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Icom IC-A24 Service Manual

Manual is about: VHF AIR BAND TRANSCEIVER

Summary of IC-A24

  • Page 1

    S-14115hz-c1-q july. 2007 vhf air band transcever ic-a24 ic-a24e ic-a6 ic-a6e.

  • Page 2

    This service manual describes the latest service information for the ic-a24/e and ic-a6/a6e vhf air band transceiver at the time of publication. Never connect the transceiver to an ac outlet or to a dc power supply that uses more than specified. This will ruin the transceiver. Do not expose the tran...

  • Page 3

    Table of contents section 1 specifications section 2 inside views section 4 circuit description 4 - 1 receiver circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 1 4 - 2 transmitter circuits . . . . . . . . . . . ...

  • Page 4: Section 1

    1 - 1 section 1 specifications ▄ general • frequency coverage : tx 118.000–136.975 mhz rx 108.000–136.975 mhz [ic-a24/e] 118.000–136.975 mhz [ic-a6/e] wx 161.650–163.275 mhz [usa] only • type of emission : 6k00a3e, 16k0g3e (weather channel; [usa] only) • channel spacing : 25 khz • number of memory c...

  • Page 5: Section 2

    2 - 1 section 2 inside views vor circuit (ic-a24 only) cpu (ic1: μpd78f0338gc-9eb) reset ic (ic2: bd5245g) eeprom (ic7: s-24cs64a01-t8t1-g) cpu5v regulator (ic3: xc6202p502pr) led drive q1: 2sb1132 q2: 2sc4211 +5v regulator (ic16: s-812c50bm-c5e-g) clock oscillator (x1: cr-747 9.8304 mhz) led drive ...

  • Page 6: Section 3

    3 - 1 section 3 disassembly instruction e e lo g ic/rf unit front panel a d b f j4 j4 c j i j lo g ic unit rf unit j h g rf unit l m l k be careful not to break and lost the sealing washer. • removing the chassis panel 1 remove the jack cap a. 2 remove [vol] knob b and [dial] knob c. 3 unscrew the a...

  • Page 7: Section 4

    4 - 1 section 4 circuit description ant ant lpf bpf bpf bpf bpf d8, d9 d13 sw rf amp amp q11 d14–d16 q12 1st mixer fl1 xtal q13 16 5 9 7 6 1 3 1st lf lc1 2nd mixer amp 2nd lf amp 2nd lf am fm anl ic1 am signal fm signal am/fm af sigunal to the af circuit ic2 fi2 q15 q16, q17 q18 d18 det det switch •...

  • Page 8

    4 - 2 r5 r5 am af signal to the am/fm switch (ic2, pin 6) fm af signal to the am/fm switch (ic2, pin7) ic2 ta31136f 1st if (30.05 mhz) from the if amplifier (q13) q18 c111 r92 r95 c108 q17 r97 r96 r94 c112 c109 d40 q16 am fm q15 r89 r86 r91 r87 c101 c104 c103 d41 fi2 2nd if filter 450 khz 3 mixer 2 ...

  • Page 9

    4 - 3 alc5v "vordet" signal from the am detector (q18) ic12 ic11 ic13 ic14 3 5 5 1 1 14 8 2 2 10 khz 30 khz bpf bpf bias buff. Limit. Fm det 7 7 7 3 phase shift lpf 3 6 comp. Comp. "vors" signal to the cpu (ic1, pin 2) "vorc" signal to the cpu (ic1, pin 3) "vord" signal to the cpu (ic1, pin 28) amp....

  • Page 10

    4 - 4 4-2 transmitter circuits 4-2-1 microphone amplifier circuit (rf unit) the microphone amplifier circuit amplifies audio signals with +6 db/octave pre-emphasis characteristics from the micro- phone to a level needed for the modulation circuit. Af signal from the internal/external microphone are ...

  • Page 11

    4 - 6 shift register prescaler phase detector loop filter programable counter programable divider x2 29.6 mhz “2nd lo” signal to the fm if ic 14 q59, d39, d45–d47 rx vco tx vco buffer buffer buffer q28 q29 q60 3 8 4 5 plst ic3 (tb31207) so sck to transmitter circuit to 1st mixer circuit d17 d6 9 q58...

  • Page 12

    1 - 2 4-5 port allocations 4-5-1 cpu (logic unit; ic1) pin number port name description 1 pcon outputs control signal for the 5 v regulator (ic16, q4, q6, q7, d10). 2 vors input port for the 30 hz phase signal. 3 vorc input port for the vor 30 hz standard signal. 4 bpcpi outputs the bias control sig...

  • Page 13: Section 5

    5 - 1 section 5 adjustment procedure 5-1 preparation most of adjustment must be adjusted in the "adjustment mode." cs-a24 cloning software (rev. 1.0 or later) and opc-478/u/uc cloning cable are required. ■ required test equipment equipment grade and range equipment grade and range dc power supply ou...

