o oo BY JOHN J. SCHULTZ·, W4FA

The Corsair sports some brand-new Ten- Tec equipment styling

H ave the boys at Tennessee Technologycome up with another winner in their new ear­satr transceiver? Well, only time will tell. How­ever . they certainly have come up with a veryinleresting transceiver .

To start with, the Corsair has a br ight, newstyling as compared to some former ten-teeproducts It is not that the basic color schemeused has changed much , but the dark -outplexiglass panel over the meter and digital f re­quency display, the placement and groupingof the contrors and switches. the changed trimscheme , etc., all indicate that Ten-Tee took ahard look at the packag ing of their new top-ot­the-line transceiver, The result is a very"smartly' designed unit that really can only beapp reciated by seeing it. It is also an amazing­ly Iiqht-weiqht and compact unit (14 Ibs. in a15 " x 14' x 5'package)

General CharacteristicsThe Corsair is a 100 watt output class trans­

ceiver designed for C.W., s.s.b., Any, andSSTV operation on all existing and proposedamateur bands. Detailed speci fications forthe unit are shown in Table I. As one glancesthrough the speci fications, one will note quitea few interesti ng features, some of which wi llbe covered in more detail later, For instance.on receive the rt. preampl ifier can beswitched in or out , there is 2.4 kHz 12-polecrystal-ladder s.s.b. fi lter ing. various optional

s.s.b. and cw. filters. passband luning, select­able a.q.c. 6-digi l freq uency readout, notchfilter, noise blanker with adjustable threshold.RIT, and a good dynamic-range specification.

On transmit. 85-100 watts of output powe rare available, full break-in ope ration is provid­ed on csv. with stoetone. the metering in-

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eludes forward PEP power and s.vcr., and thepowe r output can be varied over a wide range .Speech processing is not mentioned, but it isincluded. The 100% duty-cyc le specificationis quite interesting in that it is ach ieved withoutthe use of any cooling fan! The controls, indiocaters. and connections available cover jus!about any imaginable operating requirement.

CircuitThe basic block diagram of the Corsair is

shown in fig. 1. Basically it is a single conver­sion circuit using a 9 MHz i.f.. but with an aocr­uoner down/up frequency conversion to 6.3MHz to provide a passband tuning feature,

The PTO feeds a variable 5.0 to 5,5 MHzsigna l into the " Osc ./Mixer" board where thatsigna l is mixed with the output 01 a crystalosc illator so the signal going into the " AF Mix­er" board is correct to work with a 9 MHz U .For instance, for operation on 40 meters,7.0-75 MHz. the PTa output f requency istranslated to 16.0-16,5 MHz in the "Osc./Mix­er" block. In this manner, full 500 kHz cov­erage is obtained on the 1.8. 35.7.0, 10.0,14.0, 180, 21 .0. 24.5, and 28,0 to 30,0 MHzbands (the lat ter in lour 500 kHz ranges).Crystals are inc luded for the 10.0. 18.0, and24.5 MHz bands. and the Corsair is ready to goon those bands. A few bonus featu res are thatthe PTa range actually has about a 30-40 kHzoverrun on band edges so many MAAS fre-

"c/o CO Magazine

22 • CO • January1984

Although the Corsair has new styling. it fits in nicely with other Ten- Tec equipment in this stationsetup, (The Hercules solid-state linear is below it and the Model 229 tuner is to the right. )

Say You Saw It In CO

Say You Saw It In CO

..-Frequency Coverage 1.8-2,3.35--4,0, 7,0--7.5, 10.0--10.5. 14 0--14 5. 18.0--1 8 5. 2 1 0--2 1 5. 24 0--24 5.28,0-300 MHz trereeeoe (V FO provides approximately 40 kHz overrun 00 each band edge)V F.O. StabilIty· Less than t5 Hz change per F" averaged over a ' 0 " change I rom 70· to 110· F ettee 30mmutes 01wa ' rnuc>. Less than 10 HZ change Irom 105 to 125 v.a.c. line vollage when USIng a Ten-rec power--TUnIflg Rate: Vernier. 18 kHz per revoluhon,lyplcaLReadout 6 d'91t. 0,3· LED numerals ,Accuracy :!: 100 Hz.Seml-GonductorS 1 LSI,2O ic's. 94 neosrstces. 107 d iodes. 6LED readouls.PC Boards. 22 PC assemblies WIth p1ug.In cablesccosuoctco:Rig id aluminum chaSSIS, Dark pa inted aluminum front and rear panels, te ~ture<! IOP and ecucnSoap-up. steel ba ll.Po!Ner Required 12_14 vd c.• 850 rnA receive, 18,5 A max trensmrt.Dimensions HWD 5 Yo • x 15 ' x 14 · (13 x 38 x 36 cm), ba il rel raeladNet Weigh t 14 100, (6 ,4 kg),

