 1 0B or equivalent with an RF probe good to 40 MHz 3 Dummy Load Yaesu model YP 1 5 0 o r equiv alent with 50 Ohm non reactive load imped ance rated to 1 50 watts average power 4 AF Signal Generator Hewlett Packar...

Page 47: ...t to either LSB or USB turn the VOX GAIN control to MOX and adjust the carrier balance controls VR7 0 1 and TC7 0 5 on PB 1 7 06A for a minimum meter reading with the METER switch in the PO position A more precise balance may be obtained by tuning a receiver which has an S meter to the transmitted frequency Adjust VR7 0 1 and TC7 0 5 for a mini mum S meter reading on the remote receiver while swit...

Page 48: ...nput level past the saturation point Adjust VR2 0 3 so as to obtain the same power output when the RF Processor switch is in the ON and OFF posi tions 9 IF PASSBAND TUNING ADJUSTMENT Tune the receiver to J 4 2 MHz in the USB mode and set the WIDTH control to the 1 2 o clock position Set the RF GAIN control fully clock wise Change the MODE switch from USB to LSB The receiver background noise at the...

Page 49: ...uni t Tune board PB 1 720 VR2101 Band swi tch 1 3 VOLTAGE REGULATOR ADJUSTMENT Connect a VTVM DC probe between pin 1 0 of MJ 1 PB 1 7 1 7A and ground Adjust 6V SET potentiome ter VR1 80 1 for exactly 6 Volts as indicated on the VTVM Rectifier C u n i t PB 1 7 1 A 1 4 BIAS ADJUSTMENT Q1so1 QJ804 Q1800 Q1803 Q1806 The final amplifier bias must be checked to ensure linearity and normal operating plat...

Page 50: ...ILE MAKING ADJUSTMENTS IN AREAS OF EXPOSED WI RING I Connect a dummy load to the antenna re ceptacle and set the METER switch to IC 2 Locate TC0 1 the neutralization variable capacitor shaft on the inside wall of the final amplifier compartment 3 Check the final amplifier idling current as described in part 14 of this section of the manual BIAS ADJUSTMENT 4 Tune up the transceiver at 29 MHz using ...

Page 51: ... indication Now set the VOX GAIN switch to MOX and adjust 1 1 Now you are ready to align the other bands Set the BAND switch to 1 5 set the main tuning dial for a reading of 2 1 000 MHz and set the PRESELECT control at 8 6 on its scale Dip the PLATE control for minimum IC indication while tuning Set the VOX GAIN control to MOX and adjust TC2 6o s and TC2 s o s for maximum PO indication on the mete...

Page 52: ... i l ter u n i t PB 1 995 Q 1 0 5 1 5 Because of possible interaction of adjust ments please repeat steps 1 3 and 1 4 1 6 Set the BAND switch t o 40 tune the m ain dial for a reading of 7 200 MHz and set the PRESELECT control to 6 5 on its scale Dip the PLATE control for a minimum IC reading while tuning Set the VOX GAIN control to MOX and adjust TC2 60 3 and TC2 s o 3 for maximum PO indication on...

Page 53: ... unit PB 1 7 1 1 Select Switch Board PB 7 18 c5 x r 0 F M unit PB 1 707 8 Qg 1 1 Qg10 Qgo9 Q91 Q913 Tgo3 Q914 J 3 0 0 3 Q1 103 T1101 Q 3 0 1 9 Q3 0 1 1 3 Cou nter unit P B 2086A 51 Memory u n it PB 1 787 P L L u n i t PB 1 709A ...

Page 54: ...YA E SU v 8103 A ...

Page 55: ......

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