Kenwood TS-950S Service Manual

Also see for TS-950S Digital: Instruction manual Instruction manual Instruction manual Instruction manual Service manual

Lo-YoUS/OVCIRCUIT DESCRIPTIONReceiver and transmitter audio is routed throughthe Digital Signal Processing Unit when it is installed.This unit supplies either a simple 455 kHz carrier (FMMode) or amodulated 455 kHz IF frequency in all othermodes. Figure 1 shows the transmit and receivefrequency configuration .Frequency ConfigurationThe TS-950 utilizes quadruple conversion for SSB,CW, AM, and FSK modes and triple conversion for FMmode. The transmitter utilizes double conversion inCW and FM modes and triple conversion in SSB, AM,and FSK modes.ant10K ~SOMHE 1% 1x 1%MIX T3OSMH2 — MIx2 Oia { 2™« ose wieHf +-O%- O-~ nealae Tsse.Fsx.am.cw tse sse | [ema.e3MHr 455KHr tear | 1xA 17 MixaTIN “|MARX MARX MoRX pay MARX NOTCHwixt —73.05muz | Mie mixs | FSK.AM vie “ookMainn ! mseet - VeM A5SKH2 o:scesML MLS MLa {MCARM.LOT M03 MLce M,CAR aFsKcow PITCH) ( )Qe) ©73.06 ~ 103,05MMz 64.22MHr 9,.285MH2 SS5KRr m Mantis: 1egxin?SPACE!2. 294K H2USB: + 1.5K USB: + 1. 5KH2 (DSP ON? CHW:= 0.7KH:US8:- 15KHE LS8:~ 1.SKHz (OSP ON) CWT!=O.IKH2Cww:+0,TKHE (08P ON) CWNT [+ 0.8KH2 ¢WW: + 0,7KHE FSKL+2.2KHEFSKI-70HR ony és AMRF MR: #352$u8 SK sO.HELOSP ON M14 40,055 MHz MIx2 10.695MHz $-DE™= \_A181 18L2 1s¢Exe 8.402 S.can~40.065~ 70.055MH? 50,75Mnz 10.695MHUSBAAMT RACERHE USB.CW, AMT:~ SKHE fii : MAIN band local freq 1LSB Pat SKHE use ANCHE fmi2 : MAIN band local freq 27 140.7KH FsK 1+2,2KHr :enti fmi3 : MAIN band local freq 3Fig. 1 Transmit and receive frequency configuration+ Main frequency configurationThe equation shown below holds true when thereceiver is zero beat.fIN = fMi1 = fML2 — fML3 + fML4 + fMC oo... (1)Since all these frequencies are generated by thePLL circuit (as shown in Figure 2), the receiver fre-quency is determined only by the reference fsTD andthe PLL divide ratio. Therefore, the stability/accuracyof the reference frequency determines the overall fre-quency stability/accuracy of this transceiver. The sta-bility/accuracy of the reference crystal oscillator usedin the TS-950S is 10 PPM (-10 to +50°C}). The fre-quency stability is 0.5 PPM (-10 to +50°C) for the TS-950SD or when the optional temperature compen-sated crystal oscillator (TCXO), SO-1 or SO-2, is usedwith the TS-950S. When an external reference isused, the stability/accuracy of the transceiver will bedetermined by that external standard.The TS-950 local oscillator and the CAR PLL circuitsare independent of each other. However, they can befis: MAIN band local freq 4L fmc : MAIN band CAR freqoperatedin amannerthatissimilartoa“cancel loop”configurationbychangingtheCARandlocaloscillatorPLLdatasimultaneouslywith themicroprocessor.Thisfunction allowschangesinthefmc andfMt1lineswhenthemodechanges, andalsoallowsthebandwidthoftheVBTand slope tunetobevaried(fmML4andfML3,fML3 andfML1).Whenusedasatransmitter,thefrequencyisdeter-minedbythereferencefrequency(fstTD)anddivideratio.Thedisplayfrequenciesinthe variousmodesarelistedinTable1. (intheFSK mode,theTS-950,unliketheTS-940,displays themarktransmitter frequency.)Thepitch of theincomingreceivesignalintheCWmodecanbe adjustedto suittheoperators preferencewithout changingthecenterfrequencyof thetrans-ceiver variableCWpitchsystem.Changesinthereceivingpitcharedirectly relatedtothetransmitterCWsidetone.This resultsin aeasyzero beat proce-durefortheCWoperator.