Download ft.757gx ]i hf all mode computer aided transceiver
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FT.757GX ]I HF ALL MODE C O M P U T E RA I D E DT R A N S C E I V E R GENERAL DESCRIPTION The FT-7s7GXII combines the finest features of its famous predecessor, the FT_ ?57GX, with new developments in response to technological advances and to the m o s t p o p u l a r r e q u e s t sf r o m s e r ì o u s h f o p e r a t o r s . N e w a d v a n c e si n d j g j ! a l c o n t r o l a n d c o m p u t e r - a i d e dm a n u f a c t u r ì n gm e t h o d s a Ì l o w t h e F T - 7 5 7 G X I l t o o f f e r great versatility and operator convenience on all modes and all hf amateur radio bands, with 100 watts of PEP transmitter power oùtput on the amateur bands, and general coverage reception from 0.15 to 30 MHz. Special new digital features include operator selectablemode-dependent unìng steps, ten memory channels which store mode as well as fÎequency, auto-resume l o o p s c a n n i n gb e t w e e n d u a l V F O s ( o r a d j a c e n t m e m o r i e s ) , a s p e c i a l c l a r ì i i e r memory, and an improved CAT (Computer Aided Transceiver) System for simplified programming aùd more advanced control by an external computer. A 40dB IF Notch filter is provided along wiih continuously adjustabÌe lF Shift for minimizinginterferenceduring SSB, CW and ECSSreception of AM signals. wídeband AM and narrowband CW IF filters are included as standard. A switchable RF amplifier and 20dB attenuatorare provided to optimize sensitivity and d y n a m i c r a n g e o n a l l f r e q u e n c i e su n d e r a w i d e v a r i e t y o f c o n d j t i o n s , w h i l e t h e n o í s e b l a n k i n g p u l s e w i d t h c a n b e s e t o n t h e f r o n t p a n e l , c o n t i n u o u s l ya d j u s t able from narrow (ignition-type)to wide ("woodpecker") blankingpulse widths. Full break-in QSK CW operation is provided {'ith Yaesurs custorn designed electronic keyer built in, as a standard feature. l\ew high voltage solid state transmit/receive svritching circuitry is provided for direct t/r control of a wide variety of QSK and non-QSK linea. amplifìers. I AF speechprocessor' which SSB and AM signal punch can be increasedby the averagespeecll power c o m b i n e s c l i p p i n g a n d c o m p r e s s ì o nc i r c u i t r y t o o p t i m i z e úodulation assures clean \ir'ith minimurn distortion. Careful fillering before power' The diecast top half of output with a substantialincrease in average final power amplifier' and the FT-757GXll serves as the heatsink for the power FM and AFSK operation forced-air cooling through the chassis allows full when used with a heavy duty power supply' lB8 Desktop Scanning Optional accessories include your choice- of the lvlD the microprocessor Mìcrophone or the MH_188 Handy Scanning Microphone' and or FL-7000 500-watt controlled FC-75?AT 100-watt Automatic Antenna Tuner of whlch autornatically Automatic Solid State QSK Linear Amplifier, each the FAS-1 4R Remote s e l e c t s a n d t u n e s u p t o f i v e a n t e n n a sw h e n u s e d w i t h Antenna Selector' Series- ReguÌator Power supplies for the FT-757GXIÌ include the FP-757HD Heavy Duty control' or the Power Suppiy with forced-air cooling and automatic thermal fan as an exclter light-duty FP-700 standard supply, ìdeal when the transceiver ìs used power supplies AÌl for the FL-7000, or for low power and ]i8ht duty applications. can be wired îor l)o/ll1/117/200/220 or 231 vAC' F'l'-757GXll Dùct Flo$ Cooling S''rslem Fan fvloto. Shleld Plate Loca Unit 2 Chassls SPECIFICATIONS TRANSMITTER l60m band 80m band 40m band 30m band 20m band l?m band l5m band lzm band l0ú band Maximum FM deúanon 1 5k H z i.5 to 3.5 to 7.0 to 10.0to 14.0to 18.0to 21,0 to 24.5 ta 28.0 to RF Output inpedance {nominall 50 ohms, unbalanced 1.99999MHz 3.99999MHz 7.49999MHz MHz 10,49999 MHz 14,49999 MHz 18.49999 21.49999MHz 24,99999MHz 29.99999MHz Microphone impedarìce 500 to 600 ohms RECEIVER 150 kHz to 29.99999MHz (contjnuous) Tuning steps (selecrablel SSB & CW: 10 Hz or 1 kHzlstep AM: I kHz or 10 kHzlstep FM: 2.5 kHz or l0 kHz/step Circuìt type Triple-conversion superheterodyne Clarifier range unlimited (full receiver range) Emission types LSB, USB (J3E)i Cw (A1A); AM (AsE) 3NdFM (G3E) Sensitivity (for iodB S+N/N, exc FM) 1s0-250kHz250-s00kllz è09!9 sookllz SSB/CW l.0LrV 0.5uV 0.25uV .1uV AM lùrv 1uV (above FM: o.suv for 12dBSINAD 500kHz) SSB,CW & FM: 100WPEPIDC,witl sÌightly Lesson 10m band AM: 25W Carrier SSB Carrier suppression betÈr than 40dB below peak ourplrl Intemediate frequencies 47.060MH2, 8.2l5MHz,455kHz Unwanted sideband suppre.\sion (SSB) better than 50dB beÌow peak ourpul (l kHz tone) Image IF SpurÌous radiatioD better than 50dB beÌow peak ouLpur Audio 3rd rejection better lhan 70dB rejection beffèr rhàn 70dB {ali frequencies) Selectivity { 6/ 6odB) SSB, CW(W) & FSK CW(N) AM FM response L e s sr h a n - 6 d B f r o m 3 5 0 r o 2 g 0 0 H z distortion order intermodùlation better than -35d8 beÌow peak outplrt ( @ l . 1 M H z ,1 0 0 ! v ) 2.7/4.5 k{z 600 Hzl1.3 kHz 6/18 kHz 15/30 kHz Dynamicrange(CW(N)@l4MHz) better tha. 100d8 Reference oscillator stability betrer than 110ppm lrom 0 to ,10'C after l5 mìnute wa.mup MaxinuÌn audio power ourpur at least 1.5W inro 4 ohms w/10o/' TllD Audio output imp€dance ,1 to 16 ohms Modulation systems SSB/cw: active balanced moduìator AM: earÌy stage (low Ìevel) Fi\l: variable reacrance 3 GENERAL Options Supply voltage 13.5\DC !100/o Model MD IB8 MH-IBE FRB 757 MMB 20 Pover @nsumption Tramsitter (100W outpul) 2A l9A FIF 65A FIF-232C FP-757HD fP /00 FC 757AT FL 7000 FAS 1 ,1R Dimensions (wHD) 238 x 93 x 238mm {without Weight (approx) 5 . 2 k g ( 1 1 . 5l b ) SpecifÌcalions may be subject to change with out notice or oblì8ation. Part No. Desktop Scannlng Mic.oPhone D1000039 D1000040 Hand Scanning Microphone D3000280 Box Relay Control D6000032 l\'lobiìeMountlngBracket External Computer ln|erfaces for APPIe tI for RS 232C Heavy Duty Power SUPPIY r t a n d a _ dD r t Y P o E è - s u P D ì ) Automatic Antenna Tuner (100w) 500W QSK Automatic Linear Ampìifier Remote Anten.a Selector (l.2kw, lor use wìth FC 757AT or FL-7000) Base Statlon LoudsPeaker SP-767 Base Loudspeaker v/Phone Patch SP ?6?P Mobrle Lotdspèafe. SP-55 E-?5711(CAT-N) connecrion Cable (to FlF 232C) ACCÉSSORIES Supplied (w/o fuse) DC Power Cord (2 suppÌied) Fuses FT TsTGXrr (20A) FT-7s7SXIj (64) 3-pin Phone pluC (SH3603) RCA (phono) pÌugs(STP-58, 2 pcs) T9014900 Q0000009 Q0000012 P0090008 P0090018 F)F-232C FC-757 Ar FRONT PANEL CONTROLS L 7l q {r) PowER (4) lhis pushbutton switch turns the lransceive. o. and off. Frequency and rnode data stored in rhe memories and vfos is not affecred by thjs swirch, or by whether power is connecred ro since this dara is retalned the transceiver, by an internal lithium battery while the backup system is activated. MIC/DRIVE The inner MlCrophone control adjusts the gain o. rh. -ur'Tir .Jdio anp itie- r5-d du r 8 SSB and AM transmission {for FM, gain is preset internally). This control adjrists power output in SSB modes when the speech processor is off, and modulation level in the AM nodr. Ir is di hbt-d . en I F pro.ó.5of o and during FM and CW transmission. (2) MlCrophone This 8-pin co.nector accepts the plug of the MD-188 Desktop Mic or MH-188 Hand MÌc. Scanning controì lines from these microphones alloiv pushbutton fast and slow tuning from the microphone (dupljcatjng the functions of the tuning knob and FAST button). See page l7 for Th^ ort.r DRI\E ' olt o dú.rii. 'h" .arrie_ power outpùt level for CW, AM and FM rransmission. This control is disabled during SSB {5) AFIRF ói ér \olrme. (3) PHONES Monaural or stereo headphones with 4-t6 ohms impedance may be connected to this jack. Stereo headphones with a 3 conductor plug wÌll reproduce the audio in both ears, as with monauraÌ headphones with a 2-conductor plù9. Inserting a pÌug ìnto this jack dìsables the internaÌ or exlernaì loudspeaker. - 5 . o r r r o l d o t u ) 1. t h c S a j n o l r l c lhe or Fr h receiver RF and IF anrpliliers via rhe agc llne. This conlrol js normally set fully clockwise tor peak .eceive. sensjtivity. When it is set counterclockwise from maximum, the S meter rìinimum deflection point will be moved Lrp the scale, and weaker signals (or noisel 'the wìll be suppressed, although S-meler defÌecrion for stronger signals will remai. rhe same. This control also affects the squelch threshold, and so slould be set before the SQL (squelch) co.troÌ. outer noise blanker control adiusts the decay time of the noise bÌanker agc, whrch determìnes the wid.h of the bÌatking pulse when the nojse blanker is activated durÌng SSB and L \\ -p.èpr o 'a d \\4 q èr | .F 'o s Dllsps are stronger than the received carrier). (6) Tuning Knob and FAST butto. This knob tunes !he transcelver {9) BAND/CH (D\{N & uP keys) and H/C button DurÍng reception with a vfo, the two large D\\'l"l and LIP keys are used to change frequency bands, and for 500 kHz steps. The H/G (Ham/ GeneraÌ coverage band step selector) butto. determines rhether the DWN & UP keys step rhrough the amateur bands only, or in 500 kHz general coverage steps. A beep sou.ds when any of these a.e pfessed. See the Operation sec- at a fate m o d e a n d selecled t h e o p e r a t i . g b y determined by the FAST button: Tuning Rates Ín kllzlstep MODE SSB/CW AM FM FAST ON 1 kHz l0 kHz l0 kLIz FAST OFF 10 Hz 2.5 kllz tìon of lhis mànual for detalls. When receiving on a memory the H/G button is disabled and the DWN & UP keys step through the memories. Also, when the SCAN MODE swÌtch is pressed, the DwN & UP keys activate and oeJ ;\dr- pv\ .. d.nirg o-ruF-r ìèîoric.. This knob is disabled when the LOCK button Ìs pressed, durÌng transmÌssÌón or when operating on a memory. A torque adjusmenL screw for úe tuning knob is accessible through the hoÌe on the bottom of the transceiver, just benealh the knob (see page 16). (10) MODE Seìect Burton and Indicators Press rhis button to selecl the operating mode while receìvjng (a beep will sound). The selected mode js indicated by one ol the six LED (7) NOTCH/SHIFT The inner NOTCH controÌ actlvates lhe IF notch filre. when turned clockwise out of the click stop, and tunes the notch across the IF pass band. Its settjng is independen. of lhe operating freque.cy and IF Shift setting. Ser rhis conrrol inro rhe clÌck stop (olf) when the .orch fìlter is not needed. The norch fiìler is disabled in the l_M mode. (r1) S C A N M O D E P u s h b u n o nS w i t c h Press this 2 posillo. swirch to select sca.While depressed, the func ning facjlities. tions of Lhe DWN & UP keys and the VFO and Memory keys a.e altered (from the basic luncrjons described in this section) to select and control various scanning functions, as described in the Operarion section. The outer SHIFT conlrol seLs the position of the receiver IF !assband relatlve to the rece iving frequency in SSB, CW and AM modes, to suppress inrc.fe.ence o. neàrby chanrers. Al the l2 o!clock posìtion the IF passband is centered on the (dÌsplayed) receiving ireque. cy; tufn this control counlerclockwise lo 'o\^pr rhp lf p1 òo-.d. or .,o(au!.