ReceiVer

Sensitivity o25 ,.V lor 10 dB 5+ N/N , all bands 0.8,.V typical with r.I. ampnne- oil.Selectivity: t2·pole costauecoer liIlering 2.4 kHz bandWid th. 1.710 1 shape factor at 6/60dB. Three-positionsw itch seiecrs standard e.s.e. lilter, optiona l '-8 kHz s.s b. utter, 500 Hz c.w. filter, o r 250 Hz c w hiler.Notch Filler: Greater than 50 dB octcn tunable be tween 200 Hz and 3,5 kHz,CW soot With 750 Hz reference tone .f.F. Frequencies: 9 MHz and 6.3 MHz,Antenna Input: Low Impedance, unbelaocedAudioOutput 1 wa tt @ 8 ohms With less than 2% distortion. Bui lt-in spea ker .Spurious Responses: All below equivalent 10 dB 5 + NIN signal except 1.838 MHz (less than 15 dB S + NIN),21.300 MHz (less than 20 dB 5 - NIN). and 28,980 MHz (which ca n be el iminated by using low end of 29.0-29.5MHz band segment).Noise Blanker: Built-in. adjustab le blan king thresholdI.F. Reject ion: Greater than 60 ca.s.veter: Automatically switched on when receiving, Calibrated to 50 I'V at 59. ::l: 3 dB,Dynamic Range : 90 dB, typica l.Ottset Tuning: Dua l range, max, ::l: 4 kHz: min, ::l: 500 Hz, typical,

Tr.nsmitl"D.C Power Input Maximum 200 waue @ 14 v.d.c . c.w. and s.s b 100% dUly cycle for up to 20 minutes,RF. Power Output. 85- 100 wa tts. typica l,Outouf Impedance: 50 ohms, unba lancedMic rophone Input High Impedance. Accepts high· or low·impedance mic rophones wilh 5 mV output, Polariz·ing voltage ava ilable for electrets.TIR SWitching ' VOX or PIT on s.s.o. Inslant b reak·in or serrn-breae-m on c.w.C.W scercre: Internally generate<! AdJuslable tone and volume independent 01e.t. ga in control. ocetaies oo­Iy in c wo mode.S.S,B. ceeeraice: 9 MHz , 4-poIe crystalladdef tutet . Balanced rrocuietor.Ca mer Suppression' 60 dB IYPlca lUnwanted Sideband Suppression: 45 dB typical a t 1.5 kHz lone,socrsocsOutpul : Beller I han - 45 dB rerauve to lull ou tputMeIer: Forward power, eosecrcr cueren t. s w .r.. processing level. seecree ' -f)OSlt lOl'l SWllchc w.ousee 750 Hz, eutoenauc .A.L.G control : F,onl ·panel adjUSlal)le. 30 to 100 wall s outool, LED lIl(flcator.

Front-PllIII C,,"llKtioM Ind ConIflll

PST: OFFSET; AF·RF AMP; RF·PQWER, NOTCH; DRIVE; aeroswucn Main Tuning Knob; MODE : METERswitch; VOX GAIN , VOX DELAY ; PROCESS level; N.B.LEVEl; Ale threshold: OSKNQX SWitch; A.GG SWitch:XTAL SWitch: OFFSET SELECT SWitches (2): SPOT push-button: PHONES: MIC.

kI'·PI.... C",netliDns , nd C""rlll

EXT. TIR jilck: AUDIO IN jilCk. AUDIO OUT jack; AUX . 12 VDC jacks (2); KEY jack: PIT jilck . VFO IN jilCk, VFOOUT jack: ACCESSOfl IES sockel, llNEAR ecceer. GND lermlnal: EXT. SPKR jack: POWER socket. 50 OHMANTENNA connectOf (50-2391, RX ANTENNA jack. RX·TRX swilch.

Table 1- Corsair specifications.

