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Icom IC-H12 Maintenance Manual

Manual is about: VHF RADIOTELEPHONE

Summary of IC-H12

  • Page 1

    Vhf radiotelephone ( 12 channels) l·c-h 2 maintenance manual.

  • Page 2

    Table of contents section specific, tions ........................................ 1 - section 2 operating controls.................................. 2 - 1 - 2 sectio 3 cl rcuit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 1 - 4 sectio sec 10 ec 10 1 0 3 -1 rec...

  • Page 3

    Section 1 spec i f i cati ons ge n e r a l number o f sem iconductors number of channels channel spacing frequency stability usable temperature antenna impedance power supply requirement current drain at 8.4v d imensions weight r e c e i v e r frequency range receiving system modulation acceptance i...

  • Page 4

    Sect i on 2 ope rat i ng controls top pan e l - 2 j tr a nsmit / batt e r y in dica to r 1 a n te n n a conn ector 6 ext e r n a l spea k e r jack 8 push-to- talk (ptt) f r ont pan e l - speake r 3 ch a n n el s elect switch 2 - 1 5 vo l um e con tr o l and power switch r e ar pan e l 9 charger conn...

  • Page 5

    J a n te nna co n n e ctor connect the su ppl ied flex i ble anten na. An external anten n a can be used, u si n g a bnc conn ector. @ t r ansmi t/batt e r y in d i cator i l lu m i nates in the transmit mode. Also in dicates the battery condit ion; du ring transmission. The voltage of n i ckel-cadm...

  • Page 6

    Sect ion 3 c i rcu i t desc r iption 3 - 1 rece i ve r c i rcui ts 3 - 1 - 1 antenna sw i tchi ng circuit signals from the antenna connector are fed to the antenna switching circuit through chebyshev low-pass filter consisting of l229, l230, c295, c297 and c298 in the p l l board. The antenna switch...

  • Page 7

    3 - 2 transmitte r circu its 3 - 2- 1 mic amp l i f i e r c i r cu i t audio signals from the microphone are fed to the limiter amplifier, consisting of 0125 0128, which has 6db/octave response between 300hz and 3khz. The output of the limiter amplifier is similar to rectangular waves and includes...

  • Page 8

    3 - 3 - 4 r e f e r en c e f r equency gen e r ator c i rcu i t reference frequency generator ic203 consists o f a crystal oscillator and a highspeed divider. X 201 oscil­ lates at 7.68 mhz, which is divided by 1024. The 7. 5khz reference frequency is fed to phase detector ic202. This 7.5khz referen...

  • Page 9

    • • • 3 - 4 - 2 l ed i n d i cato r c i r cuit is l e d is lit in the transmit mode, but when the power supply voltage becomes less than 5. 5v, it will ot be lit. E power supply voltage is divided by r148 and r149, and applied to the base of 0121. The emitter o 0121 is connected to the regulated 5v ...

  • Page 10

    "'" i ( ( ( 10.695mhz 455khz rf amp 1st mixer crystal 1st if amp ceramic noise squelch 0101 filter filter detector control 2sc2026 0103 0104, 0105 f1101 fl102 0113 0114, 0115 0102 2sk192 lom 1589 2sc2668 x 2 2sc2668 cfu455e2 2sa1048 2sc2458 x 2 indicator regulator t/r switch mixer 2nd noise squelch ...

  • Page 11

    Section 5 inside views main unit l102-l104 (rx band-pass f1101 (10.695mhz crystal pll unit j201 · j202 (matrix board connectors) ic201 (tc9122 programmable divider) (ba526 af power amp) (mc3357 if circuit ic) 107 (quadrature coil) (455khz ceramic filter) (10.240mhz 2nd lo crystal) (pa output trimmer...

  • Page 12

    • • secti on 6 mechanical pa r ts and disassembly 6 - 1 di sassembly of the cases 1. Turn the powe r switch off and rem ove the power pack. 2. Remove two screws a on the rear panel and four screws on the bottom as shown in the fig ure. 3. E o e t e front panel as shown i n the figure . At this t i m...