é ro ra:\r p a s sba.d. When no interference is prese.l, the set this conlroÌ to the l2 orclock position. (12) vFo and Memory Keys These six keys transfer frequency and mode rlrF v-o. a d TeTo I \. A bèép JarJ b-rq.p sounds when ore ls pressed. As they funcllon during transmil as well as .eceive, use care to avoid accidental changes whiìe rransmitt i n g . l w o k e y s h a v e ) , e L l o 1 vm a r k i n g s l o i n d r cate that data wlll be overwrirlcn when !hey àre pressed. some of rhese keys aiso take on special functìons when the SCA\ NIODE switch ls (8) SQL/NB (squeìch/Noise BÌanker) The inner squeÌch control is used to se! lhe rfrp.hod è\él or .r'on g srgn- nr roisa at rhich recciver audio is muled. lhis th.eshoÌd poi.t also serves as the scan stoP setting when scanni.g. Clockwise rotation Ìncreases the rhreshold level, causing the | ,o r..p . d ,o b '-l8ro I' d oisFo- c,pè. èa. Tl . \F é-p la,flLaI dar. VFO A/B This key exchangesrhc co.tents of the t{o vfos (calledA and Bl. 6 LOCK - auning knob locked SPLT - split frequency operation actlve CLAR clarifier active VFO A operatjng vfo, or vFOB - or - operation is on a memory MR The digital frequency display indicates the operating frequency with 100 Hz resolutÌon. When operating on a memory, the memory channel 'CH' Lo number (0 thru 9) is displayed wìth the rlght of the frequency. SPLIT Press this key to activate split frequency opera!ìon between the two vfos, and press il again ro cancel sPlir oPeration. MR/VFO ThÌs key switches operation beLween the last-used vfo and the last used memory. The frequency and mode data in the vfo and mem ory are unaffected. The disPlay indicales which (vfo or nenlory) is currently selected. (15) CLAR Press this butlon whlle recejving on a vio to actjvate cla.ifier operarion. The luning knob and D\4N & UP keys can lhen be used to lune the affecting the transmit frereceivef witho!t quency. Press this button again to cancel the change in receiver frequency and retur. to r,vhere you were. The clarifìer is dÌsabled when VFOZ|.l This key excharges the frequency and mode contents of the last used vfo and lhe last VFO>M P.ess this key when oPeratÌng on a vfo to srore the frequency and mode data from thal vfo into the lasl used memory. This wilÌ ov€rwrite previous memory data, and leave the vfo and memory lhe same. This key is ai.rbled $l.pr op^rd.inS on à îemor\ receiving on a memory. { 16) Pushbutton Svitches Each of these swilches has two positions; when depressed the ÌabelÌed function is on, and when undepressed rhe labeLled function is off, except for the NIETER swìtch descrjbed next. M>VFO Pressthis key when operaungon a memorvLo lransfer its dala into the lasl-used vfo. This will overwrite prevìous vfo data, leav irg r-è vlo dra nerru"y de '"np. A'èr Dresìng this key operation wiÌl be on the vfo. MhThR "e è. rs pr'hp ALC or potré- oL.prl functions of the meter during transmrssron. Power outpul lunctions (forward, or reverse) are in turn selecred by the FWD REV switcb on the rear panel. ALC is indicated whe. this switch ìs i. the depressed posÌtion, and power output when il ìs undepressed, (13) DLOCK This button disables the tuning knob to pre "LOCK" is vent accidental frequency changes. shown on the display when active. Press this buúon again to re enabìe tuninS. RF AMP activates the rf ampÌilier Ìn lhe recelver front end when depressed, tor màx imum receiver gain. ln the undepressed posi!lon the RF ampìifi€r is bl,!assed, for increased immunity to overload l.om strong signals on other frèquencies. (14) Meter & Dispray The neier shows relacive signal slrength Ìn Sunits on the uppermost scaLe wnen recelvÌn8' and either reLative power output (PO), trans_ or mitter automatic level control (ALC) ( s $ R ì pur du g .-dn ri"r e f r c ir è d p o w - . sion. The METER button on the lronr panel and rhe FwD REV switch on lhe rear pLìnel serect rhe meter functio. for rransmìssìon. ia l' -'.Fr!p A T T p d ' s a 2 0 d B" n c ' , ' u front end circult, to reduce sensitrvrry and avoid overload of the rf anplilier and mìxer when listening ro verl st.ong slgnals. To the right of lhe meter the ON AIR iidicator glows red when t.ansmìtting, a.d the cEN i.di_ caror glows Sreen when general coverage band stepping is selected {via lhe rllG bltton). PROC acrìvates the AF speech processo. to increase average speech power during SSB tfansmìssjon, according to the level set by the coNlP LE\JEL conrol on the rear panel. At the left side of the operating frequency, the display tube jncìudes the foÌlowing Ìnd:- NB/T actilates rhe noise blarker fbr SSB, CW and ,à\l reception. The NB control at the then be used ro set lower rìghr the blanki.g pulse wÌdth. 7 AGC-F activates fast agc decay time for SSB, (!r and AM rF.óprion. to fd' iliréLF \.rnn; g d r a r J r i n g o r l r s r e r i n Sr o \ c ' ) w é d h s i 8 naLs. When not depressed, slow agc decay is provided for more comfortable recep!ion ol strong s i8n als, The VOX switch activates voice-actuated $ansmit/receive switching, and serni break in CW keying. In SSB, AM & FM modes, when this the switch is in the depressed positio., transmìtter wilÌ be activated just by speaking into the micfophone. When finished speaking or releasing the CW key {Ìn CW node), the receiver wjll be automarically reactivated after a short delay, as set by the DELAY control on (17) MOX and VOX Pushbutton Swilches The transmjtter can be manually switched on and off by the MOX swirch. Tìris is useful for SWR measurement and antenna tuning. R E A R P A N E L C O N T R O L S& C O N N E C T O R S '.i: 'roì .!..'.41.c_, ií. 11.€', ..91 Ll i?-ì i9 ItktTE (3) LINEAR This pushbutton switch activates e{rernai controì of t/r sivirching by rhe FC-757AT, FL 7000 or other linear amplifier desìsned for QSK operation. If not using o.e of these accessories, this switch mùst be in rhe undepressed position for transmissìon. This srvitch atso functions togerher wìtì the MARKER swrLcn ro disable the memory backup, as described in rhe Operation section. DC 13.5V {r) This 4-pi. connector accepts l2 to 15V DC at l9 amperes (transmit), to power the transceiver. Pinout is shown on page 13. CAUTION: AC voltage or DC outside of this range may damage the transceiver. (2) BAND DATA This 8 pin molex connector provides parallel TTL-leve1 bandswitching signals (for rhe FC7574T Antenna Tunef), and also QsK conÍol signaLs for the FL 7000 Lìnear Amplifier. See the CAUTÌON .otice on page 14 ìl you wish to use another model linear anplifier. (4) DELAY This controÌ sers rhe delay between the time that speech stops or the CW key is opened and a the tirne that the receiver is reactivated when the VOX system is activated by lhe swÌtch on the front panel. (12) ANT Coaxial Jack This type-M (SO-239) jack is for the antenna system, antenna tuner or Ìinear amplÌfier input. impedance requiremenl is 50 ohms' un balanced. Use onìy a properLy matÌng type-M {PL 259) pìug and 50 or 52-ohm coaxial cable. (5) ANTI TRIP This controÌ sets the amount ol negalive receiver audio feedback applied to the VOX The level an1pLifier durìng VOX operarion. should be set so that speaker audio does nol key the transmitter, (I3) PATCH/AFSK This phono jack accepts transmitter input from a p h o n p p J r ' h o - A F \ K r o n p g e r e r d r o r .l m D è dance is 600 ohms, and the ìevel should be exrernalÌy adjusted to match rhat of the operatorrs micropho.e, producing the same power output wirh the same MIC gain control setting. (6) VOX GAIN This control sets the gain of the VOX anplifier for VOX operaLion. The optimum seLting depends on the microphone used and the voice characreristìcs of the operator. FWD-REV { I4) This switch selects meter indicatÌon of either forward or reverse relàtive rt power ourput during fansmission, when the METER swiLch on the fronl paneì ìs ìn the depressed (PO) positjon. Refer to the following description of the FWD SET control, and the description ol SwP nFa\u'èré r lé OpF-arior sp' io]. (7) COMP LEVEL This control sets the compression level of the é u c i o ! p è e . . o m p r è \ L o ra r r . g s S B r : ì m r ' sion wlth lhe processor (PROC switch) on See Lhe Operation section for adjustmena, (8) AM CAR This (recessed) trimmer potentiometer sets the ratio of transmìtted carrler to modulatio. ior AM rransmission. Adjuslmenl ls described in the OperaLion sectìon. (15) FWD SET Thìs potentìometer adjusts the sensitivity of the metef for forward and reverse PO funcrions during transmissìon. Adjust this conlrol for full scale meter deflection ìvhile tra.smltting a carrier wiah the FwD-REV swirch ser to rhe FWD position, so that SWR can be read on the meter in the REV positìon. (9) MARKER Set this pushbutton switch to the dePressed position to actìvate the 25kHz marker signal generator, which produces a carrier at n1ultl p . . , r 2 i t H / d ' . . r l è l - P q u p n . \' ì r g ^ o r the receìver. When the callbration signaì is not needed, this siritch should be olf (oul), -'. F! io ,. ovorc inr--fé.è ,.é { |lh nornlhls swirch aìso functions in conjuncron wrth the LINEAR switch to disabìe the memo.y backup as described later. { 16) EXT ALC This phono jack accepls transmìtter automatic level control volaage from a linear ampljfier Fr lor l'F l dr ri -' p \ i P . T h r " p p i - d \ o Ì - g P should be be.leen 0 and -5V DC, referenced to the outer contact (chassis ground). (I7) (10) cAT This 6 pin mini DIN jack provides access to rhe seriaÌ dara lines from rhe microcompuler a4a A D ' orvp, -_, fo_ .4nrrol of rhc lrJ-\ ceìver from an external computer. See the CAT sectio. of this maDual for details. AF OUT This phono jack provides consta.t ìow-level receiver audio, unaffected by rhe AF gaìn control, for tape recording, digitaÌ demodulators capable of hlgh impedance input or an external audio amplifier. Oùtput level is ap proxlmately 200mV peak ar 50 kllohms. (ll) PTT Jack This phono jack provides access to the PTT line, for external .eceive/t.ansmiL control by a lootswitch or other devlce. Connectlng the inner contact to the outer contact (chassjs (18) 'Ihis EXT SP (Erternal Speaker) 1/8-ìnch 2-conductor mìni phone jack provides ampÌifièd receiver output to drive an external 4- to 16-ohn Ìoudspeaker. ground) activares the transmitter. Maximurn open circLrit voltage present is 13.5V, and minimum cÌosed ci.cuit currenL is Lì.3 mA. ( l9) This ì 9 KEY inch 3-co.ductor phone jack accepts keyer paddles for rhe irternal electronic keyer, or a straighr CW key (when the Ìnternal keyer is switched off). Wjring connections are shown on page 17. Open circuit vollage is +sV DC a.d closed circuit current is 0.5 mA. {21} +8V This phono jack provides 8V DC at up to 100mA fof low power accessories. The center contact 122) +rs.sv CAUTION: None of the ùree KEY jack conracts are connecled to chassìsground. DO NOT connect the outer contact to chassis grourd- This phono jack provides 13.5V DC at up to 500 mA for poweri.g accessories. The cenrer contacl is positive. RF OLIT {20) This phono jack provides low ievel RF oulpul from an early stage of the transmitter, for e)!clung a rfansverrer. Note: Repairs to damage caused by exceeding lhe current capabiììties of the accessory DC jacks ("8V and +13.5V)may .or be covered by P o i v e r ì e v e Ì ì s a p p r o x j m a t e l y- 6 d B m ( 0 . 