23CIRClE 84 ON READER SERVICE CARD

one for gating and one tor noise detection, De­tection of tast-nse spike-type noise pulsescauses the gating circuitry essen tially to In­stantaneously interrupt the i.l. signal uow.Theinitial selectivity is provided by a stanoarda-pore 2.4 kHz s.s.b. filte r. If desired, this fillercan be replaced by an ocnoner a-pore crysta lfilter.

The signa l is ned routed to a passband ron.ing board as shown in fig , 3. The feature Isneatly executed, 0 3 is the local oscillator, andits nomina l 15.3 MHz crystal-cont rolled tre­ouencv can be shilled plus or rmnu- a lew kHzby controlling 017. an MV209 varect or diode.The incoming 9 MHz signal is translated to 6.3MHz. goes through one of the crys tal filterblocks (fabeled 2.4, 1.8, ,5. and ,25). and thenis retranslated to 9 MHz in the output stage0 2. By varying the frequency ol lhe 15.3 MHzoscutator, the passband 01 the crystal lilter onthe board is moved across that 01 the preced­ing 2,4 kHz l ilter. The standard 2.4 kHz s.s.e.

quencies are covered, the 1.8 MHz band ex­tends to 2.3 MHz to cover par t ot the Marineband, and the 10 MHz band includes, ofcourse, WWV.

In the receive mode. incoming signals arerouted through the Jowpass filter assembly re­curreo for the PA stage (a uve-core filter oneach band), via a PIN diode circuit for inputsignal switching to Ihe bandpass filter boardand then toa 2N3866 r.t. amplif ier stage. Thisstage is snown in more deta il in fig 2. II is inter­esting in met u is completely broadband withno tuning required. In teet. the only " tuning"assocratec with the Corsair is the main tun ing.After amplifica tion, the Signal is routed 10 aoocme-beiencec diode Quad mixer on thesame board for translat ion 10 the 9 MHz t.t .The board also con tains a tow.nose LI.pream­pli fier. The following oorse-btareer stage is in·serted in the U . path ahead ot any high·selec·tivity c rystal lrtter stages. The rorse-blankerstage splits the incoming signa l into two pe tns,

TUBES, SEMICONOUCTORS, IC'S0I00ES AT SUPER LOW PRICES

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OA2 _. . . . .. .. $2.751-400Z . . . . 115.00:J.5OOl 90.004CX2SOBl7203 53.004CX1 00llAl8168 .. 430.004PR6OCJ8252W, . ,295.004X1SOAl1034 , ... .. 58.00SAR4 . . .. . . _. . 4.13SC22 . . . , .. , . 185.00SR4GB . . . , .. . 3.858,,1(,5 , . . , U 6BALS , 2.936A05 . . , _2.85BCAT . . . 5.81SDJa _ , 2.758JGBA . . , 8.536J56C , 8.056KD6 , . . . 6.908l6GC . . , _ 5.256KV8A . , 8.026lF6 . 1.111BLOB 6.838MJ6 . . , . 7.2812ATT _ _2.9312AU7 . _2.6312AX1A . . 2.64572etTl60L . , .. 49.50105A . 10.00811A . , . . . 13.50813 , . . . <1.0.00829B .. 40.00832A , . . 33.00833'" 145.00866A . 9.50812,\ _ , . 24.00M·2057 . , ,1 5,005670 , , 4.40SS&t _ .. , _33.005687 , . _4.005751 , . . 4.005814A .. , . 3.705379 .. . _ , 5.755894 , . . . , . 65.006005 5.2581488 , .. 7.SO8360 _ 6.50852M 75.0085501t .. , . 1.5088838 9.001380 .. , ... , . 12.251558 , . . 1.001591A . .. 4.101863 , .. , , 3.1 58012 95.008-411 . , .. ... , , ,6.616314 . , .. , .. , 195.006315 . .. 210 .00631113CXl500A1 . 415 .008906 .... .. .. 12.9589SO , . 11.50MRF·453 , . . , , . . 111.95MRF.4S41A . . .. , . 19,95MRF·4551A . . , . 19.952N6OU . . 15.00

za§

CIRCLE 12 ON READER SERVICE CARD

filter on the passband tuni ng board has 8poles, and since it operates in series with thepreceding, standard a-core filter, the overallresu lt is 12 po les of Lt. filter ing, The optional f il­ters which can be placed on the passband tun­ing board are all diode switched and are pre­ceded by resis tor attenuator pads for overaugain equalization when switching between fil­ters. (The ,25 kHz filter does not have a pad,since its loss would be the highest that the oth ­ers have to be equalized to matc h.}