  • Page 13

    • - 6-2 d i sassembly of un i ts r ear pan e l 42289 ptt butto n m2 x 1 2 ::- round head screw x 2 42289 fr o n t p a n e l 30222 hen you wish to program some operation frequencies (channels ) , remove the rear panel, then u plug the connectors between the ma trix board and p l l board, and tilt the...

  • Page 14

    • • to see the printed sides of the pc boards, open the chassis by removing two screws © located above a n d below the ptt spring . :q d:= ---- 2 x 4-:: f l at ead screw ptt spri g 2x4- f l a ead sc e m ain unit (parts s i d e ) pll u n it (prin ted s i de ) contact co tact spr i n g 41 737 41 750...

  • Page 15

    6- 4 top panel construction © --- top panel top plate led 42062 slc-26ur (c-00830) n-56 42037 vr nut (a) 42061 panel 30282 =======.-- chassis a, b 30284 - washer r1 (vol) k 12181003e5n 1111-10ka r2 (sol) k1214014-5n1212 -10kb or k121b1003e5n1111 -10kb 2.5'1> nut ] 1 3.5'1> nut ====== -chassis a, b...

  • Page 16

    • - 6-5 un it bottom ass embly (bottom v iew) panel guide (a) @ act holder ©t> act spring rear panel (how to rep lace contact spring) 1. Remove the sli din g gu ide by removing the four screws as shown . 2. Re move the contact spring by removing the two screws as shown . 3. Set the new contact sprin...

  • Page 17

    Section 7 maintenance and adjustment 7 - 1 measuring instruments required for adjustment (1) frequency counter (2) signal generator (3) multimeter (4) ac ml llivol tmeter (5) rf voltmeter (6) rf wattmeter (terminated type) (7) af oscillator (8) oscilloscope (9) fm deviation meter (10) directional co...

  • Page 18

    7 - 2 preliminary checks 7 - 2 - 1 transmitte r output checks power supply 8.4v or battery ( ic-cm3) 1. Connect a 50 ohms rf wattmeter to the ant connector. 50s1 power m. 2. Setting the i c-h 12 to any programmed channel and key the transmitter. Observe the rf power output. 3. Power output should be...

  • Page 19

    3. Remove the transceiver case as shown on page 6 - 1 . Use a screw driver that fits the screw. 4. To open the hinge chassis remove the two screws as shown on page 6 - 2. 5. Attach an 8.0 - 1 1 .0v dc external power source to the battery clip or screw. Be sure to check the polarity. 6. In the case o...

  • Page 20

    7 - 4 - 4. P. L. L. 1. Check (a) with an oscilloscope. A lock failure is indicated by an instability or absence of the wave form. Check as follows: 2. Check the frequency of the master oscillator (7.68mhz). If a 7.5khz 5vp-p squarewave is not observed at (b), measure dc voltage on pin 5 of ic203 if ...

  • Page 21

    • • 7-5 bas ic alignment procedure 7. 5 - 1 p. L. L. Ci r cu i t a. Loe adjus ment 1. Connect the measuring instrument and set the control knobs as follows" • c onnec t an oscilloscope (l omhz band width) to r21 7. 2 . • c onn e c t oltmeter between r205 and ground. • s e he channel select switch at...

  • Page 22

    • • 2. Se the channel select switch at a programmed channel. • i n he recei e mode, adjust l211 for the programmed receiving frequency minus 10.695mhz. • in he ransmit mode, adjust l 212 for the programmed transmitting frequency. • s e he channel at a duplex channel, and adjust l213 for the desired ...

  • Page 23

    • • af millivolt- meter 3 . Od la ion check af oscillator power supply (8.4v) 0 dummy load directional coupler deviation meter a imum de i at i on . : with 1khz 12 0mv shall be 4. Skhz ±10%. Odula ion sensitivity: mic input voltage 12mv ± 3db at 1 khz. Deviation should be 3. 5khz. S ra io: connect h...