1 V r m s ) at 50 ohms. (23) the warranry policy. GND For best perfo.mance and safety, connecr this terminal to a good earth ground through the s h o r t e s t p a t h p o s s i bl e . T O P C O V E R ( K E Y I N G )C O N T R O L S 11. BREAK.IN {I) Thls slide switch seÌects semi i n C W o p e r a t i o n i n c o n j u n c t i o n wìth lhe l\'1()x and VOX swìtches on the front cated in .he folÌowing chart, BRTAK IN VOX MOX SEl/II OFF OFF SEMI OFF ON SE\fI ON OFF FULL FULL oFF I ON FULL oN I oFF '.2 rol {2) KEYER MAN/AUTO When this switch is set to Lhe AUTO position llp inèr1.' t bit - r.t prn(é.o I I. actìvated. Keyer manipulato. paddìes musr be connected to the KEY jack on the rear faÌrcl ro operate the keyer. Whe. a straìght key or bug ls used, set this srvitch io rhe XlANual posi ResuÌti.s functio. (3) SPEED 'Ihis slide poleftionerer sers the keying speed for rhe electronic ker-er when the KÈYER switch ls ser to AUTaJ and lhe keyer paddÌes are squeezed. Slìde this control to the right for faster kcying. Sidetone only (no L\) Tx wheÍ keydown (no rx) Seni break-in Cw Full break in CW Continuous carrler LÌ Semi break-in CW t0 INSTALLATION PRELIMINARY INSPECTION Upon opening the packing carton, inspect the transceiver carefùlly for any signs of danage. Check to ensure lhat all exposed controls and switches move freely, and that the cabinet has no dents or scratches. If you notice any damage, document it completely and contact the shipping company ìrnmediarely. Save dìe packing materials for possible futu.e use. BASE STATION INSTALLATION AC Power Supply The FT-757GXIÌ requires a power source of i2 to 15 volts DC, capable of up to 20 amperes on voice peaks. For base station insrallations, Yaesu offers a variety of AC power sÌrpplies, alÌ of which rnay be used vith AC line voltages of 100, 110, 117, 200, 220 or 234 VAC. Ho$,ever, before connectiDg any power supply to the transceiver or AC line, make certain that the supply is properly ser up for the local ljne voltage, and that the correct fuse in instaued. The FP-757HD is a heavy duty series regulator power supply capable of 50% duty cycle operation with full po\r'er transmissions for up to 30 minutes at a tim€. Forced-ai. eooling is provided over an extra large internal heatsink. The FP-757HD requires a 6-amp fuse for 1 0 0 , 1 1 0 o r 1 1 7V A C , o r a 3 - a m p f u s e f o ! 2 0 0 , P o t r è r l r a n q f o r m e rp r i m a r J 220 or 234 VA.. c o n n e c t i o n sf o r l h e d i f f e r e n t l i n e v o l t a g e s are shor/n on the next pa8e. The FP-700 pover supply may be used for light duty operation with the FT-757GXII (CW, SSB or reduced-power FM and AM). AC voltages, fuse reqìiirements and power transformer wiring are the same as for the FP 757HD as described above and shown in the diagram on the nexr page, but the plastic sleeve on rhe supply DC cable must be cut to allo\r connecrion ro rhe speaker in the power supply. NE\ER CONNECTAC POWER,OR DC 15V,DIRECTLY TO THE FT 75?GXIt. Make certain that the POWER switch on the front panel of the FT-757GXÌI is OFF {out) before connecling power to the tra.sceiver, aDd doúbte check to make sure that the polarity of the connections is correcr before swilchjng the transcelver on, f t - I l l FP.757HD ffi rr tl-tf F P . 7 5 7 H DP O W E RT R A N S F O R M E RP N t [ 4 A B YC O N N E C T I O N S Equipment Location and GroÙnding lf all base slation inslalLations, the GND I ol rhP r' 'n 'è \F_ un te rin should be connectedbv a heavy braided cabÌe to a good earth ground. Best perlornànce oo all frequencles mav requÌre that the groundlng cable be less ùan 10 leer (3 meters) long' All station squipment shouid have ils own grounding cable (jndepe.denr of signal or controÌ cables), connected !o à conmon point on the grounding bus, close Lo thc trans'eìver or lÌnear anrpÌifier {if used). See the dragram The FT-7;7GXII is designed for use wrth anv antenna sysrem having a 50-ohm resistve rmpeArirÒmarlc dance a! the operatjng frequencv included i s ( A F P ) c i r c u i t f y finaÌ protecrion f i n a l tra's p r o t e c t t h c in !he transmitter to p o w e r outpur istors by automaticallv reduci'g when a. jmPedance misnatch (high SWR) is present. \lith a. SNR ot 3:l Ior exarìple, onLl a b o u t ? 5 0 / oo f f u l l p o s e r o u t p u r i s a v à i l a b l e . Despile this prolection, the FT-757GXll should never be swÌtched to transmit when no anrenna jack' or dummy load is connecred to the ANT plug to Use so-ohm coaxiaL cabLe with a proper o r a n r e n n a t o t h e connecl !he lransceiver p e ' m i L t h e load, and if SWR is too high lo desired performa.cc, connect an anlenna tuner such as the automatic FC-757AT or the FC 700 betveen the transceiver a.d rhe anrennlì See page 22 for SWR measurement wllh the FT 757GXll, dnd pages11-16 for inter'Ónnection Locare the transcerver so that air can flow freeiy over the heatsink a.d u.def and behind !he case. Avold PÌacing anylhing on top of Lhe transcejver, and do not pÌace !he traùscelver on top of anorher heat generatìng devìce such as a linear amPlilier. 12 (3) MOBILE INSTALLATIOT{ (Negatìve Ground vehicles oniy) Make sure the POWER srvitch on the transceiver is OFF, and connect rhe DC cable TLP The DC power cable for mobile instaÌlarion is .uppÌiFd $ L I F rransrptrer, Pìéaqpr,!irù the NOTICE on page 11befo.e making power con nections. The DC cable should be connected directly to the vehicle battery, rather than to the Ìgnition or accessory circuitry. Route the cable as far away from ignition cables as possible, and then cut off any exrra cable in order to minimìze voltage drop losses ni .o..,F be os shows the plug pjn connections. The positive RED wire must includ€ a 20 amp luse, instaìled in rhe supplied qable. Always check to ensure that dìis srrirch is OFF beiore startirg the engire. FUSE Ratings: 20A for FT 757GXÌ1, 6A.or fT-7575\I Mobile Antenna Installation Please review the base station anrenna information on the previous page. An antenna tuner such as the FC 757AT is particularìy desirable i. a mobile statlon, where the shorr antenna elements have very narrow bandwidth. Make sure rhat the shield of rhe snrenna coax is fi.mÌy grounded to the car body ar rhe antenna feedpoint. ( r ) Do nor .onnecr the L.ble ro t'e tra r5ce:\'r unr,r drrcr thF p_oDer conne. iors are made to the battery; the RED cable lead to the POSITIVE battery termjnal, and BLACK lead to the NEGATIVE terminal. Make sure the battery terminal connecLions are light, and remember !o check r L r F 1 ]p e r i o d . . d l ) f o r " . 9 n " o l o o . - r i r g \ 2 ) \ 4 è , s u- rlè .olrdgè Ji ,os. he bJr,èr) termìnals with the e.gine running fast e.ough to show a charge. ll above l5 volts, the aulomobile voìlage regulator r u" bF "Jjus,Fd ru --Jr , p ha .ha-ging voltage belore proceedìng, Mounting The optional MMB 20 Mobiìe Mounring Bracker for the FT-757GXlI aÌìows quick insertion and removal of the transceiver from rhe vehicle. Complete instructions are provided wjth the b.acket, which lr1ay be installed eitter aDove o. underneath the rransceiver (see phoro). FUSE : 64 (FT-757SXIl ) 2 0 a( F f 7 5 7 G X I l ) BLACK BATfERY TER]\4INALS . F-r r:r '-Fì-t--.-----------_\\ ''__-_--e' J /;::::::r- a BLAcr QED l\ -] - //-!! - u FUSE HOLDER DC Power Cable Connections lvlÀ48-20Mobile À,lountlngB.acker t3 \ \:r- ) TLRI/INALS INTERCONNECT IONS Linear Amplifiers The FT-757GXII includes a high voltage (1s0V) .apable of handlirB Lp lo rrdas:sror ,$ir.t 1.5 amperes DC, to control transmit/receive switching of a linear ampiifier via pin 6 of the BAND DATA jack. However, make ceràrn that the t/r switching requirements of your linear amplifier do not exceed these limÌls, and that the lìnear switching voltage is +DC, and not DC or AC. Yaesu offers the oplional FRB-757 Relay Box for l/r switching of linears that require negative or AC switching, or higher voltage or current srvitchÌng. The FRB-757 installs between the relay jack on !he amplÌfier and the PTT jack on the transceìver, ancl rs capable of switching uP to 250V AC or DC, at up to 2.54. If using the FC-757AT antenna tuner or a QSK linear amplifier such as the Yaesu FL-?000 or Alpha 78 connect pin 8 (INH, transmjrter inhi bit) of the BAND DATA jack to the exciter control llne from the linear, and set the LINEAR switch to the ON (depressed) position . r.urrrv dnsnire|- a.t.raIor ro a t4$ rhe in the Linear Lo control the transceiver. If using a non-QSK linear amplifier s'ch as the Yaesu FL-21008, or most Henry or Heathkit linears, make sure thal the LINEAR switch on che rransceiver is oFF (outl. T 1l F f-757GXrl SX ll + FP-/5IHD :m. r FT?57GXN,/SXN f,! f|flfl F T - I 5 7 G XI I / S X N + F T V . 7 O O +F P . 7 5 7 I ] D F*;_l L =:Ì] FL-7000 V FT 757GX]I+ FL TO(](] LINÉAR i8 T È: I QSK LINEAR FP.757ND Ff 751GXn t -.,- -t,- r- i--, 9 E ! Í 9 f,É I E 1 -- g:: B e l a vc o n t r o l v ó l r a gi ieo m r h e l n e a r a m p l i l i èmr ù s rb e l e $ r h a n5 0 V , ó n d r e l a yc o i c u t r e n l e $ t h a o3 0 0 m , A . P L N I ,a M l @ @ I I . r . " , . T , \ î : , ' . ,_ _ _ _ _ l FRB-757 CIRCUIT DIAGRAM t5 IEF {EF fltt-- {f,F rc 757AT FI 757GXNSXN FT-757GXII ,iSX]i + FAS I 4R + FC.75IAT Torque Adjustme.t BOTTOM l6 Sdew rvltcRoPHoNEs fvlH-f Bs MD. EA PLUG CONNECTIONS :r''''''É 'DF= . hI N0 ù*L *-,,,@,+ C..-..-O ), -t v - -llnn , f----_-.------{4 , Center Conducto. --llll1Ì:à-È ._-- [ 4 o . a u r a H e a d p h o n eP l ! g .-'rffiiÉn! L ' I T Externa keyer P ug ::rrlneq-,rt qrì%.p a--.-ì a___o Ste.eo HeadphóneP ug ar cND 12)s. ou_f it s. rN (4-ìPÌr AGc l5_iì oNC c a T ( M n D N )P u g 17 OPERATION Press the MODE button (repeatedly, if necessary) lo selecr the desÌred mode of emission. Before plugging lhe power supply inro the walì outlet (in base installation), ensure rhat !he power supply is wired for your AC line voltage. Make certain thar rhe proper fuse 1s instaìled, and that ir is p.ope.Ìy connecred to the transceiver as described in the lnstal lation sectio.. Also nake sure the antenna a.d ground are connected. Refef to Lhe Memory Backup informatìor below to enabie the backup. Turn dre AF gajn conrrol clockwise for comfortabÌe receiver voÌume. lf you do not have a scanning microphone, qse the FAST buLton on ."F r or Pdl.l J.\ó .J ing cr.po (with the tuning knob), and then set the FASI' Notice that both coarse and fìne tuning sreps are mode dependent, as shown on page 6. Connect a microphone, if desired, ro the trllC jack. See page 17 for microphone informatìon. For CW operation, co.necr ke)ref paddles or a Cw key as shown on page 17 to the KEY jack on \4H-l88 dn r,g n If ,or ".. è- \'D-l88 rophone rhe scan keys on the mìcrophonecan greatly faciìitate vfo tuning wìth rhe tuning knob: operate .he tuning knob wilh one ha.d "ì e l-Fp g.ou o h"rd orrhè n.rophone, FAST bLrtbn. This alLows qulck searching ", fAqT b|.t.on fo d. r\ r-\ l " r'l 1 - ed and then easl fine tuning when the FAST button js reÌeased. To juÌnp up or dowi one coarse slep, press the mìcrophone FAST and either UP or DO\\N kcy logether. Preser the POIVER swirch off, and all push buttons to lhe undepressed posìtìo.. Set dre other controls as folÌows: MIC flrlly counterclockwise DRIVE - fuÌly cou.rerclockwise AF - fulìy countercìockwise RF - fuily clockwise NOTCH - fully counterclockwise (lnto rhe OFF cÌicksrop) SHIFT - l2 orclock positìon NB 12 orclock posjtìon. Initial Poq,er NOTE: U.der certain condjtìons the tunlDg knob ìs deac.ivated. These are rhen the D LOCK (dial lock), \,1R (memory recall) o. SCAN À,IODE functio.s are active. When rhe dial is locked or a memory has been recaiÌed, iLOCKT and rMR' appear, respecrively, on the dlsplay, Press the D LOCK buftor to deactivate Lhe dìal lock, or press the MR/VFO button to return control lo a vfo. If nelther of the above-lnentioned conditions is dispìayed reset the SCAN lvlODE button lo the u.depressed position to turn off Up and Tuning | rè . d r,c \lO\ ord VO\ bJflo 5 .ró I I the u.depressed (out) positions, and then switch on the power suppiy, followed by the fansceiver POWER swltch. lhe neter and dìs play should Ìight, vith the display ìndicating the default (memory clear) state: VFO A and 7.000.0. Also, the green GEN and yelÌow LSB indicarors shouìd ljght (also defaults). V!. - Memory Backup Betore leaving the factory the memory backùp systen1 is turned olf. Actjvate the backrip by settìng the N{ARKIR and LINEAR swìrches on the rear panel to rheìr undepresscd (off) posi !ions. lf you are usi.g a QSK linear rhe LINEAR slvitch Íìust be kept ìn the depressed position, in vhich case onÌI the IUARKER svirch reeds to be set ro off. Press rhe H/G key and observe the steps of lhe DwN and UP keys (the GEN indicator js olf lof amateur ba.d steps)r and then press D\1N and UP keys to select the operatìng band (for which rhe antenna is resonanr). The Ham/Gen (H/G) selection affects only the stepping action of the DWN and UP keys when tu.