Afte r the passband tun ing stage, the re­ceived signal goes through some U. amplif ierstages and on to a dual-gate MOSFET productdetec tor stage, The demodu lated signal isthen routed through a notch filter. The notchfilter is tunable from 200 to 3500 Hz wi th a50-60 dB notch depth . This is a particularl ywide range for such a circuit. and details of itare shown in fig, 4. Final audio amplification isvia a LM383 IC to produce about 1watt output

with less than 2% distortion 10 a built-in speak­er. Ag co, which ts ot the time delay or "hang "type, is audio derived, so itlollows the settingof the audio notch control. The same board.fig, 4, also contains the stdetone oscillatorwith adjustable pitch and volume and a spot ­ting oscillator. The latter is set at 750 kHz, thesame as the i.f. offset on c. ve ., and can be acti­vated by a front-panel pushbutton. Its tone canbe beat aga inst that of a desired c.w. signal forexact zero beat.

In the transmit mode, one can visualize thecircuitry as working partially backwards. Themicrophone signal is amplified and then pro­ceeds to the VOX and a.t . speech processorci rcuitry as shown in fig ,S. The a.r.processoris interesting in that it consists of a peak clip­per and compresso r. 011 and 01 2 performthe clipping function, while t ransistor 0 3 is theshunt element fo r compression. The process'ing level can be set by a fron t-panel contro l.

24 • CO • January 1984 Say You Saw l t In Ca

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IIII ~.-IIIIIIIIIII @LFig. 2- The first active device in the "tront.era" of the Corsair is the t.t. amplifier stage Q2, which is a broadband amplifier. After this stage thereceived signal goes through a double-balanced mixer and " exits " via 03. another Jow-noise amplifier. Diode switching provides for using cir­

cuitry on the r. f. mixer board for the receive and transmit signal pathS.

."

pretty bland description 01 any conventional,soqre-converslon 9 MHz transceiver. How­ever , it was meant just to set the groundwor kso one can visualize the baste makeup of theCorsair. So, what makes the Corsair different?In one sentence it cou ld be expressed as "in­novative and honest execution of a basicallyproven transceiver design concept using ex-

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D ~ ~L JFig, 3- Th e passband tuning system is neatly conta ined'on one circurfboard, except, of course,for the front-panel po tentiometer which controls varactor diode 017 and (he switches used to

select diffe rent filters.

ConstructionThe forego ing, f rankly, may sound like a

transistor switches for controll ing volt agesthat switch the transistor between the rec eiveand transmit modes. Among other things, itprovides for a slowlfast break-in feature onc ,w,

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Fig. 5 also shows the VOX circuitry. wh ich hasfront-panel controls for ga in and delay ,

After the circui try of fig. 5, the a.t . signal isfed to a balanced modulator and a c.s.b. signalis generated. The d.s.b signal goes throughthe standard 2.4 kHz s.s.o. filter and on to the"RF Mixer " block, where It is translated to thefinal output f requency , The signal is then am­plif ied in various stages until it reaches a pairof MRF·458 transistors which operate in apush-puf arrangement at 200 watts o.c. inputon al l bands. The PA stage is completelybroadband and touowec by a lowpass filter as­sembly and an s.w.r. detection block. TheIrcnt.panet meter automatica lly switches be­tween be ing an "5" meter on receive and amulti-function meter on transmit. The s.w.r.reading lunction is unique in that there is none01 the usuallorward "set" adjustment neces­sary. Also, the forward power meter reading isof the peak-reading type, so it indicates PEP.

The S.W.r. bridge circuitry also supplies ana.l.c . feedback vo ltage and a control voltagewhich is used to drive an " ALC" LED which in­dicates relative out put power .

Circu itry that is common to both the receiveand t ransmit functions includes the frequencyreadout and control c ircuitry. The f requencyreadout circuitry basically revolves around anLSI IC, the MOSTEK type MK50398N, It ac­complishes all of the counting, latching, mul­tiplexing, output decoding, and dr iving func­tions on a single ch ip. The counter basicallyreads the "Osc./Mix" board output freq uency,but it is fed preset information to convert itsoutput to the ac tual transmi tted or receivedfrequency. It also follows and indicates anyfrequency offset set by the' 'Offset" (RID con­trol in the receive mode. The actual readout ison large O.3 inch LED displays with the six·digitdisplay having five red readouts and onegreen readout for hundreds of Hert z. The con­trol ci rcuitry basica lly encompasses various

26 • CO • January 1984 Say You Saw It In CO

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ceuent Quality, ccoservauveiy rated coree­nents. ' There are not a lOt of " bells arc wtus­l ies" as found on some transceivers (al thoughevery needed feature is cresenn. Overall, onereceives the impression that the Corsair wasdesigned by dedicated radio amateurs whoactually use the equipment themsel ves.