  • Page 24

    • • c. 2 d frequency check con ec a 10 . 24 hz ampl ifier to a frequency counter, check the frequency of x 101 (2nd osc) • 1 a l oo se couple. It should be: 10.240mhz ±400hz. Ec e i er spurious response connec a spea er and m i l li v o l t me te r to the ext sp terminal. Connect a 50 ohm dummy load...

  • Page 25

    • • 7 - 6 f requency prog ram m i ng the d i o d es or programming frequency have been already placed on the matrix boa r d of ic-h12 . Desired requency can be programmed by cutting certain diode(s) on the mat rix boa r d and the or l a or e requency programming is shown below; d i i d e d numbers i...

  • Page 26

    Table of frequencies and 'n' numbers to be utilized on the ic-h12 • f req. 'n' lo f req. Freq. ' n ' lo freq. 150. 815 188 147. 995 153.155 344 147.995 . 845 190 .185 346 .875 192 .215 3 48 . 905 194 .245 350 .935 196 . 275 352 . 965 198 .305 354 . 995 200 .335 356 5 . 0 25 202 .365 358 5 20 .395 36...

  • Page 27

    • fre q. ' n ' l o f req. F req. 'n' lo f req. 150.830 188 148. 010 . 530 368 " .860 190 . 560 37 0 " . 890 192 . 590 372 " . 920 194 . 620 374 " . 950 196 .650 376 " . 98 0 198 .680 37 8 " 151. 010 200 .710 38 0 " . 04 0 202 .740 382 " . 07 0 204 .77 0 384 " .100 206 .800 386 " .130 208 .830 388 " ...

  • Page 28

    • f req. 'n ' lo f req. 154. 515 434 148. 005 .665 444 .695 446 . 725 448 . 755 450 . 785 452 .815 454 . 8 45 456 . 875 458 . 905 460 .935 462 . 965 464 .995 466 155.025 468 . 0 55 470 . 085 472 15 474 5 476 . 75 478 .205 480 . 235 482 . 265 484 . 295 486 . 325 488 . 355 490 . 3 8 5 492 5 494 5 496 ...

  • Page 29

    Sect i on 9 vo ltage cha rts e t rans i sto rs vo ltage cha rt • measuring instrument is a 50kd./v multimeter. - • transmit :\it \'o. Ba. E collector emitte r 0 g ate or drain or source base or .\1ac\ q i o i 0 0 gnd 0.75 receive collector emitter remarks or or drain source 1 .2 gnd rf amp q l 0 0 0...

  • Page 30

    • • • • i c's vo ltage chart • measu ring i nstrument is a 5 0ks1/v multi meter. In t r ansm i t mo d e u i t i c o . R e m a r ks 1 2 3 4 5 6 7 a 9 1 0 1 1 1 2 1 3 1 4 1 5 m a i n 1 c o o m a i n i c 1 02 0 0 0 0 gnd 0 0 0 0 p l l i c 20 5 . 0 1 .0 0 0 4 . 4 0 0 4.4 0 , 0 0 0 i 0 gnd f = 1 56.Smhz ...

  • Page 31

    • • • secti on 10 t r ouble sh oot i ng no pow e r on t a r t o k u t a n n o t resoh·e i t . B a 1 t e r y i s d isc harged bad battery c o n tacts reverse polarity of batt eries ( ic-cm4 ). O k opened wire b e tween .:. T e r m i n al and power switch or defective po\ver s\.·vi t c h . Check q i 1...

  • Page 32

    • • lock f ailur e start y e s y e s che voltage of ic 01 ( p l l uni t ) . :>10. B u t cannot resolve it y e s refer t o " n o power o n ". Y e s defective x 2 0 i ( p l l unit). Defective x 202 (pll u n it ) . Defective i c 2 0 i ( p l l unit). 1 0 - 2 n o defective ic203 (p l l unit )..