ìng a vlo. You c:i. use either selection lo receive on any frequency, or to transmit in !hc amareur bands. The transmitter is dlsabled oulside of the 500 kHz amareur band segments regardless of Ham/Gen selection. If you want to cÌear aìl nrenories, of if you plan to srore the trrìnsceivef lor a long time vithout po\!er con.ecred, dìsable rhe backup system bv pressing borh the LINEAR and MARKER swirches (to O\) rvlriie rhe transceiver is off. t8 SSB Reception, Interference rarely be needed below l0 MHz, unless you have a sll]all antenna or your sration is ìn a quiet environmen!. Do not activate the attenuator and RF Ai\{P at rhe same timet instead, swìtch Reduction Excepr for the vfo and memory conlrol keys, ' l a r e m d r n .g . u | l o \é rè éitP fo provjded to reduce or eli|ninate Lhe v:tnous types of noise, inrerference and distortlon thar can obslruct comfortable receplion, Oper ation is fjrst described for SSB (USB or LSB) 'l he setti.gs described up to this point a.e besL lor tLrning and receiving weak signals under most conditlons, In most cases, once you have runed in a starion, you eill vant Lo set the AGC F off (out, slow agc) for most comforiable listenlng. If you are working a strong sration (consistently above S-9), tur. on the rhe atrenuator if ir isn't already on, or turn off the RF AlvlP (if jt's on), and decrease rhe Rl_ gaìf so thar his sigùal just moves the S meter above its (raised) restìng posìtion. You should.orice a reduclion in backgroundnoise and more comfrìftable copy. reception o. an amateur band, with varìalìons for orher modes descfibed later. Press the MODE button to select USB and tune ro the 14, 21 or 28 À4Hz phone band (if your antenna is for a band below 10 MHz, select rhat band and rhe LSB mode). Aiso, set the AGC F butto. for fast agc actìon (depressed). Rl_ AMP & Attenuator Careful adjusment ol !he receiver front end is necessaryfor optìmumreception, and shouÌd be treated as first prioriLy al the starl of a n o p e r a t i n g s e s s i o n , o r e h e n c h a n g ì n 8m o d e s , bands o. afte.nas. To ser up rhe receiver for optimun sensitivityi first make sure the RF gain conLrol ìs fuLly clockwise, and the rf ampÌifier and att€nualor àre off (RF AMP and Whe. .etu.ing the vfo, set the AGC-F back on (last), and return the RF and ATT ro rheir prevìous settings (ìf you are liste.ing for iF Shift & Notch Fllter ATT undepfessed). lrom stàtions lf you expcrience interlefe.ce , urb/ f.aqua ìè "frFr rur.ng i| à o' On a cleaf frequency, check for any S meter reading on the backgroundnojse Ìevel (hiss or crackÌe). if the S-meter deflects above 3, turn on the attenùaror(press ATT). Otherwise, if the background noise gives no defÌection, rurn on the RF AMP and agai. norc the S_meter reading or backgIou.d roìse: if it is above 3 S-units, turn the RF AMP back off (leaving it on r!ould :ncrease the S meler readings ol received slgnals, but vould .ot improve the ' , a r o I d , d - r . , , c L - , i i - o l r q u \ l described, .otare the SHIFT control to sup press thc intcrference. Lrsuaìly, interference o. one sjde of the desired sjgnaì is wofse r l' r o , - . h r . u , c b " h i Ínr g l - p , . band rowa.d the cÌearer sjde reception ot Llìe desired signal can be improved. Noricet ho$ever, that the passband ol thc desired signal is also shifted, so tu..ing the SfllFT control too faf may cut off too nuch of the low or high aùdlo componentsand make the signal u.i.telllgible. signal-!o-noise ratio {redl sensitiviry), a.d w o u l d i n c r e a s e t h e l i k e L ì h o o do f o v e r Ì o a d f r o m strong sìgfaìs on other lrequencies. The lf- notch lilt.r is prjmafily uselul for -aq< .., Lpprp.' I har-rodvr- ' .$ 'p.-!tion as described later. However, ir is also a powefful tooi for suppressl.g odrer !y!es of inra-tórè-i nD r.- 8-,P-drpd buzzing noise, in the SSB mode. Afler lunjng in the desired sig.al and serting the SHIFT l o r o p L l m L t mc o p l , i f ! o u a . e r e c e i v i n g a b u z zj.g type noìse, rurn rhe NOTCH on (our of the click sto!), and {arch the S-meter while 'u-:r8 hó r. nr"ot .or rrn n. n cé t.-_ tion on.he noise (when rhe other starìon ,"t ""u- - r.r qamp.,.\-,q., | .. o After selecting the proper ATT and RF AMP settlngs, if backgrou.d noise stiÌì causes the S meter ro defÌect, note the Ìeveì and theD rotate the RF_ gain conlrol counlercÌockwise lrom maximum until the S meter deflectjon jusl begi.s to increase slighlly àbove the noise level. This rill reduce the back$ound noise when you Ìisten lo slgnals, ln generaÌ, Lhe atteDualor nay ofren be needed on lrequencles belorv i0 MHz, and when you are I s g a la 8e )ou- \.ar.o. ò ir o nolsy environment (ciry). îhe RF A\,lP should can be used ro suppress interferìng CW signals o r c a r r i e r h e r e r o d y n e sd u r j n g S S B r e c e p t i o n . t9 SSB Recepfion, Interference Reduction Excepr for the vfo and memory conrrot keys, i l g " o r r r o" p.o!idad o redu,For erm,'dé I'e \arioLr types of noise, inre.ference and dìsro.tion that ca. obstruct comfortable reception. Operation is firsr described for SSB (USB or LSB) reception on an amaleur band, wirh varjations for other modes desc.ibed later. Press the ìVIODEbutton ro selecr USb ano cune to rhe 14, 2l or 28 MHz phone band (if your antenna 1s for a band beÌow 10 MHz, selecr that band and rhe LSB mode). Atso, set the AGC-F butron for fasr agc action fdepresseo,. Ill_ AMP & Aftenuaror Careful adjustment of rhe receiver f.onr end is necessary for optimum receprjon, and shoutd be treated as fi.sr pflority ar the sÈart of an operating session! or when changing úodes, Oands or anrennas, To set up rhe receiver for optimum sensitlviiy, first make sure rhe RF gain conarol is fÌrÌly clockwise, and rhe rl amplifier a.d atrenuaror are off lRF AMp and ATT undepressed). O. a ciear freque.cy, check for any s-merer feadirg on the backgrou.d noise tevet (hiss o. cfackie). If the S-merer detlecrs above 3, t u r n o n l h e a t L e n u a t o rl p r e s s A T T ) . O È h e r w j s € , if dìe backgrou.d noise gjves .o deftection, turn on the RF AMP and again note rhe S meter reading on backgroLrnd nojse: if i! is above 3 s-units, turn rhe RF AMP back off (teaving ir on s ud t "-d.. r-r Sî - . - n o a i, 8 . o l recejved signaÌs, but woutd not improve the sig.al to-noise farjo (.eal se.sitiviryr, ano w o u l d ì n c r e a s e t h e I i k e l i t r o o do l o v e r Ì o a d f r o m srrong srgnals on other frequencies. Atter selecrìng the proper ATT a.d RF AMp settings, if background noise stiu causes rhe S me.er to deflect, nore rhe level and rhen roÈate the RF gain control counterclockwise from naximum unrìl rhe S-merer defÌecùon lusl begins to increase slighrly above the noise level. This will reduce rhe back$ound Doise when you lisren ro signals. In gene.al, the artenuator ùay ofte. be needecl on frequencies below l0 Mllz, and ùher JUu are usrng a ra.8e a.tenna or your starion is in a norsy envjronmen! (city), The RF AMP should rarely be needed below l0 MHz, unless you have a smal anlenna or your starion is in a quiet envìronmenr. Do not activate the arEenuaror and RF AMP ar rhe same rìme; i.sread, switch The seftings described up to this poinr are best for tuning and receiving weak signais u.der most conditjons. In mosa cases, once you have tuned in a station, you will wanr ro ser the AGC F off {our, slow agc) ror most comfor_ tabìe listening. If you are working a srrong sratio. (consisrendy above S 9), turn on rhe rhe atrenuator jf jt isn't already on, or rufn off rhe RF AMP {if ir's on), and decrease the RF gai. so that his signal just moves rhe S meler above jts (raised) resrìng posltion. you shouÌd notice a reducrion in background noise and more comfortable copy. When retuning rhe vfo, set rhe AGC-F back on (fast), and rerurn rhe RF and ATT to theì. preyious setrings (if you are listening for lF Shift & Notch Fitrer lf you experience inrerference from sralions on nearby irequc.cies after tu.ing in a sratìon and setring the rf conrroÌs as jusr described, Ìotare rhe SHIFT controì ro sup press the interference. usually, inrerrerence .1r .d- o. l,é dpsr- d .,grd, i. -.o-.o rna. on the other, and by shìfting the passband toward thc clearcr side receptìon ol rhe desifed signal can be improved. Notice, ho$ever, thar rhe passband of the desired srgral js aìso shjfted, so rurni.g the SlltFT conrrol roo far mey cur off roo much of the Ìo$ or hlgh audio components and n]ake lhe sìgnar uninreltigible. Tàe lF norch fìlter js primarity usefut for suppressrng heterodynes l. CW and ECSS reccp_ tron as described ìater, However, it ts also a powerlul rooi for suppressl.g orher ry!es of i.rerference, such as compurer generaLed buzzing noise, in rhe SSB mode. After turjng rn rhe desired sig.al and setrìng the S IFT for optimum copy, if you are receivj.g a burzj.g type noise, rurn the NOTCH or (our or tne ciick srop), !ìnd warch rhe S-meter whìte runrng tne notch co.rroi for mhimum deflec tion on the nojse (whe. rhe other statron lsn't talking). Of course this same technique can De used to suppress inrerferj.g C!V signats or carne. heterodyres during ssB receptio.. Note: once the NOTCH has been set, adjùsting the receìvÌng frequency or the SHIFT control will move the notch setting, which will then have to be readjusted. only work if the expected signal is strong enough to overcome the squelch threshold. Othe.wise, when not scanning, the SQL conrrol should be set flrlly counterclockwise. Another powerful application of the IF notch fllter is to effectively narrow the receiving passband by tuning the notch near the high or low edge. The result is illustrated in the diagram below, First tune in the desired signal and adjust the SHIFT as described above. Then turn on the NOTCH and adjust it to the o p p o sr e p n d o f , h e p a s r b d n d f . o r r h î r r r l e i ted by the SHIFT, for best noise rejec.ion and receiving clarÌty. Note: lvhenever using the squelch feature, make sure to set up the RF AMP, ATT and RF gain as described previously beîore adjusting the SQL control, as the squelch th.eshold is affected by these front end settings. CW Reception ln addition to the inlerference and noise reduclng conlrols described for SSB, the FTT5TGXII CW N (nar.ow) mode provjdes a 600 Hz 'f tr.p rhe cw tr fi r-r (wide) mode ro tune in the desired signal for about an 700 Hz pìtch, and then press the MODE button to select CW-N, K e e p t h e A G C - F s w i t c h i n rhe fast (depressed) p o s i t i o n f o r C W r e c e p t i o n , and reduce rhe RF g a i n a s m u c h a s p . , s s l b l e ro. suppress DacK- Remembe. to return the NOTCH control to its off (clickstop) posjtjon, and the SHIFT con t.oÌ to ìts center position when retunìng to another frequency. The CW W mode provides ùe same IF bandwidth as for SSB, but wÌth a special