Two photographs show the Corsair with itstop and bottom covers removed, As one cansee, ten-tee has taken the design approachof splitting the circuit ry among a fairly largenumber of PC boards. In fact, there are some22 PC boards. This type of approach requiresa good amount of interconnection wir ing,but itkeeps various signal circuits isolated, and coecoes not have the prob lem 0 1 spikes andspurious signals running around a very largePC board. It is probably one reason why theCorsair has such a cieeo-sounding signal bothin the receive and tranarmt modes.

One can see from Ihe photographs that thePC boards are very neatly arranged, and a lotof care has been given to shielding of individ ·ual sections , For instance, the receive r I. am­plifier assembly is shown in the center of thephotograph with the bottom cover removed,the shielded PTO assembly is below it. the out,put tow-pass filters are 10 me left back in theirenclosure, the L I, power stages are in a corn­pletely shielded enclosure with heal sinkmounted on the rear panel of the transceiver,etc. One can also see Irom the photog raph ofthe top the space which is provided on the top­right PC board tor the installation of the ccton­all .8 kHz s.s.n filter and the 500 Hz or 250 Hzc.w. filters. The bandswitch ing assembly (pho­tograph of the boltom) looks rather imposingwith all its sections, but it works Quite smooth­Iy. In fact. it feels like a single wafer switch

Say You Saw It In CO

when one acwauv uses it Everyth ing IS

switched direct ly by the bandswitcn. Thereare no diode switChing schemes used as far asthe main r.t c ircui ts are concerned. The onlysignificant diode r.t. switching that is done is inthe circui try which selects the optional s.s.b.or c.w, filters.

MeasurementsThe " specs" measured on the Corsair are

tabulated in Table I. It doesn't take too muchperusal to see thai it easily meets its ecver­usee Claims, The power output varies over anextremely narrow range from98 to 99 walls asone goes from 10 down to 160 meters. Irs in­teresting to note once again Ihat allhough theCorsair PA has the usual thermal and otherprotective ci rcui try, it doesn't have an internalIan and it doesn't need one for extended s.s.e.or c .w. operation. Full power is available onRTTY and SSTV tor 20 minutes key down, at­Ihough Ten-Tee does recommend an externalIan if these modes are to be used continuous'ly, The third-order IMO products remain at arespectable - 32 dB or better at lull poweroutput Sideband rejection and carrier suoore­sian measured a respec table - 43 to - 54 dB.Thec.w,keying wevesnece is excellently "reu­ored" with 3 ms rise and lall times.

On the receive side, the s.s.b. sensmvttyvaries from about 0 15".V on 10 meters to e.a".V on 160 meters lor a 10 dB StNIN ratio withthe r.r. amplilier in the circuit. The dynamicrange measured OUI at a good godB on 40 me­ters (s.s.b. bandwidth). The tturc-croer mter­cept pomt measured a very good + 7 dBM, in·cr easing almost 10 dB with r.f. amp lif ierswitched out. Slight receive " birdies" were

tound at 6.999 and 18,165 kHz plus an 59 +one at 28,980 kHz. The latter is c learly recoc­nized by Ten-Tee in the Corsair manual. In re­ality, it is not significant. since il one had to usethat frequency, the transceiver could be seton 29.0-29,5 MHz and then the over run tuningcould be used below 29.0 MHz. In that case,the "birdie" completely disappears.

OperationOperat ing the Corsair is easy, and, 01

course, that is where all the fun comes in asone ecorectares the way the Corsair featuresand con trols are arranged , The main tuningknob covers about 18- 20 kHz per revolut ion.The "teet" IS light and easy and probably willbe most apprec iated by the contest operatorwho operates long periods at a time. I wouldprefer 10 see a deeper finger well on the knobor a raised finger spinner, but that is strictly apersonal preference. The digital readout isabsolutely rucker-t ree and extreme ly pleasantcompared to some 0 1 the miniature readoutsfound in other equipment.