  • Page 14

    5 - 2 battery type detector battery type detector modulation analyzer distortion meter ac millivoltmeter dc power supply 11 v/5 a speaker (8 Ω) audio generator ac millivoltmeter to the antenna connector attenuator 20 db or 30 db rf power meter 0.1−10 w/50 Ω frequency counter ic-a24/e ic-a6/e [dc 11v...

  • Page 15

    5 - 3 5-2 adjustment adjustment adjustment condition operation idling current (for fi nal amp.) [ ] 1 • operating frequency: 127.500 mhz • connect a dc ammeter between the battery terminal and dc power supply (7.2 v). • measure the current at "00" point (a). • rotate [dial] to adjust the current a+5...

  • Page 16

    5 - 4 adjustment adjustment condition operation max. Modulation (preset) [ ] 4 • operating frequency: 127.500 mhz • connect an 11 v power supply to the [dc 11v] jack. • transmitting • rotate [dial] to set to 30% modulation. 5 • operating frequency: 118.025 mhz • transmitting 6 • operating frequency:...

  • Page 17

    5 - 5 software adjustment (continued) adjustment adjustment condition operation sensitivity [ ] 1 • operating frequency: 108.025 mhz • connect an ssg to the antenna connector and set as: level : –97 dbm* (3.2 µv) (no modulation) • receiving • push [ent] key. [ ] 2 • operating frequency: 127.500 mhz ...

  • Page 18

    5 - 6 software adjustment (continued) adjustment adjustment condition operation vor off (ic-a24 only) [ ] 1 • operating frequency: 108.000 mhz • connect a vor tester to the antenna connector and set as: level : –90 dbm* (7.1 µv) modulation : 9960 hz, 10% 30 hz, 30% bearing : 0° • receiving • push [e...

  • Page 19: Section 6

    6 - 1 section 6 parts list m.=mounted side (t: mounted on the top side, b: mounted on the bottom side) [logic unit] ref order description m. H/v no. No. Location ic1 1140012401 s.Ic upd780338gc-503-9eb-a b 45.1/18.7 ic2 1110006310 s.Ic bd5245g-tr b 53.8/4.4 ic3 1110006090 s.Ic xc6202p502pr b 76.2/6....

  • Page 20

    6 - 2 m.=mounted side (t: mounted on the top side, b: mounted on the bottom side) [logic unit] ref order description m. H/v no. No. Location c27 4030017460 s.Cer ecj0eb1e102k b 65/27.2 c28 4550006350 s.Tan teesvb2 1a 226m8r b 65.9/19.8 c29 4030016930 s.Cer ecj0eb1a104k b 68.7/21.1 c31 4030017460 s.C...

  • Page 21

    6 - 3 m.=mounted side (t: mounted on the top side, b: mounted on the bottom side) [rf unit] ref order description m. H/v no. No. Location ic1 1110003491 s.Ic ta31136fng (d,el) b 70.8/5.5 ic2 1130006221 s.Ic tc4w53fu (te12l,f) b 105.5/9.6 ic3 1130008831 s.Ic tb31207afng (el) b 93.3/20.2 ic5 113000757...

  • Page 22

    6 - 4 m.=mounted side (t: mounted on the top side, b: mounted on the bottom side) [rf unit] ref order description m. H/v no. No. Location r34 7030005210 s.Res erj2gej 822 x (8.2 k) t 61.3/14.3 r35 7030005050 s.Res erj2gej 103 x (10 k) t 59.9/9.4 r36 7030005570 s.Res erj2gej 820 x (82) t 63.8/12.8 r3...

  • Page 23

    6 - 5 m.=mounted side (t: mounted on the top side, b: mounted on the bottom side) [rf unit] ref order description m. H/v no. No. Location r341 7030010040 s.Res erj2gej-jpw b 88.3/21.4 r342 7030011140 s.Res erj8geyj 0r00v b 81.9/31.9 r343 7030011140 s.Res erj8geyj 0r00v b 81.5/21.9 r344 7030003860 s....

  • Page 24

    6 - 6 m.=mounted side (t: mounted on the top side, b: mounted on the bottom side) [rf unit] ref order description m. H/v no. No. Location c250 4550006250 s.Tan teesva 1a 106m8r b 47.5/36.8 c251 4030016930 s.Cer ecj0eb1a104k t 92.8/8.2 c253 4030016930 s.Cer ecj0eb1a104k t 94.3/3.4 c254 4030016930 s.C...

  • Page 25: Section 7

    Screw abbreviations a, b0, bt: self-tapping ph: pan head zk: black ni-zu: nickel-zinc sus: stainless 7 - 1 section 7 mechanical parts [chassis parts] ref order description qty. No. No. J1 6510022460 bnc-r162 1 sp1 2510001092 036d0801b 1 w1 8900009640 opc-963 1 mp1 8210020970 2791 front panel-1 (incl...