internal audio filter to reduce the audio bandwidth, allowing you to hear sjgnals up to about I kHz away while tuning around the band. Noise and interference are $eater than for CW-N, DuL rne wider bandwidth makes tu.ing easier. Pulse-rype nolse, ei!her shorr duration types sucl as from iSnilions sysrems and electric motors and switches, or lo.g du.ation overt h e - h o r i z o n r a d a r { r r w o o d p e c k e r r ' s) i g n a l s , c a n b€ reduced or removed by pressing rhe NB button and adjusting the NB control from counterclockwise to clockwise just to the point where lhe noise is removed. Rolating the NB control too far may cause distorrio. of the d è s r r " d . j C n a l . o r I n r a r m o d u l a l | o r. l s r o - C . igr"ìs "'p prè\èn. I n < . b ) f r è q u Fr . - \ , The NOTCH liiter is useful in borh wide and narrow CW modes to suppress a stronger nearby CW signal ìn o.der to hear a weaker one, Jus! turr the NOTCH control to set the norch on rhe undesired signal. This shouÌd be done both by ear and by observing the S-meter for a dip. Hint: when you make contact with anolher statjon on CW, press the D LOCK button .o avoro accidental frequency change. When noise blanking is not required the NB button shouLd be in the off (out) position. Squelch (AÌl mode) When waitjng for a scheduled call on fairly uncrowded band the squelch ca. be activated to siÌence the receiver until the call. Just tu.e to the scheduled frequency (or set the scanner, as described ìater, to scan the desired range), 3nd then tu.. the SQL conrrol unriì the receiver 1s quiet. Of course this will 20 AM Reception iF l-7s7(;\lI i ,l, das a 6 lH, iì,"r .or good fidelity during reception of medium-,rnd shortwave AM broadcasts. The NOTCH filter ìs Fa r ó r o d J. ó . LsèfJl or èl ninarinB.d r \ \ i i s l e s l p _ o d ' l . r d w h p t r w o s r a l t o' s a r é transmittìng near the same frequency, but when not needed, ir should be switched ofl for besL fldeLity. The SHIFT co.tÌol is ìess effecrlve than in the narrower nodes, but ìr is useful for eliminating hìgh-pilch hiss and hererodynes from sradons more than 3 kHz away. When interference or noise is severe, ECSS lfré rpd adn tFr \él-.taD F siacoodro rp.ep tion may be preterabìe for recejving AM signals. This special technique allows you to seÌect either the upper or lower sideband ol an AM signal; eljmi.ati.g inrerference thar may be present on the other sideband dLrero a nearby signal. k also provides grealer selec tivity resuLting i. grearer sensirlvity :rnd SHIFT control effecriveness, but does not provide as much fidelity for stfong signals as To use the ECSS techniquc, first rune in the starion precisely (shortwave broadcasters gen e r a l Ì y t r a n s m i t o n p r e c ì s € r n u l t i p l e so f 5 k l l z ) usìng the AM mode, and rhen select eìther L,SB or LSB, whicheve. gives besr feceprio.. I L Now carefully fine tuoe for zero beat o. the received carrier. To hear the carrier, set the SHIFT control a1Ì the way in the dìrecrion lhar gives emphasis to birss, and very slowly lu.e for the point where the signaÌ sounds most na!uraL and undisrorred, with no accomPanying whis!le or dìsso.:rnce. When you have tuned to zero bear, return the SHIFT control to center (or adjusrfor ml.imum interfe.ence and the desired tone), and push D ,qu"",. Lco( o.o.do'. lo"s",f, '( \\ r-..p H - r : T q r o b F a r r r S" ì c \ " 1 " i g n " l tio. requires a very carefuÌ rouch on rhe run. g l r 'b. qon orac .p $ In r. roe òr8nals fìrsr will make tu.ing the weak ones easier. Coarse tunirìg cannot be used for ECSS. When receiving AM signals in either ANi or ECSS mode, the noise bÌanker should be off unless it is reaily needed. Irs eflecrìveness will vary depending on the signal strengrh of rhe received signal and those on adjacent channels; beìng most effective when rhe signals dré úFak a-d roisa pu !F. -rp \r-o48. FM Receition The FT-757cXll ìs equippedfor FM operadon wrthour addilionai accessories. However, FM is gene.ally not used on frequenci€s below 29 MHz, so a VHF or UHF r.arsverrer may be used to extend the range of tlìe FT-757GXII ro rhe amareur bands abovc 30 MHz. The SHIFT, NOTCH, Noise Blanker and AcC controls are nor active in FM reception. However, rhe RF AMP, RF gain, ATT and SQL setrjngs are especially imporlant. For weak sig.aì work, set the SQL conrrol only after rhe other controLs have been set. The FT-757GXI] FM circuitry ìs designed for !5 kllz deviation, as is mosr common l. 2-way FM comnunicatlons. RTTY and Packet Reception An external TU (termlnal unjt) or TNC (termi nat .ode controiler) is required for R'ITY or packet operation, fespectlvely. Receiver audio ls best obtained from the AF OUT jack on rhe rear panel, as the ìevel of the slgnal ar rhis jack is not affected by the AF gain control. llowever, your TU or TNC musr be capable of h i g h i m p e d a n c e i n p u t ( 2 0 0 m v p - p @ 5 0 - k j ì o l r m s )r o use this sig.al. Otheririse, Ìow iÌnpedance ourprlt is available from rhe EXT SP jackJ but rl.. r" ,f è.rFo by F ^f g-rn on. .r, aro _.r . d b l p ,r h é ' r - é \ p r r L c " , L ig r i di The SHIFT conrrol ìs especìally convenienr for RTTY and hf pàcket operarìon, using the SSB modes (generally LSB is used for anareur digital modes below 29 MHz). Ser rhe SH1FT conrrot so that lsk rones are centered in the passb a n d ( t h e c e n t e r p o s i r i o n i s 1 5 0 0l t 2 ) As for SSB, the NOTCH fiÌter may be adjusred ro suppress an unwanred carfrer, or ro narrow the passband af.er the SHIFT control has been set. Thc agc should be fast (AGC F dep.essed), and the noise blanker may be left on ar a moderale setting (abour 10 or 11 orcÌock). TRAI.ISMITTER keep the METER swltch on *ìe FT-7s7GXll in the ALC (undepressed)posilion. See the Tuner or { T p l I ' e r i r u a l o - . o m p l è r èd e t a . ì ò . OPERATION The solÌd state rransmitter in the FT 757GXll .érr'.g r'è r è q u r è s ' 4 r d - u " r m eI o l F | h r r desired output level. The maximum poríer outPul is determined by the mode and the capabiÌìly of the power supply (in AM, FM and alsk, power may have to be restricLed to avoid overheating the power supply]. Also, there are certain precaurions ro be observed at 3lÌ Èimes when transmÌtring to avoìd possible damage to the t.ansceiver, and to assure a clean signal. Keyjng the Transmitter Use the MOX button to activate rhe rransmirter d u ' n g r h é f o l l o s n 8 p r o . è d u r è. B F o r è b F g i l nin& s€r the BREAK lN swirch on rhe top panel to FULL, and the VOX button on the front panel to off (out). To tra.smiL, seÈthe MOX bìrtron . o r h a a e D r F c . c op o \ i r i o n . d n d t t F - p r p r s I again to .eceive (undepressed position). Never transmit withouL having a dummy load or anrenna tuned to the operatlng frequency connected to the transceiver (or linear ampli fier, if used). If you have any doubl of the suitability of a pa.ticuÌar antenna on a cerrain frequency, check the swR (standìng wave Ratio) first, SWRChecking This procedure checks the approximate SWR using jùst a few (arrs, ro avojd inte.le.ence ard srrain on rhe equipmentwhen SWR is ùnknosn, such as on a new a.renna. as described below. ( r )O n q ! o i d r d n g i o t r p q L pr c c ' ' . r g r r a n 5 m ' s o\ - . First return to receive, tune to the new transmit frequency, and listen for at least a mi.ute or two to make sure Ìt is not already the rear panel, set the FWD-REV sLide switch ro the FWD position, and turn the FWD SET control lully clockwise (as viewecl occupìedi or ask if the frequency is occupied and then listen for a response, When using a lighl- or medium duly power supply such as the FP-700, do not attempt to lransúit FM, AM or fsk at full output power. Although Lhe transceiver is capable of this, some power suppltes are not, and they may rapìdÌy overheat a.d be seriously damaged. In any mode, feel Lhe supply occasionalÌy !ìnd reduce power or slop transmitting for a while iî it feels hot. 12) M a k e sure the DRIVE control ìs ser fully counterclockwise. Set the METER switch to the PO (depressed) posilion, and seiect ( 3 ) Tune the vfo to a clear frequency, and listen for a minute to make sure its ciear before proceeding. ( 4 ) Press rhe MoX Never begin to transmit (except into a dummy load) without first listenÌng for a few m,nutes to make su.e the frequency is clear, and then transmit your callsign. This wiLl avoid accidental interference co other stations' button (the red oN AIR indicator will light), and ve.y gradually advance the DRÌVE controÌ whiÌe wàtching the meter for any detlection. Now adjust rhe DRIVE LonrroL io llar rì . îè èr dé flecls exactly to the SET marker (white SWR Checking & Measuring line cufting the red bar at the rÌght side of rhe swR meter scale). Before transn1itting, the SWR of the anrenna . ) q r e r ò n o u l co è ' h ó . P p d è r l f È o p F " d r r n gl - _ quency to ensure that the proPer impedance is being presenled to the transmitter. The trans_ mitter includes protection circuits that will automatically reduce the output Power if SWR is hlgh. For example, with an SWR of 3:1 only a b o u t 7 5 o l oo f f u l l p o w e r ì s a v a i l a b l e , ( 5 ) Set the MOX switch back off (our). Reach back around to the rear paneÌ, and move rrè fr^D-R \ ' id. .i r.i' o | - IrtV po.i tion. Now press the NlOX swìtch again to key the transmìtref, and note the SWR approrimatìo. on the bottom scale of the meter. Press the MOX switch again lo return ro receivel If using the FC-?5?AT Automadc Antenna Tuner or FL 7000 Linea. Amplifier, SWR ìs calcuÌated and displayed automatically, and rhe foÌlowing procedures are not necessary. ln this case, It the SWR indicàtion was above 3, the antenna syslem is too far fron resonance to be used at the test frequency v'ithout substanlially degradedperformance (not recommended). SwR 22 ( 1 ) With the MOX swìtch off, select the CW-W node, ser the METER svilch lo PO (Ìn), and wse sè. rhé DR.vr ' orr'ol fJl ) .lo (maximum). On the rear panel, set the FwD- indicarion close to 3 indicates a poor antenna match at this frequency, but an antenna luner such as the FC-7574T may be used to match the anrenna better, .educing the swR. of course r h s w l l n o t c d r g ó h ó r a d i a r i, g q u d l r t . p . of rhe antenna itself, and will require retun_ iò i r g w n è r F r e r ' h è r r d - \ m i n g f r p q L e. \ a n l e n changed, so it ìs better !o correcl the na or feedline mÌsmatch firsl, Ìf PossÌble. REV switch to FWD. then press the MOX button and carefully adjusr the FWD SET control on the rear panei so that the meter indicates 100W or rhe PO (center) scale. Return the MoX button to 12J C h e c k t h a t t h e f r e q u e n c y ì s c l e a r , SWR indications of 1.5 or less lndrcales a matched antenna for use at the test frequency. The accuracy of this calibration is very rough, as the actual fulì power output depends on the band of operation and the antenna SWR. If you have an accurate wattmeler and 50-ohm dumdy load, you can use these in lhe above procedure. Set the DRI\E contro] for l00W output before adjusting the FWD SET control. SWR Measuring Use full (l) power to measure SWR nore preclselv: set rhe FwD SET control on the rear psner to midrange, and set the FWD REV swirch to FWD. use the CW W mode and MOX but1ionas above for lhe following sleps. SSB Transmission Wilh a microphone connected to the MIC jack on the front panel, ensure the folÌowing controls are preset as indicated: (2) Set the METER se'itch to ALC (olrt). (3) Make sure ùe frequency is clear' and