The "5" meter is an honest one. It requires451'V on 20 meters to get it to read 59. As onetunes through the bands, signals seem tocome out of an almost Quiel noise back­ground. ThiS sort of feature is hard to cnar­actenze even by noise base and other meas­urements. One finds it in very few pieces ofequ ipment. and it really con tribu tes to fatigue­free operating lor the type of operator whOooeso't mind spending hours searching for aselect OX stauoo. The Corsair performed reomarkably well on the low end of 40 meters inthe European area , where atleast 50% of the"trent-enos" of most transc eiver s completely

January1984 • CO • 27

A 100If inside witn the top cover removed. All me crys/at banks to memiddle left are rne optional s.s.b.lc.w. filters

A took inside me Corsair with the bottom cover removed. The band­switch is on the letl and can be seen extending from the front panel to

almost the back panel,•

Fig. 5~ reo- Jec has come up with some interesting circuitry for the stan dard a.f.·type speech processor in the Corsair. The circuitry mainlycenters around U3A U3B. 03, and dIodes 011 and 0 12. The diodes per form a clipping function white 03 per forms a shunting tunction for

speech compression.

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28 • CO • January 1984 Say You Saw It In CO

Table 11- Corsair lest measurement summary.

mance lor a purely a.t. type of speech oro­cessor. In tact , most stations who were askedpreterred the audio with Ine proc essor in use!However, as is the case with almost any typeprocessor, one must avoid the temptation tooverdo the processing. The Corsair mccrpor.ates a very handy a.tc. LED peak indicator. Ifone adjusts the processor so the a.tc. LEDjust tights on voice peaks. effective speechprocessing will be assured.

CIRCLE 26 O N REAOER S ERVICE CA RO

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Band Sepsnlvlty Power Out{-"VI (wansl

160 3 9880 .3 9940 .3 9830 .24 9820 .14 9818 .14 9915 .15 9912 15 99lOA .14 99lOB .14 98

S.SB. sideband fejechofl at I kHz - 45 dBCaHie. Suppression - 54 dBI.F. ReJecli(Jn: - 60 dB averageDynamic Range (40 M): 90 dBThtrd-Oroer lntercept: + 7 dBmrnno-oeoer IMD: _ 30 dB or eeuerC.W. Waveshape Rlselfall Times: 3ms

AccessoriesBesides the optional i.l. raters. the main ac­

cessories available lor the Corsair are theModel 260 Power Supply and the MOdel 263Remote V.F.O.

The power supply is designed to deliver aregulated 13.5 votts at 18 amperes nominal or20 amperes maximum. The circuitry consists01 a bridge rectifier. 26.000 mF olfil lering, andtwo paralleled 2N5301 pass transistors. Thepass transistors are controlled by an IC regu­lator and driver t ransistor . Regulation is bette rthan 1% from no load to lull load An SCR"Crow-oar" circuit is incorporated whichshorts the output il it should go over 16 volts.Another SCR is used in a latching ci rcuit whichturns off the ci rcuitry when the output currentdrawn exceeds a preset value of 20 amperes.The latter circui try really operates Quickly ilone should try to tune up too Quickly such thatthe e.w.r. to the Corsair is great enough to ex­ceed 20 amperes being drawn from the sup.ply. It will trip out almost instantly. It otters ex­cellent protection lor the finals in the Corsairand quickly disciplines one to tune up orcoer­ly. Reselling the circuit is easily done by rock­ing the front panel power switch back andlorth. The power supply also contains an 8ohm ceramic magnet speaker. There is onlyone main onpnure.but extra rear-panel con­nectors are provided, so one atso res avail­able two regulated 12 v.c.c.outputs lor smallaccessory items.

The 263 remote v 1.0 , covers aU the sametreouency ranges as the Corsair. It consistsessentially of the same PTO subassembly asused in the Corsair, plus switching c ircu its, ac rystal oscillator, and addi tional ouuerrerrcu­ner stages. Four crystal positions are c rovrc­ed which one can use in any desired combine­tion within or among rne amateur h.l. bands. IIone does use crystal-controlled operation. theout-ot-bano limi ts that ca n be achieved aresomewhat greater than when '1.1.0. control isused. For instance. one can go up to 4.10 MHzon 80 meters and down 10 6.9 MHz on 40 rne-

rail apart in the face of broadcast ORM. The"hang" a.a.c. system is very effective, with anapparent discharge time of about 1 second ons.s.b.

