Introduc tion T his Document written will help improve some of the shortcomings of the R anger R C I S S -158-E DX 12-10m band Multi-mode transc eiver, especially for use in UK and E U states where narrow fm is used more wildly. All mode 20dB R oofing F ilter to help resolve QR M\No ise F loor. F M A udio C lipper corrected waveform and helps impro ve audio punch on narrow F M mode F M receiver demodulator AF gain recovery increased for Narrow fm (based of E T S I\E N 9khz B\W 2.00khz deviation 100% max 60% dev= 1.2khz specs) Increased volume gain on lower fm narrow deviation levels at 60% level at 1.2K hz deviation suitable for Multi-Norm E uropean N arrow F M mode. LT 455G W -9.0K hz filter 455khz to widen F M bandwidth on receiver side. F m R eceiver audio quieting improved. G ain In\Out from E cho board equalised and improved. F requency stability Improved frequency drift and improved thermal prope rties to frequency critical parts. V C O whine Improved DC regulator and DC ripple capacitors. T w in F an extrac tors -added Hig h P ow er 25Watts F M mode added E xpanded upper frequenc y c ov erag e 30.105mhz-added Improv ed A lig nment of radio s uited for E U\UK market s \operation. T he following web links will provide handy referenc e guides to the radio. And credit goes to R ick of E uro R adios for his re-mastered drawings and schematic diagrams. P lease consider donating to this fab site to help s upport it. www.cbtricks.com
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INDE X S erv ic e Manual http://w w w .c btric ks .c om/radios /rc i/s s _ 158edx/g raphi c s /s s _ 158edx_ s m.pdfS c hematic s (Mos fet lates t) http://w w w .c btric ks .c om/radios /rc i/s s _ 158edx/g raphi c s /s s _ 158edx_ mos fet_ s c h.pd fP C B L ayout (Mos fet lates t) http://w w w .c btric ks .c om/radios /rc i/s s _ 158edx/g raphi c s /s s _ 158edx_ main_ pc b_ lay out_ top_ mos fet.pdf
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P arts to C hang es R emove parts and s ubs titute w ith new v alues as lis t ed. A ll modific ations have been v erified as g ood. th A L L R es is tors are 1/16 of a WA T T DC R eg ulation and R ipple C aps MG 941118 Amp 300W P NP R S 737-8868 1off Loc Q5-Up rated part BZ X 79 7V 5 Diode R S 544-3632 1off Loc D73-Up rated part 4700uF E lectro C ap R S 763-9431 1off Loc C 248-DC ripple 1000uF 25V DC E lectro R S 763-9428 1off Loc C 243-DC ripple 1000uF 25V DC E lectro R S 763-9428 1off Loc C 152-DC ripple S S B C arrier L eakag e reduc tion 220pF (221) 50V C apacitor Disc C eramic 1off Loc C 216-S S B C arrier Add P C B grounding links see pictures R oof F ilter 2K 7 R esistor R S 707-7704 1off Loc- LHS of 10M15 A filter 10.695Mhz 15khz Band W idth R oof F ilter 1off Loc I nsert C 62 place Quartz lab R oofing filter mount brass or tinned sheet 1mm Loc see picture 1A T one E nable-C 41 E nable tone to roll of high frequency audio for softer sound from radios speaker.
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Bridge S older jumper nearJ 4 topside of P C B F m T X /R x Narrow F M E T S I\E N s pec s LT 455G W 1off Loc-F L1-9.0khz bandwidth-T echno F ix UK 18K R esistor 1off Loc- R 59-F M R X De-mod G ain 47K R esistor 1off Loc- L 4 P in 1 and 3 Quieting 0R W ire Link R esistor 1off Loc- R 168-T X AF C lipper gain 1uF E lectro P olarised C apacitor 1 off Loc- C 148-T X AF Bass response less 1nF (102) C apacitor Disc C eramic 1 off Loc-C 155-T x HF roll off 10K R esistor 1off Loc- R 127 balance AF C lipper W aveform shape V C O T X F M Modulation Improv ements 100pF (101) C apacitor Disc C eramic 1off Loc-C 100 decoupling roll-off 220K R esistor 1off Loc- R 126-T X audio gain V C O 10K R esistor 1off Loc- R 124 AF G ain V C O 1M0 resistor 1off Loc- IC 3 P in 7/ground-stops V C O whine Armour W ax E bay 1off Loc V C O\Mixer P LL Offsets 10.950mhz Offsets Oscillator. 5khz +/- S hift c ontrol-Inc reas e rang e 100K R esistor 1off Loc- R 153 Increase 5khz shift
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E c ho B oard-Improv ed T X audio E qualis ed G ain in\out 10K R esistor 1off Loc- R 1 echo board 1K 2 R esistor 1off Loc-R 26 echo board 1nF (102) C apacitor Disc C eramic 1off Loc-C 4 echo board 100nF (104) C apacitor Disc C eramic 1off Loc- C 22, C 3 echo board Mis c
Heat-sink compound T -220 Heat sink and mounting kit R eplacement T ransistor Q51 ref
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2S C 2314 - F (2S C 2028/2S C 1957) E L E F L OW R F T R A NS IS T OR .
Modific ations - Out the box F ac tory F res h units Before commencing please check that radio function correctly and no apparent factory faults present. F unction switches work (band-move internal link to test) R F power OK R X sensitivity in all modes meets specs. C heck T X S S B that no carrier leakage. E nsure voice T ransmits and R X receives OK C heck all knobs and switches function and no shafts bent on knobs and channel selector\mode\band switch. T hes e tes t ens ure no fac tory faults before breaking s eals and any warranty! I would hig hly rec ommend tes ting eac h radio before hand to ens ure no problems or faults exis ts prior to modifying from bitter exp erienc e! E nable full band for testing purposes S ee videohttps://www.youtube.com/watch? v=V ye4meN9J Y 4R ef levels R F signal generator levels quoted in mic rovolts P d F M T X 4W atts Dev 2.00khz max with 1khz test tone 50 mV R MS (15khz LP F ) 26.955Mhz or 2.2khz dev iation if L T 455G W filter fitted. F M T X speech should not exceed 2.5khz Am T X 4W atts C arrier 90% Mod max with 1khz test tone 50mV R MS (15khz LP F ) 26.955Mhz S S B T X 20-22Watts max with 1khz test tone 50mV R MS (15khz LP F ) 26.955Mhz S peech will be around 10-15W atts C arrier F M Modulation 1.2khz=60% Distortion 5% or less (6K hz B\W idth filters E T S I\E N specs) Am 30% Modulation 1khz test tone distortion 5% or less S -9=50uV P d on 26.955Mhz
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DC R eg ulation and R ipple C aps R emove old parts and refit new values in place, mark capacitors with red nail polish to indicate fitted. P ress capacitors hard into P C B to prevent wobble. S emelab MG 9411 P NP T rans is tor, 18 A , 230 V , 3-P in T O-3P
R S 737-8868
L oc Q5-Up rated part
1off
R emove Q5 from P C B C lean heat sink compound from Q5 P rep transistor Q5 with new heat sink compound C heck ceramic pad is not cracked when reinserting Q 5 (If c rac ked, only replac e w ith c eramic type no othe r material types !!! ) F it new part MG 9411 to Q5 position and solder in. Add red nail polish to lock tight screw.
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B Z X 79 7V 5 Diode
R S 544-3632
4700uF 25V DC E lec tro C ap R S 763-9431
1off
1off
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L oc D73-8V reg ulation
L oc C 248-DC ripple
C 243-Up-rated P art 1000uF 25V E lectro P olarised C apacitor