Úen press the MOX button and advance lhe DRIVE untÌl lhe meter jusa begins to deflect, Mc. ta Al C rourì l2 o'clo"' . !1l. gar'ortro, (inner krìob right of the MIC jack) (4) Press the NIETER svitch to PO (in). {5) Whlle still transmifting, carefullv reach around to the rear Paneì and adjust lhe FWD SET controì fo. fulì scale dellection ro the 5ti mdrk on tfe merer. PROC sv rrch \o\ stir' I MODE . (6) Move the FWD-REV switch to REv, and note ùe SWR reading on the bottom scale of the merer. set the Mox button off (oull. OFF (out) oFf loulì select LSB or USB Tune ro a valid tra!smitting frequencv (in lhe Again, ìf the SWR is above 3, a change in the i -e'on 1 a_o Power Meter \è F.ro cLose lhe PTT To activate the transmile., switch on the lilcrophone, and watchiq the ALC indÌcarion (blue scaìe) on lhe meter, adlust the MIC gain conlrol so that the meter deflecrs within the ALC zone (heavy blue line on !he scale) o. voìce peaks. ThÌs wiÌl resuÌt in full power output: reduce the MIC gain to Calibration The meter may be calibrated using the ClV node to indicate approxìmate transmitter RF ourput powe. in eatts as follows. lhis is necessary for prope. tra.smitter adjustment for AM, FM and RTTY or packeL transmission, and is help_ ful for reduced power operation in olher modes. lf using the FC-7574T Antenna Tuner this procedure is nor necessary, ds the ìrC757AT includes a wattmeter and dmrìy load, Speech Processor After setling the MIC 8ai. as above, press the PROC switch to activate the processor- The average ALC indicarion on the mere. will in crease, but if the peak indication deflects palr rné al. / o n è . . c d u ' - r h è \ 4 l C C d rr . Before beginnin& measure the SWR as described above and make sure the antenna is properìy matched, or connect a 50-ohm dummy load. 23 The COMP LEVEL contlol on the rear panel adjusts the level of speech processor co'npres sior, and is carefully set for optimum performance at the factory. However, usÌng difÍerent microphones or variations in voice prtch mav make it desirable to readiust lhis control. This can b€ done by monitorjng the transmitted sigral on ar os,i los(ope or èxrerlaì receivp- The FT-?5?GXII incorporatesa specialrclaîifier menoryr, which alìows you to lisren on the transmit frequency by swilching off the clarjfier. As long as you donrt touch Lhe tunÌng knobJ pressing CLAR again returns you to rhe {offset) receive frequency, When the contact is finished, remember to switch off the clarifier so that lhe transmit and receive frequencies and modes.,vill be realjgned when yoù retune. and adjusting rhe COMP LEVEL control to the point just below that at which distortion appears on the signal. lf set beyond this poinb, average porÀ'er will still be increased, bur disrorrio. will cause signal intelligibil Cw Transmission ity ro be decreased. The FT 757GXIl offers bolh semi and ruìÌ break in (QSK) operation for both simplex and spliî-frequenct op€ratiotu Hose!er. QSK opera r i o n m u s r n o r b e a r r e m p r e ds h r l e ù . r ' ; a linear amplifier nor specificall! desianed lor r, or aamaSèro thc ampllfier or rransceivel may result. see page l{. VOX (Voice actuated T.ansmjl Switchingl ln any of the voìce modes, you can use the VOX system to automalically activate the transmit Pless ter rvhen you speak jnto the microphone. the VOX switch to activate VOX, a.d then adjust rhe VOX conlrol on lhe rear panel so that the transmitler actÌvates when you speak s $ i . r o 1 ' r r èT r ' a r $ . r h o ,I p r e 5 ò ig . h è P l p o n r . \ 4 ' e n ) o s r o p d l t . r g r r P r r . n s ie i v c r should rerurn lo receive alter a slight delav. The DELAY adjustment on the rear panel sets the hang tjme for VOX switching trom transmit The FT 757GXll incÌudes an internal electronic keyer, which can be used by connecting keyer paddles to the KEY jrck. You can also use a slraiSht key or an external eìecironic keyer, in which cases the internal keyer must be switched off (top panel KEYER switch to MAN). Be careful not to shorL the outer contact of the KEY jack to chassis ground. lf the audio from the receiver lriggers the VOX system, make the above adjustments wtth rhe AF control set lor low voÌume. Then increase the volume to the desired operaling level and adjusl the ANTI-TRIP control on the rear panel jusr to lhe point where receÌver audio fron the speaker ceases to triP the VOX. s-r up rhè VOX switch oN (dPpressed) M E T E Rs w i t c h ,., DR\l Clarifier (ReceÌver ollowrng Í_o t pa pì .on, o \: ALC (out) lo.-rr.F (nd') 'o,trol Orfset) MODE switch . . , . . select CW-W or CW N When receiving on a vfo, the CLAR butron can be pressed to allow independent tuning and mode charging of the receiver wùhout affec_ ting the transmit frequency (CLAR is dlsPlayed to the left of the operating frequency). This feature is useful it, after making contact his transmitter drìfts; with anorher statior, you can retune hÌs siSnal without changjng y o L r o ú | r r a n s nr , i n g l f è o u F n c ) . A l ' o , .è the range of the cla.ifier is unlimited, iL can be used for spìit frequency operation. A1so, o. rhe top panel, set rhe KEYER switch ro MAN initially. Close the key to activate the tra.smltter, a.d adjust the DRIVE conlrol so that the ALc meter jusr starts to deflect. This se.ting provides full power output: after making contacr with another station, reduce power wlth the DRIVE control if you can wirh our roosrng conracr. You should be abLe to hear the sidetone from tlre Ìoudspeaker (or headphones) when you close 'I While the clarÌfier is on the tuning knob and the mode seleclor affect only the receiver: m o d e w i l l r e m ain rransmitting frequency and the same as before the clarifier was activated, and this frequency and mode will be displayed rrhen transmilting. P , èr.np .în .i, lilr,oe rhe hole near the rear of the bottom cover) can be adjusted for comfortable sidetone volume. 24 To ser the (internal) keyer speed or to pracrice sendjng CW, set the VOX switch off (out), and the BREAK-IN switch to SEMI. Also set the KEYER switch to AUTO if usirg keyer paddles. Now, cìosìng the key will generate the sideAdtone buL no signal will be tfansmirted. just the KEYER control for the desired speed, AM Transmission For QSK transmlssÌon set the VOX switch OFF (out) and BREAK IN to FULL. though this does not show on the meter. Because carrier power is only one fourth of rhe totaL PEP of an AM slgnal, it must be limired ro 25 watts or less when transmitting lith the FT 757GXII. When rhe power Òf the îodrlar,lB . apbard" is dddeo ro rhÈ cd rier nE' -. ..r a Pl P o-.p.r rs 100 wart . dì- To adjusr rhe FT 7s7cxll for AM transmission, first calibrate the PO meter as described on '\rè--dr$arlmerp.. pdgè h orupc For semi break-ln operation, as required wjth sorìe linear ampÌifiers, set the VOX switch ON {depressed) and BREAK-IN ro SEMI. The DELAY control on the rear pareì adjusts the hang time betwee. key up and receiver enable. (1) Preset the MIC gai. fully counterclockwise, and ser the METER switch lo PO. t 2 ) Make sure the frequency is clear, and then FM Transmission close the PTT swilch on the microphone and advance the DRIVE for power output of 25 \ldt s or lers 0n Lhè .rdlsÎirlpd i ar- èr, For FM transÌ]]ission, just select the FM mode ard close the PTT swltch to lransmit. The MIC gain co.trol ls disabÌed for FNl, as the galn 'rpl t.pr r: o_-sFr iì pr o r . è ' n r c r o jh o r ' naìly lor 5 kHz deviarion, and should require no iurther adjustment. RF power outpul is adjusted by the DRIVE conl.ol. Ior full power output (using the FP 757HD porver supply), adjusr the DRIVE so that the meter (set for ALC) just deflec|s slightl).. When contact is ( 3 ) Set the METER swirch ro ALC (out), Speak into the microphone and advance the MÌC gaÌn control untjl slight movement of the meter occurs on voice peaks. PEP outlul is now 100 warts. Do not advance the MlC gain further, or overmodulatìon (and disroruonJ may resull. estabìished, reduce rhe DRIVE, ( 4 ) Use the DRIVE control |o reduce power once contacr has been established. The Al speech processor can be acrivated for A M L r a n s m i s s i o n sb y p r e s s i n g t h e P R O C b u t t o n . ì:lowever, if speech processing is necessary to maintain conÈact, we recommend switchirg to an SSB mode for higher efficie.cy. CAUTION When the Fî-757GXII is used with the FP757HD power supply, full power Flvl, AM or AFSK (RTTY) transmìssions must be ìimiled ro 30 minutes maximuÌn, The VOX systen and cìarifi€r controÌ can aÌso be used for AM, as described for SSB. P-700 o, 4.1èr rgfr'drr) thè supply is used, rransmi!ter power i. the above modes must be iinìted ro 50 watts at all tjmes, to avoÌd overhearing and subseque.t damage to the suppìy. \4nè The AM CAR control on the rear panel adjusts .ìè ìudr d io p-r.è r'àgF Ìevel. This contlol is alìgned at the factory to provide 100% modulatio. rlien the DRIVE cont.ol is set for a carrief leveÌ of 25 rLF \44 g';r .on -n J .pL ro about the same !osjtion as required for full power output i. SSB, For 100% modulation with a lower carrÍer ìevel, the AM CAR cont.ol can be readjusted with an osciÌloscope connected to monitor the llf outpur. Regardless of the power source or node, we recommend reducing power lron the maximum leveÌs mentioned above whenever rransmitting for more than l0 minutes, or if the ambienr air temperarure is very hot or the power supply feels hot. To set the AìU CAR control fo. i0090 modulation al fulÌ po\yer outpu!, use an RF voltmeter for the following steps; 25 milt€d signal. SeÌecl LSB or USB mode' and set t|e PROC switch oft. ( 1 )Connect rhe RF vollmeter to jack J1023on the RF Unit. The PTT jack on the rear panel mav be used lor of press external transmit/receive control, the VOX butlorì to al1ow auromatic transmlt/receive svitchirg (eilher full or semi breakin may be used). Manual transmit/receive control is aLso possible with the MOX button. \ 2 ) Select a CW mode, and note the vollmeter reading with the !ransmifter keyeo ( 3 ) Return to receive, select the AM mode, key the !ransmitter and wÌth no modulation' adjust the AM CAR potentiometer for as exactly one half of the voltage that measured in the CW mode. Note that the dispÌayed frequency is the (suppressed) carrier frequency, so vour actuaÌ MARK and SPACE frequencies wiLl be displaced fronl the display by the audio frequencÌes of Use the MIC gain control to adjust power ouLlor full power' sel put while transmltting: m eter lsho\jng ALC) g a i n r h a t t h c so the l\'flC dellec!s sÌigh!Ì1. Reduce po$er output br lurning the \llC gain counrercìocli* ise Írom fuÌl po$er and obser\ing pose. ou!put on the PO meter (after caìib.atÍng as described pre\,lously), or on an externaL wartneterA s m e n t i o n e dp r e v i o u s l y , t h e F î - 7 5 7 G X l l i s c a p a b L e of fulL power AI-SK ùarsmission for linited periods rvhen used wilh a heavy duty powef supply. Restrlcl rransmissions ro 30 minutes with !he FP 75?llD. If using the FP 700, restrìcl RITY or packel power output io 50 watrs maximum. Howeler, ìf ihe àir Lemperatue is high o. ar hìgh aÌtitudes, cooLing eificiency is decreased and so power output should be feduced accordinSÌy. Also, it is a good Prac tlce to back ofl on úe porver whe.ever maKr.g a long transmission, and even then supply tem Unless usÌng a heavy dutv power supplv' Keep \ ì^fi, d4d . loD ra rsffil'.rb ùc power supply becomes hot. RTry, per.