The optional crystal utters. the standardnotch utter. and bandpass tuning provide lorabout any reception problem one will en­counter. The selection of optional tnters ishandily done by a separate toggle switch, withthe selectivity increasing as one goes from the3·2-1 switch secuence. It is handier to usethan arrangements which couple filler selec­tion With a mode selector switch. The fact thatthe onset tuning (RIT) provides lor selectableshifts of either ± 500 Hz or ± 4 kHz makesthis type 01 control ideally tailored lor c .w. ors.s.b . operation. Both the optional s.sb. andc.w. utters are highly recommended, but theoptional 1.8 kHz s.s.b. filter deserves specialmention for s.s.b. operators. It really hassharp skir ts down to the - 100 dB point. Theuse of the filte r can easily make the differencebetween a solidOSO and a so-soosc on s.s.b.especially during weekend CRM conditions.

The a.t. gain control has a pull·switch lea'tcre to insert or remove the r.f. amplil ier Iromthe receive r.l . line. With a beam and under elt·tremely strong signal conditions. one mightlind a use lor it. Normally, it probably will neverbe used. The noise blanker was not given areally thorough check, although it seemed tolunction extremely well by occasional auto>mobile ORN atthe test OTH. It seemed to helpthe situation somewhat when the Russian" woodpecker" would scan through one 01 theh.f. bands, the adjustable threshold coerrorbeing very useful to tailor its response.

On the transmit side, one should first men­lion the easy tune-up procedure incorporatedin the Corsair. On transmit, the panel metercan be set to automatically tuncuon as ans.w.r. meter and, as mentioned, there is no" set" control! The meter reads s.w.r. directlywithout any arfjustment. To tune-up, oneplaces the Mode swi tch in the lock position andadvances the Drivecontrol lor increasing pow­er output as one perhaps adjusts an antennatuner for minimum S.W.r. reading on the panelmeter. That's all there is to it.

When operating s.s.b., the mode switch isreturned to a sideband position (normal or reoverse) and the drive control readjusted so theALe LED just lights on voice peaks.On c.w.. nofurther readjustment of the drive control is reoQuired, but one can choose between last andslow break-in operation by means 01 the panelswitch marked aSK/Fast or aSK/ Slow , Instantbreak-in is provided in the aSK/ Fasl position.That is, if one is transmilling a word such asTEST at 20 w.p.m., one can easily hear abreak-m between sending individual letters. Ifone has the SWitch set in the aSK/ Slow post­tiOn, break-in's can be heard between thepause between words. In any case, c .w. coer­ation is pure pleasure. soetcoe VOlume andpitch are easily adjusted by thumb-wheel con:'trois accessed via an opening in the bottomcover. On s.s.e.. consistent reports were reoceived ot good, clear modulation (a ten-teeelectret- type microphone was used). In fact.several sta tions rated the audio as "superb,"commenting that it was "sharp" but with justenough bass to make it pleasant to copy.

Many tests were made to evaluate theeffectiveness of the Corsair's speech proces­sor. The average result was that the Corsair'sprocessor cou ld inc rease the apparent reoceiveo signal strength by 5-6 dB (about onehonest "S" unit) withOut any noticeable audiodistortion. That is rather remarkable perter.

29

then goes on todetailed oPerating instructionsand hnally to alignment and service. Deta ileddiagrams. theory at operation. and alignmentinstruct ions are pr ovided for every PC boardDetai led voltage cnece-comt charts are in·c1Uded, as we ll as a generous use of ceotc­graphs to show parts location. The manual islabeled an "Owner's Manual: ' and It'S nice toknow Ten-Tee st lillhinks amateur equipment" owners" are deserving 01 having completetechnical deta ils on their equ ipment . The man­uals lor the accessory items are, 01 course.smaller , but they cover just as much respec­uve ceteu.

All 0' me equipment comes wilh the neces­sary Interconnecting cables, so il one our.chases the Ten-Tee line, it a ll s imply intercon.nects in a lew minutes' time. However, eachpiece of equipment also comes with extra ac­cessory plugs (except 'or the tota lly stanoarcones such as the V. inch headphone Iype), soone can make up any necessary mter conoect­109 cable 10f use With equipment 0' anothermanufacturer.