  • Page 26

    7 - 2 mp39 (c) mp27 (c) mp1 (l) ds1 (l) mp3 (l) mp2 (l) mp36 (c) s1 (l) r130 (l) mp4 (r) mp30 (c) mp36 (c) mp36 (c) mp36 (c) mp36 (c) mp36 (c) mp3 (r) mp36 (c) mp5 (r) mp36 (c) mp30 (c) mp6 (r) mp31 (c) mp7 (r) mp8 (r) mp2 (r) mc1 (l) ep2 (l) mp6 (c) mp32 (c) mp5 (c) mp1 (c) mp25 (c) mp26 (c) sp1 (c...

  • Page 27

    8 - 1 section 8 semiconductor information • transisters and fets • diodes a c a c a c a c a c a c a c a c a c a c a c a c a c a c a c a c 1ss400 1sv246 1sv271 hvc350b hvu131trf ma77 ma111 ma133 ma728 ma785 ma2s077 ma2s111 ma2s728 ma2s30400 l ma6s121 ma8051 m ma8082 m rb060l 40 sb07-03c (symbol: a) (...

  • Page 28: Section 9

    9 - 1 section 9 board layouts • logic unit (top view) pwr f clr anl 121.5 3 2 1 6 5 4 9 8 7 mr 0 ent sql ds2 ds3 ds5 ds6 ds7 ds8 ds9 ds10 mc1 h0 h5 h10 h15 h20 h25 h30 h35 h40 h45 h50 h55 h60 h65 h70 h75 h80 h85 h90 v0 v5 v10 v15 v20 v25 v30 v35 v40 v45.

  • Page 29: • Logic Unit (Bottom View)

    9 - 2 • logic unit (bottom view) 1 4 8 1 30 31 60 61 90 91 120 5 1 1 1 7 14 8 4 8 5 4 8 5 5 8 4 1 dial v ol gnd 20 21 1 40 to rf unit j6 j1 intmic mice lvin unlk gnd oe intmic extregc chgvh chgih chgc hv dcin beep pstb vcc vcc pck +5v rfstb pdata gnd gnd da2stb gnd deto ptt sbatt jackdet sdata sck c...

  • Page 30: • Rf Unit (Top View)

    9 - 3 • rf unit (top view) 1 4 8 5 14 8 1 7 mic ant chassis j1 ptt from battery pack chassis mp13 vccbt light sp dcin gnd 20 21 1 40 to logic unit j1 j6 lvin unlk gnd oe intmic extregc chgvh chgih chgc hv dcin beep pstb vcc vcc pck +5v rfstb pdata gnd gnd da2stb gnd deto ptt sbatt jackdet sdata sck ...

  • Page 31: • Rf Unit (Bottom View)

    9 - 4 • rf unit (bottom view) c9 c17 c20 c23 c28 c51 c52 c55 c56 c57 c58 c60 c61 c62 c63 c64 c65 c66 c67 c68 c69 c70 c72 c73 c74 c75 c76 c77 c78 c79 c80 c81 c82 c83 c84 c85 c91 c92 c93 c95 c96 c98 c99 c101 c102 c103 c104 c106 c107 c108 c109 c110 c111 c112 c113 c114 c115 c116 c117 c118 c119 c120 c128...

  • Page 32: Section 10

    10 - 1 section 10 block diagram chassis ant lpf pll ic mic mute matrix lcd eeprom driver ant sw pwr amp drive pre buff am pwr ctrl alc amp lpf buff buff fil loop fil ripple cr-791 x2 bpf rf amp bpf bpf xtal if amp if amp bpf ceramic fm det cdbc450cx24 x1 if amp if amp if amp am det agc amp agc amp a...

  • Page 33: Section 11

    11 - 1 section 11 voltage diagram *; refer to “parts list.” unr9213j q16 *ic12 6 5 7 0.001 c162 r36 15k 0. 1 c149 1k r139 0.001 c33 *r82 0.1 c146 0.001 c170 cr-747 x1 *d5 220p c159 100p c166 key s17 0.001 c142 0.001 c603 0.001 c173 0. 1 c29 sml-a12m t ds 3 r13 1.2k 100p c621 ma2s111 d1 0.47 c140 0.0...

  • Page 34

    11 - 2 *; refer to “parts list.” 0.001 c231 82n l67 q35 2sb1201 unr9210j q21 330k r296 1 c331 27k r306 m pz1608s221a ep15 1 c202 22p c362 0.001 c119 *c335 q29 2sc4403 r148 1k 39p c43 xp4315 q52 1 2 3 4 5 6 1 c356 18p c55 0.001 c361 0.001 c62 r103 27 0.0022 c257 82n l56 22k r248 10 c121 0.001 c29 0 ....

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    6f no.68, sec. 1 cheng-teh road, taipei, taiwan, r.O.C. Phone : +886 (02) 2559 1899 fax : +886 (02) 2559 1874 url : http://www.Asia-icom.Com e-mail : sales@asia-icom.Com zac de la plaine 1 rue brindejonc des moulinais bp 5804 31505 toulouse cedex, france phone : +33 (5) 61 36 03 03 fax : +33 (5) 61 ...

  • Page 36

    1-1-32, kamiminami, hirano-ku, osaka 547-0003, japan s-14115hz-c1-q © 2004–2007 icom inc..