ìture shouLd be closely monitored. HF Packet & SSTV TransmissÍon al \ Lè r dnrrir';-t. rt r'r' ' ool " o f f u n lil the set s w i t c h P O W E R t u r n t h e don't a n d the lan t o c o o l has bad a few minutes Transmission ot narrowband FSK (F1; RTTY' SSTV an<1 BelÌ 103 HF packet) requires input of equal ìeveÌ audio tones (AFSK) ar the 600 ohm Remove the PATCH jack on the rear panel' micfophone fron the MIC jack so thal extraneous sounds do not inlerfere $'iLh your trans- 26 MEMORY OPERATION (a) Ten nemo.y channels, nunbered 0 through I, are available for storing operatÍng trequency aùd mode of emission selected on a VFO. In addition there are two VFOS denoted VFO A and VFO B and a r c Ì a r i l l e r m e m o r y ' , e a c h o f w h i c h h o l d b o L ho p e r a l i n g frequency and mode independently, giving a total of l3 memories. Selection and manipulation of the memories and VFOS is accomplished via the six keypad keys at the upper' riSht corner of the Now receiving is on VFO A, but wher the PTT switch or key is closed, lransmission is on VFO B. fo reverse rransmil and receive frequencies (for example, to listen on lhe ùansmit frequency)l just press VFO A/B. PressSPLII . An dtr.r.dl \Ò frel,od ro opF-atF\pti. ir ro Lrsè one vfo and the clarifier, Ìnertioned previously i. the SSB Transmission sectior, Tune the vfo to lhe transmit frequency, lhen press CLAR and ítne ro the receive freque.cy (and other mode, if re Note that rhe VFO>LI and M>VFO keys have yellow markìng i. the notch on the keyfaces. This is caution tha! these keys intended to (erasedl. dara ro be overwritten cause To iisten on the transmil frequency, press CLAR again, a.d then once more to retuÌ. to the receive frequency (which is srored in a 'clarifier menory'). Note, however, that the cÌarifier memory is Ìost if rhe írning knob moves while checking the transmit VFO A/B Selection The operatingvfo is indlcaredby VFO A or VFO B displayed to the left of the operaring frequency. Memory Storage Each vfo holds an indepe.dent fiequency and node o l r î i . s J . o \ p l a ,I t n F a . t n r - d l è \ f o . p - a s l h F VFO A/B ker. ThÌs procedure aìÌows storage of the vfo mode and frequency into a memory channel; VFO/Memory Selection (1) Set the VFO ro lhe frequency and mode of emission to be slored. (2) W h i L er e c e i v i n g , p r e s s M R / V F O t o s w j t c h lrom vfo to memories. (3) Press the D\ryN/UP keys, if necessary, to seLect an uùused memory clanneì (default data is 7.000 MHz LSB Ìn all (4) Press MR/VFO (5) Press VFO>M (lower center) to write the data from the vfo to fte memory. The MR/VFO key at the upper riSht selects be rwee. memory and vfo operation. wheneve. this key is pressed, the selecled vfo or memory and i t s d i s p l à y e d f r e q L r e n c ya n d i n d i c a t e d m o d e a r e srored (except wirh tempo..rry memory modes, descfibed beÌow), rvhlle operation shifts from vfb to a memory channel, or vice ve.sa. The vfo or memo.y channel rccalled is always the one that was last used. (When a memory channeÌ ls sel ected, rlvlRr appears to the left of lhe djsPlayed frequency, and rCHr appears to the ri8ht, wìth the channel nLmber be.eath it.) Split Frequency Operation The two vfos and the SPLiT key can be used for splil frequency ope.ation as foìlows: again to return to the (l) Press VFO A/8, if necessary, to select VFO B (displayedat the left). Note that the VFO>MR key overwrites (erases!) the prevìos memory contents. Steps (2), (3) and (4) are required onÌy to select the memory channel rhar is Lo be written. If you already k.ow that (2) Tu.e rhe lasl selecred memofy is free data, these steps can be skipped. (3) Press VFO A/B to select VIrO A, and tune to the desired .eceive lrequency to ihe deslred transmit frequency 27 lo accept new mitted signal. Select LSB or USB mode, and sel the PROC switch off. (1) Connect the RF voltmeter to jack J1023on rhe RF U.it. The PrT jack on lhe rear panel mav be Ùsed for or press controì, external transmit/.ecejve the VOX buúon to allow automatÌc !'ansmit break/receive swÌtching (either full or seni ifl n1ay be used). Manùal transmil/recerve conrrol is also possible wìth lhe MOX button' voltmeter \ 2 ) Select a CW mode' and note the reading with lhe transmitter keyed' ( 3 ) Return lo receive, select the AM mode' key the tfansmitler and with no moduìation, lor adjust the AM CAR potentiometer was exactly one half ol the voltage lhat measured Ìn the cw mode' Note that the disPLaved frequencv is the (sup pressed) carrÌer frequencv, so vour actuar MARK and SPACE frequencies wtlL be displaced from the display by lhe audio frequencies of Use the MIC gain contfol to adjust power oul for lull Power' set put while transmittìng: the \,flc gain so thar the neter (showing ALC) deflects slìghtly- Reduce power output bv tLrrning the VIC gair counlerclockwise lrom fuÌl pover and observì.g power outPÙr on the PO meter (afrer calibraLing as described previously), or on an erternal wattmeter' A s m e n t i o n e dP r e v i o u s l y , l h e F T - 7 5 7 G X I ] i s c a p a b l e of full power AFSK ransmissìon for Ìintrcd Periods when used with a heavy dutv powef supplv ReslrÌc! transmlssions to 30 minutes with lhe FP-757HD' lf usìng the FP 700, resrict RTTY or packet power outpu! to 50 warts maxlmÙm. Hotever, if ùe ajr temperature is high or aL high aÌurudes, coolLng efficienc), is .lecreased and so power oulput sbould be reduced accordirglv. Also' Ìt is a good prac tice |o back off on the power rvhenever making a long tr.ìnsmission, and even ùen supply rcn1 Unless using a heavy dutv power supplv, keep rd òloD rra 'ri lrdniTlJsiu the power suPPlY becomes lioL t rg ' RTTY, HF Packet & SSTV Transmisslon peratufe should be closely monìtored of narrowbandFSK {F1; RTn, SSTV Transmission r\fter !ransmirti.g. il the cooling tan rs on, don't tufn the PO\\'ER s\!itch off until the sel has had a fe$ minutÈs .o cooL and the tan and Bell 103 HF packel) reqÙires input of equal Level audio Lones (AFSK) at the 600 ohn1 RemÒve the PATCH jack on the rear paneì j a c k t so hat ex'ran microphone from rhe l\4lc eous sounds do not interfere with vour trans- 26 be set for Èhe desired sensitiviry belore adjnsting the SQL controÌ, as these will affect the squelch Memory Recall (l) \2) Press MR/VFO to recall memories: the dispÌay and mode indicators wilÌ change to the last memory channel accessed. \4ODl I re S( \\ rhe .canrinS modes, durÌng which rhe VFO A/B and MR/VFO keys adopl aìternate functions, as explained below. While watching lhe displayedchannel number press the DWN and LrP keys to select different memory channels. Memory Channel Scanning To scan the 10 memory channels: The mode ol emissìon of s recalled memorv channel may be changed temporarily by the MODE keys. when another memory or vfo is selected, the temporary mode seÌection is cancelled. Changing rhe f r a q u e n ') o r h è s r o r è d n o a è 4 f r h è n e r o r \ r è q t j r e J (1) Preset the SQL control |o the point where background noise is just silen- (2) Pr"., \aR/VIO ro rp.a (31 MODL. ara \.rR./VfO agdrn Prèss \Cq\ to start me scanner. restoring from a vfo. rh, npmoria). Changing Memory Mode & Frequency To change the data stored in a memory chan.el it is rìecessary to shift Lhe data to a vfo where it can be nanipulated. (l) Press r\aR./VFOand the DWN/UP keys to select ùe menory to be changed. (2) Press MR/VFO agaln to return to lhe vfo (either A or B: data wilì not be Ìost). Scan.ing will pause on any channel having a signal strong enoùgh to open the squelch, ard will resu,'ne again if lhe signal drops out. lvhile paused, if )ou press MIVVFO a double beeP will sound and operation wiÌÌ shift to úe neat higher_nlmLìered (3) Press VFOZzM to exchange the vfo and memory conren$. To slop lhe scan.ef nanualÌy press MR/VFO or the PTT switch morn€ntarily. Return the SCAN MODE swirch to the off (ou, positlon to return the vfo/memory keys to thejr sLandard functions. (a) Now retune or change node as desired. Scanning Between Vfos (s) Press VFOZM to exchange the vfo and memory agaÍn, restoring the new data from the vfo to memory, and orìginal vfo data back from the memory to lhe If you set up the vfos as scanringlimits, you . an ., dn aìì rr-quèr ie in bè,bóér b) p éo\i t SCAN MODE and the. VFO A,/B while operating on a vfo, Press FAST to select high-speed scanniù9. Sca.ning wìÌì pause on a signal and resume if the signal drops out (or manually, by turning the SQL clock\rise). Pressing VFO A/B while paused moves the ffequencr-' one srep. If operating on a memory a.d you don't care lo preserve the vfo data, you can lusl press jvl>vFO to copy the memory channel data to the lasL seìected This leaves the memory data intact, bur vfo, overwrites all data 1n the vfo and leaves operàLion T o r " . " 1 . .. . o p . r'g u'd .è rl-c -,c,,a vfo to .he displated f.eque.cy, press VFO A/B o. the PTT ssitch morìentariÌy. To canceÌ scannrng alrogethert retun SCAN MOIIE to the out SCANNING Programmable Memory Scanning (PMS) When the squelch control is adjusted to siÌence the receìver, either the memorjes or a preselecred "rèquen.) -pgm-r, mév be ,c- r-d a,,on"', 4 ì/. Signais that are srrong enough to open the squelch Note that the RF AMP wiLl haLt the scanner. and ATT swirches and the RF (gaìn) control must The Pì\']S feature alÌows you to scan aÌl frequencjes between úose stored in any two adjacent memory channeìs. The starting freqùency and mode of the scanner are determìned by the seìecrcd memofy 28 channel. Slow and fast (x10) rates are selectable as lor vio scanning, Which ever vfo was last selected prior to activating PMS wÌll be changed by PMS numbered memory, or UP key to scan to the nexl higher nmbered memory. rPr wìll be displayed in place of ùe memory channeÌ number, indicating that rhe PMS system is now acLivated. To use programmabìe memory scannjng; ll) 5 or. rhè loue' ara pDF. \.dn ing limjts in adjacent memories, and seÌect the one you wànt to start at, (2) Preser the (3) PMS scanning wìll pause automatically when the squelch opens, or can be nanually halted by the PTT switch or DWN/UP keys: the PMS function remaìns active (rP' stilt displayed).Press DWN or uP again to resume sca.ning. SQL control to the point When the SCAN MODE switch Ìs retuned to off (oul), PMS scan.ing ìs cancelled and normal oper ation resumes on the Last-selected vio, which will be set to the frequency and mode last tùed during P.€ss SCAN MODE on, and the. press the DWN key to scan b the next lower P.ess whjÌe feceivi.[.. a !rì to swirch to rhe !ÌîenaLc vfo, A l s o , r v l r e nS c à r l l o d e o . , s t a r t s Pfess while receivj.g on a vfo io ùse the selected rlo ior feceiving, aód the aì!ernare scanning b.t$ecr vfos, and stéts/s!oress.a.ned f.cquencies. vio ior transnirtinS. WhiÌe receivnrg, press to srvirch o f e r a d o n b e t q e e nv i o a n d n e m o r y . / \ r s o s r a . | s / s t o p sn e n o r y s c a n n r n gd u . i n g s c a D l \ 4 Ò d e . VFO A/B SPLIT M R /\/FO rr'FO2:/M VFO>M M>VFO rlffir rEE P.ess shilc .ecejvrng ni er c n a n g er t o o r n e m o r l c o f t e n $ ! . i t h r h o s eo f Ì . s t s e i e c i e dù c m o.y o. vrì. Ch..ses operating P..ss while.eceivrnE o. a !ao to rv.rte conle.rs over last s eI e c t e d n e n o r y . O p e . a t i n g t r e q ù e . c ) d o e sn o t c h a n g e . 