The Customer Service Dept . a t Ten-Feesimply has to be rated as superb. and I'm nolone 10 give ou t such acclaim IIghlly. The cor­sal ' received got banged around a bit dUringInitial Parce l Post shipment to an oversea's.milita ry APO add ress. The receive tuncro noeo't work orcoerw upon receipt, and the unitwas Shipped back for repair . Ten-Tec replaceda oerecnve crvster on ue PBT board, and theCorsair wa s received and in coeretco againtwo weeks la ter. Considering tnat lhe routingwas Tennessee to New York 10 Germany toNew York to Tennessee over a hOliday seasonand Via a complicated U,S. Posta l ServicelU ,S, Army Post Office system, it would appearthat the crew at ten-tee must have servicedthe transceiver almost instantly. The relurnedCor sair even included a check to cover mymailing costs in returning the unit to them.

All in all, it is obvious Ihat the Corsair is thecu lmination of many years of transceiver oe­sign and operating experience by the radioamateurs at Ten-Tee. Any amateur who in­vest s in the Corsair and perhaps some a! theaccessory items should be more than wen-sat ­isfied by his purchase for years to come. WI

ters. This may be an advantage for some spe­cialized uses such as MARS cceranon. Orner­wise. tr e operation 01 the 263 is bas ica lly thesame as any second v.t.o.. except that Ten·tee has incorporated a lew extra switchingpossibilities ,

As a second v.t.o.. the 263 can be used asJust a temporary memory for a frequency 01 in­te res t. as an actual ccerenrq v.t.o. for scm­frequency operation. or as the main controlv.t.o. for the Corsair. The mode selectorswitch allows the Corsair V.l.O, to controltransmurrecetve frequencies, me remotev.t.o. to control both frequencies. or the tre.ocencres to be split between the v.t.0. 's. A "re­verse" pushbutton temporarily exctences tilev.t.o. 's when they are set 'or split operation soone can quickly check tha t one is not acciden­tally set up to transmit on top o! an out-ot-bandOXstation. The mode switching also providesfor both v.t.o.ts 10 be used on receive so onecan ze ro beat them if desired.

All in all, the 263 proved 10be just as stableas the basic Cor sair v.t.o. and a very conve­nient operating accessory Full break-in coer­auco is maintained using it. As regards the op­nonet U . fil lers. Ihe useturness of Ihe 1.8 kHzfilter for s.s.b. ccereuco was already men­tio ned. However. I lorgot to mention the co­tional 8-pole s.s. b. nner (Model 220). wh ichca n be used to replace the first. standarde-cole liller in the i.l. chain. If coe's pocket­book does not allow lor too much leeway. theModel 220 filte r probably stloulcl be con sid­ered as a pr imary purchase, since it works inconjunction with the passband tuning, and itsusewitl improve both c. w. and s.s.e.selectivityunlil such time as one mighl consider an in­vestment in scecrnc ccucoers.s.o.rc.w. fi lters,

Fina lly, a word about teo-tee's manualsand customer service The manua ls are not onglossy paper stock. but they do an excellentteo. For ins tance, the Corsair manual writerrightly anticipated that mosl new ownerswould not first want a dissertation on trens­ceiver theory, but rather would wa nt to gettheir gear into operalion. tneretcre. the man­ual starts out with some condensed operatinginstructions (just enough to get the unit prop­erly and safely hooked up and operatinq). It

The rear panel is clean and functional, There is no cooling fan, and none is needed for normalc.w.ls.s.b. operation. Even etter extended operating periods, Ihe heatsink never gOI more Ihan

slightly warm to the louch

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• General Communicallon• Industry• Marine VHF• Scanners• Amateur BandS• CB Standard• CBSpeciaI

• Mocroo<ocesso<Call or Write

JAN CRYSTALSP.O. So. 06017FL~ Fl 33!J06-1017..... PtMH_ 1.1)1 " - 2391

CIRCLE 2~ ON READER SERVICE CARD

CIRCLE 60 ON READER SERVICE CARD

CIRCLE 10 ON READER SERVICE CARD• • • • • • • • • • •

• • • • • • • • • • •Limited space?

Here's the antenna for you.• Covers all ham bands (80 thru 10). •

Fully assembled and guaranteed .

$45 00 Postpaid USA• Send for f,ee brochu,e

Rudy Plak. W6TIK• PO Boll 966 San Marccn. CA 92069 •

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30 • CQ • January 1984 Say You Saw It In CQ