  • Page 33

    • • n o r ec eptio n start check for opened wires or cold soldering between t c o n ­ n ec t or and m a i u n it. U t cannot resolve it. Replace the wires or resolder them. Loe k is failed. Refer to "lock failu r e ". Defective q 2 0 8 ( p l l unit ). Y e s defective x i 0 i ( m a in u n it) . 1 0 -...

  • Page 34

    • no transmit r f powe r s t a r t check for opened wires or cold soldering between ant con­ nector and main u nit. Y es chee k d 2 i 7 and ant connector. No replace the wires or resolder them. Lock is failed. Refer to " loc k failu re". No no no n o defective q 2 0 8 ( p l l unit). Defective q209 (...

  • Page 35

    • section 1 1 ic spec i fications tc-91 22p (bcd programmable counter) max™um rati n g s (ta = 2s0c) symbol description yoo supply voltage vin input voltage top r operating temperature tstr storage temperature pin connection block diagram 100 -sookn 0 1- z 5 n m n cl 0 0 u u u u ratings 1 0 ...

  • Page 36

    • mc-3357 ( low power fm i f ) maximum ra tings (ta = 2 5° c) symbol description vee supply voltage (max) vee operating supply voltage vin input voltage to p r operating temperature tstg storage temperature b lock d iagram vee 455 k h z f i lt e r pl' c o limiter input decoupling s 1 1 - 2 ratings 1...

  • Page 37

    .. • • tc- 5 0 8 1 ( phase comparato r ) maximum ratings (ta = 25°c) symbol desc ription vdd supply voltage vin input voltage topr operating tempe rature tstr storage tempe rature pin connection 2 3 4 5 6 7 8 z w c u c c z z o o 0 j: q. Q. Rat in g s 1 0 -0.3 - vdd +o.3 -30 - 7 5 -...

  • Page 38

    Sect i on 12 pa rts l i st [ef pa rts] [ ma i n un i t pa rts] r e f. Desc r i pt i on (part no) boa r d no. Locat i o n r e f . D e sc r i pt i o n (part n o ) boa r d no. Locat i o n d l l e d slc-26u r 0 124 transistor 2sc2458- g r 4 d 0 125 transistor 2sc2458- g r 4e r l variable k 1218 1003e5n ...

  • Page 39

    • [ m a in uni t pa r ts] [ m a in uni t pa r ts ] r e f . Desc r i p t i o n (pa rt no) boa r d no. Locat i o n r e f. D esc r i p t i on (part n o ) boa r d no. Location r 1 34 resistor 1 5kq - j e l r 1 0 3c c 1 1 4 ceramic 4p f / 50v 2b r 1 35 resistor l okq -j e l r 1 0 3c c 1 1 5 ceramic 0. 00...

  • Page 40

    • • [ m a i n un i t pa rts ] r e f. D e sc r i pt i o n (pa r t no) boa r d no. Locat i o n c174 e lectrolytic 1 oµf/16v rc2 4e c175 e lectrolytic 0.47µf/ 50v rc2 3e c 176 ceramic 470pf/ 50v 40 j 101 swi tch twn0301 1 0 b101 p. C. Board b-391c beads core d l -20p2. 6- 3-1. 2h [ p l l un it pa rts] ...

  • Page 41

    • [ pl l u n i t pa rts] [ pl l un i t pa rts ] r e f. Des c r i pt i o n ( p a r t no) boa r d no. Locat i on r e f . D e s c r i p t i o n (part no) boa r d no. Locat i o n r 244 r e s i s t or 470 - -j e l r l o 4g c253 ceramic 22p f/50v 1c r 245 resis or 270. -j e l r 10 4f c 254 ceramic 47p f /...

  • Page 42

    • [ m at r i x un i t p a r t s ) r e f . Descr i pti on (part no) boa r d no. Locat i o n 0401 transis or 2sa 1048-y 1 e 0402 transistor 2sc245 8-g r 1e r401 resis or 1ks! -j r10 1e r402 resis or 2.2ks! .J r10 1 e r403 resistor 10ks! .J r10 10 r404 res i sto r 100 n .J r10 3e r405 2. 2ks! .J r10 3b...