29 P . e s sw h i l . r e c e i v r . go n a r n e m o r y ao wrire co.rents o!e. Ìaslsele.ted vlo. Ope.arionshifrs CAT SYSTEM COMPUTER CONTROL The CAT (Computer-Aided Tuning) Svstem in the FT-757GXII allows control of the ffequencv and mode ol vfos and memories' selection berwee' theú, and signal slrength detection and scan by the operator's exlernal perning confol sonal compuler. Uni or bi_direcrional serÌal dala is passed via the CAT jack on ihe rear as folÌows: panel of the transceiver, DATA RATE: START BIT: DATA BITS: STOP BITS: PARITY: 4800 bits/sec ó 2 The chart at lhe boltom of this page shows tne entÍre data sequence for one CAI conmand' Data is transmitted from the compuler to Lhe SI (Serial Input) pin (pin 3 of the CAT jack) lrom left to right in the diagram So' for example, Pafameter (Parm) 4 of the cofìmand Bìock EXAMPLE: to set 14.25000 Ml'lz as the currenl oPerating frequencY; is sent first. Aìl data blocks sent to the Note: must be five bYtes Ìon8. Norice that, for lrequency parameters' the 100 MHz digir must be present and set to zero for ffequencies below 100 MHz. Also notrce maL decimaÌ lrequency data musL be translated rnto BCD (binary-coded decimal) digits for sending, and that the LSD (least signiiicant drgrt, Parameter ,1, 100rs and l0rs of H,) Ìs sent 7:7 Return Delay and Read Status Commands The Instruction Code sent by the exterraÌ compuler at the end of each s-bvte Comnand Block is the 'oPcoder that instructs the FT-757CXll what actio! is to be performed. The lnslruc tion Code Chart on the next page descfibes (unListed) each valid Comnìand. If an invalid command is senl, or if invalid pafamelers are recognized, lhe transceiver wiÌl ign're the A I b r r r r u o l h é l r ' r r r ' r . o r 'o f _ r j _ directional; from !he computer lo the !rans .èi\ar .rl). l\e br-ai è'rrorà ' s ru riors are lhe Return Delay and Read Status commands, which have no elfect on operation of the FT757CXll except to cause il lo return currenl operating status informalion on rhe SO (Serial OLrtput, pin 2) line to the computer (alrer a specified delay). Thls data alloii's rhe compu- Notice that most lnsLructions reqùire onÌy o'e Hoù or no arguments in the Paraneter Byles f h e FTt o ever, every Conrìand Block sent 757CXll musl àlways consist of five bvtes. The unused parameter bytes will be Ìgnored wherì such lnstructions are executed' so their value is irfeLevanr (rhey need nor be zeroed). rer to check the starus ol the transcelver' and so lhe program should send o.e of these commands ro verify the transceiver state after each series of i.structions. Also, the Read S t a r u sc o m m a n d i s s e n t l v i t h a 0 l P a r a n e l e r r o read the digill2ed siSnal strength indrcatron CAT Data Byte START B]T DO D1 (0 ro 0Fh). SYSTEM T1MNG CHART D2 D3 D.l D5 D6 D1 STOPBITS l2) Code (MSD) Block * l00msfvlAx Aiter ùe Rerurn Detay or Read Stalus comma.a nas Deen sent, the rransceiver wili waìt for 0 to 255 ms, as ser by parameter I of the Retur. Delay comnand, ro a|oiv enough .ime for rh€ conìpùrer program to ger set ro .ecejve the status dara. The transceiver then rerurns eirher one byre (if Paramerer I is set ro 1 ì. ùe Read SLatusconmand, tor the S merer rndr catio.), or 75 bytes (for complete status informarion on the vros and aI memories). tn r l _ è r d r- r . a . - . 7r oy -, r" ,-p arated by rhe detay set by rhe tast uùre rne Return D€lay commandwas sent. Note thar 75 bytes are always returned after rhe Relurn Delay command, as well as afrer rhe Read Srat_ INSTRUCTION us command (wlrh Paramerer 1 = 0). The Starus Update Chaft and accompanying tables show t|e formar of rhe 75 byres re turned after rhe Rerurn Deìay command, or when the Read StaÍrs conmand is sent wìth a u pa.a_ merer: noLice rhar some flags bit lields ìn the fjrsr starus byte. 'fhe CAT jack atso provides access ro the pTT (Push To-Talk) ljne ar pjn ,1 to allow Key,ng 'Ihis the transmirte.. pin has 8V DC on it wnen open-circui! (during receprìon), and ac_ tivates the transùjtrer when grourded (sour cing 8 mA). CODE CHART NOTE: Cornmandsai:e sent in the REVERSEof the order code ( llex) MSD SPIIT 14R 2 l a2h p1 = 00 (oFF) or 0t (oN) pl = 00 - 09 (qtranneÌ No) p 00 09 (channel No) 04h 05h pl = 00 (qFF) or 0'l (oN) M SWAP IlODESEL 0ch CLARIFIER IIGSEL RETURN DEIAY FEAD STATUS rx * - D2 p1 p t = 0 0 ( c s N ) o r o 1 { H A r tr l pl Pl witÌ determined not affect by current DeÌay betlreen response bytes DELÀY or READ STATUS conmand. *** This Byte pl 0Dh 0Eh t0h any vaLue: byte aand steps !1 = 00 (A) o. 01 (B) p1 = 00 - 09 (ChanneÌ No) Step up one Band+ dolln one Band* !!e! trl = 00 (OFF) or 01 (oN) Frequency Set ( see ExMpL ) S w ap V f O a n d M e m o r y p'l vaÌue: 00=LSB, 01=USB 0 2 = c w w , 0 3 = c w N , 0 4 = A r 1 ,0 5 = F ! 1 06h 07h 08h 09h 0Ah 0Bh FREO SEî+++ connand 1, Bit : chart. 4 LSD 01h D LOCK VlO A/E U VFO BAND UP BAND DI{N shown in tnrs onty functions (MR/vfo flas)). - 00 to FFh ms detav** = 00r or 0l (Meter onÌv command function. Ean/cen from seÌectron: transceiver Eam bands, or 0.5 t4Hzafter ùhen operating on a vfo p a r a m e t e r s n u s t be in receipr or (test starus ÈCD fo.nat. RETURN Update STAÎUS UPDATE CHART (fornat of data returned by 757cxrr aftèi REîuRN DEI-AYconnand, or READ sTAîUs conmand RefTable 1 contents Statqs 2 Flaqs scaN MoD!* (0o=oFf. 8oh=oNì l 4 5 6 9 Band Dàta èÌectèd Mènory channel No. operali4s (BCD) Frequency 2 TABLE (O 9l : Byte t0 1-14 lFo A Freqtredcy {BCD) 26-29 30 Menorv Clanne1 Memory Channèl Ranqe 3 15 1 6 1 9 vFO B Freg-ùency(BCD) 20 2 1 - 2 4 clarifier Frequebcv IBCD) 2S cÌa!ifier r4ode** 0 Frequèncy 0 Mode+* o2 3 03 a4 05 06 3 {BcD) 3 samè tormat as 26-10 a1 36-40 same format as 26-:01+*+ same folmat as 26-30 same forma! as 26-30 08 09 46-50 M@ry ch 5 56-60 66 10 Menqay ch I 11 75 Indìcates with lhe position of sane namè. folnat format fornat fornat front as as as as 26-:ì0 26 30 2 6 -.10 26 30 panèt Byte vaLues a!è lhosè indicated ia !hè lnstruction Code Char!. 2.5 4-0* 7 . 5 - 10 . 5 10.5- 14.5 14.5 18 . 5 18.5- 2t.5 2 1. 5 25.A 2 5- O 3 0 .0 * hish end of each band iange is actuaÌly 10 Hz belorìr the freq shown- same format as 26 t0 sane sane sane same fMEz ) 01 .ll-f5 41-45 BAìID DA,TA swalcn for Modes calculaLe Menory channel adalresses by; Channet Freq lndex = (ch No. x 5) + 26 Channel Mode lndex = (Ch No. x 5) + 30 TABLE l II TABLE 3. i I II I STATUS FLAG BITS Dial I-ock: Split: Cfarifier: A/Bvfo: Mem/vfo: Tx/Rx: Gen/Ham: II i 'I. ' 0 0 0 0 0 0 0 = = = = = = = OIî funlkd) oFF (snptx) OtF, A seÌecteat, vfo opiatn, receivins, cen Steps, 1 = ON (tocked) 1 = oN (sptir txlrx) 1=oN t =vfoBselected j = nenory operarion j = transmittins 1 = Ean Band Steps FREQUENCY DATA Frequency diqits appear in the data strean as binary-coded atecimal {BCD: hexadeclnal representation of decimaÌ digirs), sith leading zero_fil1 to the '100's of À{H2 digit, Bytes aÌ:e send in reverse order, as described earfier anal again in the followinq example. '01è:Àl4f ( EvAÀ4pLE ) Mttzt Lrr."q. Index lndex lndei< lndex 32- + 3) = 01h + 2) = 23t, + 1) = 45h t o) = 67}r TEST PROGRAM LISTING Followìng is a Iisting of a BASIC program developed on an Apple [I computer using a Yaesu FIF-654 CAT lnterface Unit, which tests a number of the CAT System firnctions in the FT-7s7GXII. The pro$aú has been intentionally simplified so that it might easily be converted for use on other compùters with other serial i/o systems and with other variations of BASIC. As such, it is usefirl as an application program by itself, but rather is intended to !!! provide some ideas for a simple approach to CAT programming, which should be combined with the users own concepts for useful applications. This program is not copyrighted. Anyone is free to use any part of the code for their own use. For use in commercial applications, acknowledgement of this manual as the source would be appreciated REy +{rr+r InlLidt izÈ sè..aI r/o porf of r+rrr* 6ùputè! Data Port addrèss (particùÌar to rrî 65la Port address chtp (425r usaRr in rlF 65la) for init. for 4300 batrd. no parity, I stop bit. FOR I = 1 TO 3 : PO(E CMDPORT.O : Po(E cl4DPoRî,64: ?onE cMDPoRÍr207: "(0)...Enter rr(e )...Rèàd rreqùèncy" statstr fron cét ne* Prèqùèncy, test foi waÌid ne{ Freq. ùrz)" {decinal ; rREo rF IREO < o.rso oR fREo > 29.99999 F R E Ai n l o p d i r s o f d e c i f r l .REO : aREO i 10000 : MEZ = rNT (|REQ / 100000) : IrxHz = rNT (IREO / r000t r , r H zr r 0 0 : I { d z = r N r ( F R È o/ 1 0 ) !req." : G O T Ot t o 'r{}rl d;9rls (r0 s Òf ksz) to lnteqer REM 100 s and 10 s of úEz and 100 s Òf kHz s(Ezir00 : REù lo's and I's of kriz = IREo - rNT(Hz+ 0.s) * r0: sz sz r1 P? F3 14 Ez*r0000 €nter keybóard = = = = rNr rNr rNr rNr (MHz (ùKrz lxnz (rz sèt / / / / 1èawe100 s & t0,s of r:2. DéciÌal atlgit 10J + 16 + úEz rNr r0) * 16 + ú(Iìz - rNr 10) + 16 + Krz rNr 10) * 16 + Ez rNr 1000 : Goro 100 : rnstructi@ anit Padèt* {ù'sz (Mruz (ruz (!z / / / / 10) r0) r0) r0) * * * * 10 10 r0 r0 send to for othèr cóllìmnds xcvr, ;***'* = set Mode. Pl = lsb 6,I0 IFCMND=2T]ìEN r F c ú N D= 3 r s m r N s r - 1 2 : P 1 = 2 : r N s T = 1 2 :P 1 = 3 : IFCÙND:5TSEN r N s T = 1 2 :P 1 = 5 : rFiaD.aTEN rF o{D = 9 TsN GOrO 300 GOSùB1000 . Gol! r00 : REù rnstrùclion = set Moder ?1 = cr-q REú rnstructión - set Modè, Pl = an lEd = set vfo a/8, Pr = vfo a - ser wfo a/8, P] = vfo È rnstruction : s€lèct atata for alf srars, Dèternine typè rmp for s neter 33 data and loop. 7 340 lNSr.14: send "Retufn Dè1av" connand ? 1 = 1 0 0 : G O s urB0 0 o : 7s bytes NEXT r : COTO lO0 !r'te : lri ; I "siqnal 75 bYtè statùs lroPorr) , i**i-' Prirt statls Read àno'h€r bvt€ rèad rèad I bl-te s-úète! data ****** REú rnst = read conmandr dtr ; Pnn( lroPorr) : REù REù update *++"** Trarscèiwèr as èhev Send RlM i+++** r N s l = r 6 : P ] !Rl\r rèlurns : : Porn loPoRT'P] check serial 20r0 rosraT = PEr< (CrlDrOÌTl : rNr (rosîar / 2) : 2 O r 0 R S T À T ]= r N r l R x R D t / 2 ) . R S a À r 2 = R \ R D Y/ 2 : REM io.p ixrcy flag (bir r) to bit 0 o.rd 1sèt) or Even lrèset) untrl it is set RECEIVER FRONT END PROTECTION If the receiver is found to have suddenly losl sensirlviry, i.spect the filament of the lamp ,l- af U r'ì. If t rs npFr. r"p (l l00i o try to determine the cause of the overvolrage; eg., was rhe antenna lefL connecied durlng an F,c.-r.t \ ) \ , c ) s ó d r ìè r - i n c you Ìast used the equipment? lo obtain replacement Lamp fuses, ask your local Yaesu deaìer for Yaesu part no. Q1000010, BQ0,11 22803Aj of substitule any 8V l00mA pÌlot lamp. Do not jumper across the lamp fus€ lerminals however, as this will defeat rhe protecLion The feceiver front end in FT-757GXIÌ includes surge suppressor and a lamp fuse to protect the sensitive receiver clrcultry ffom high voìtage pulses (ENlP) at the antenna terminal. Several thousands of voÌts can develop natu.ally when dry wind or elec.ricaL storms create an electrostatic charge on the an!enna eLements, a.d this is delivered to the antenna jack jf the antenna is connected to lhe transceiver. In such a case, the lamp fuse may burr out (even ii rhe transceive. is rurned off at the lìme). The onll' way to avoid this condilion is to disconnect the àntenna from rhe transceiver $,ìrenever the wealher is ìikeìy to create high voÌtàge on rhe a.tenna (the feedline should be connected to ground to allow lhe charge to dissipare). and could resuÌt in serious damage. S.c pictùrc bclo\r f.r the lo.ationof the lanr! fuse. LAMP FUSE (F 34 ) E : > T z F ì i ; 6 i 6 ó ó : '; - Ì . 6 2 = : E3 3 i : E ;F : i FEEEE -EFEEE ; l F = : F F F F r : F F J : = :? : e : a e = à î z IT,J z o É , t = > g E > E = = > I = - ' = e =q =: z; :z z z E t =! : * s F È a È È È E ; : :Í si ; É = i ! i - . z z z z z + z = = Ei EREEE E- ÈÉ5 É É ; ' eii 3 i : : t r " j ;= E i ! EFEEFEEE ;EE ' : ==3: ; : : À a t = ! > > > > > > > > ; ! J=. e + z z z z é r É : ; : Rs " ' :E ÈÈÈ{ i ; : 3* i 3 Í í € > E : E E : ) - -,zL IJJ F 3 36