  • Page 43

    Main unit r6.0 t o r 2.0 c/29 cij() t o • , fi ic 101 iz ii ri., cl i .... T o q: r2.0 t o ciz& c121 :j s i r o tl. 8 rl/5 j; r117 j; q 116 q115 receiv. 3.3 5.F 3.9 3.3 3.3 3.F 0 0 0 0 0 0 transmit. 0 0 0 0 0 r/67 912'1 q.128 ro 111 t l.'1 :e cf63 v r 7.2 7.2 0 0 0 0 9 114 7.8 0 0 0.6 0.6 xi...

  • Page 44

    0104 rltj'! Ij. 112 b l23 r4.8 t . 1 lt1.2 t.5.8 r/51 6. 122 p l/05 r/47 6. 1 co r o t4. 0 ai: q. 103 r/05 9.1'1 8.4 r6.0 t o e. 121 8 10'1 9 - 3 c/08 q.102 q toi rs. 6 t o 9.101 9104 (}. /06 4.9 r4.2 14.6 loe iced ro.S r/24 t 0.1 fj. 120 q l/8 q l/ 7 a.4 r o i t4.8 tsv .Send lock d 0 { unlt1t:.K...

  • Page 45

    P l l u n i t lc 20 1 13 @ 500mv dup simp 8107 12oa 0.8 160,lls .,._ j s lji4.8v p·p foj> 2.2 e10 xr l ic203 \j cl x201 x2di 6.4 mhz 820'1 r23f 1'dns @ fin4.Bv d204 20 r4.8 to lf o t, s i"'i' 4.3 r o t,dup 4.1 t/.3 ro r24s r8.4 r223 c24" r22._ c247 r22!5 v t1.F r o tl.I.

  • Page 46

    V"l•cked locked llnlocleed 8v © 4.2 v ® locked 620 1 .2 0.8 9202 c.226 r21.3 @ /\_,l\ttoomv v ,,_,, l211 x 202 d210 /lf214 c231 &204 "' 0 fi.20 6 i ii ii ii ... Q.212 ro ra6 r(j t0.4 xz02 38. 8z75 hhz x203 7 . 5 0 12s hhz x204 36. 351 mhz q213 § 234 r o t4.8 9-4 glos '° r2/8 3.2 1.1 ill r219 f...

  • Page 47

    ., "' .. "' - bc -.30 + dc/3 .8v slc tst.Zr /.Zk z6v.F 180 /s/j .Ss bat f--- -- -1 c2 470.P m x -i 3 fi 3 0 ul "'o 'cj m x -i ijl 1l s-0 'h 0 470p 0 r ijl ij r 0 q - - - - -- - --, c/67 i nod r/71 /ok ct66 iz op lo rl.50 330 r/46 zz k rt44 " g c/j7 /0 3 3 k . .. on o, + c...

  • Page 48

    Seno 8a 7 tery di slc· z 6 ur ' r - - - - - - - - - - -- - - - - - - - - -- - - - -- - - - - - --- -- - - - - i . I pll i i i , i pl i vdd p , dz04 lz03 lbbb czz..S iop rz,4 z.Zk rz l'l z.Zk i czz6 ip g- .5 v c4 a rziz i,l rzl8 z20k. I r4l4 p40z jzoz rzoz , 3..3k qz03 l'rj o cz38 z. Z k k ' ...

  • Page 49

    Matrix unit ch 11 ch 10 ch 9 ch & ch 7 ch 6 i ch 5 ch 4 ch 3 ch 2 ch 1 a b n c c ·©••02 • c ·e[) 0401 • 0 i ' ' . .. Z z ' ' 8 - 3 .. N " z q ' ' ' ' ch11 h9 ch 7 ch 6 ch 4 ch 3 ch 1 d e.

  • Page 50

    P l l unit il w c (.) 8 - 2 .. .. 0 .., .. 0