AVCOM COM 3-R COMTECH55O QUALITYYOU ArcOMCANDEPENDON $atelhte@:eiue6 ModulorCircuitry High Performonce lmogeReject O TheCOM-3 Downconverter Scan-Tune Up to Six Audio Subcarriers VersatileFront Panel Controls Positive Handsome.Hand-etched. Anodized Front Pdnel Detented LNA Powervia Coax or RearPanel Connector ChonnelSelector AIrcOM a ConservativeDesign a ExceptionalReliability a Quality Construction a Technological Superiority COM-3Rcomplete with REMOTECONTROL UNIT / Everythingyou need for your complete SatelliteEarth Station dr Seeyour ArcOti dealeror contactus. AVCOM OFVIRGI NIA I NCORPORATED DealerInquiries Invited 500 ResearchRoad. Richmond.VA 23235.804/79+2500 T2-5/81 tcooPslsArELLrrE DrcEsr of readerswho wantto staycurrent, know enough about the technologyto be a step ahead of their customers...butno more than that. I vlew thlg wlth mlxed emotlons. We need a strong dealer/distributorbase certainly.We also need a strong hands-ontechnical base made up of peoplewho liketo tinker, experiment,and attemptto make equipmentwork better. OliverSwan, who'invented'the low-cost TVRO spherical (for cooP's example)developed this now-importanttechnology because he hada curiousmind. No amountof corporatefunding or COMMENTON researchcould have created the low-costspherical for us as an industry.Oliver shared willingly,perhaps to his own TECHNOLOGY financialloss. But the industryis much strongertoday be- causeof histinkering and willingness to share.Looking at the oppositeviewpoint weseethe COMSAT Torus antenna being licensedby COMSATLabs and the commercialversions of samegoing for nearly$30,000 a whack.Had Oliverhad the COMSATapproachto keepinghistechnologyto himself we'd still be scroungingaround for militaryor Bellsurplus dishes for'cheap'installations. THE PRICEWE PAY... We need a tinker/hands-on/cutand try mediumto share The first issue of CSD was back in October 1979. That ideas,experiences, and the basicsol an explodingindustry. doesn'tseem that long ago,but whenyou measurethe time CSD offersthe mediumbut boxed in as we are with a first span by the numberof new satelliterelated business ven- classmail delivery commitment (something I am unwillingto tures launched in the interim,or the number of people changesince second class is very ineff icient) and the needto involvedin this activity,it is a significantperiod of time. keepCSD small enough that it can be'closedup'one week CSDwas to be a "comprehensivenewsletter". That's why we and mailedthe next,it is notthe rightvehicle to get us where started off mailingit via flrst clase mail,to insure timely we need to be. The satellite industry also needs more deliveryof the importantfacts and informationeach issue exposure;a betteropportunity for newblood to find out what wouldcontain. In thosedays we placed67 centspostage on we are doing and get involved.lt also needsmore room to eachissue inside the USAand for thosegoing to the furthest shareand exchangeideas. mail points(such as New Guinea)around $3.00.The first It appearswe need a gecond publlcatlon; one designed issuehad around ten advertisersand we beganwith just over fromthe beginningto coverin greatdepth the subjectareas 500 subscribers.The recentApril issue contained 52 pages; CSDcannot cover. One designed to be infront of newpeople plus the cover.Early issues contained 32 pages.The recent on newsstandsacross the country.One designedto be less April issue also contained50 advertisementsand it cost costlyto produce(even though larger in size)and therefore o "sample". $1.20to mail to NorthAmerican readers; up to $7.00 (!!!)to less costlyto purchaseor New Guineatype points. I'vebeen jotting down my own ideason this subjectin a Advertisingrates went up in Aprilby about20%. I did this specialnotebook for severalmonths. And I havediscussed anticipatingthe recentpostal increase; reluctant as I was to thisat lengthwith a fewpeople in this industry who havegood increasethe annualsubscription rate of $50 US($T5foreign), insightto what is happeningtoday and is likelyto happen decidingthat by raisingthe ratesfor advertisingwe could tomorrow.Out of all of thishas come a planand a conceptfor coverthe 20% postalincrease. a new magazine.But I am not readyto announceit quiteyet Nowsome might suspect that with 50 advertisementsCSD WhatI am readyto do is to talkabout it, quietly and seriously, is rakingin the cash.I wish that werethe case.In the same with thosewho mighthave some contributions to makein the periodsince October 1 979 baslc printingcosts have gone up formof publish-ablematerial. I don'tintend to writethis new by 39%. With 52 pages versus 32 pages,a 20% postal publicationmyself each month,as I now largelydo for CSD. increase,increased basic costs for printing,mailing enve- To insurethat new ideashave a forumfor presentation,we lopesand labor...weare endingup with sparemoney to plow want to encouragelively reader/industry participation from back Into editorialresearch and costs almost to the dollaras the outset.lf we don'tstart sharing again we aregoing to end we did with the first issuel up like COMSATand others who mistakenlybelieve that At the sametime the'tone'of CSD haschanged to reflect technologyonly advances under their own roofand the work the tremendousincrease in dealer/distributor/newproduct of othersis seldomif everformally acknowledged. activity.Most presentCSD readersare notthat Interested in Let mo hearfrom you. Confidentially of course.Even if you GaAs-FETamplifier designs but they are interestedin what feelyou cannotcontribute to sucha forum,your thoughtson worksgood (and does not work good), and, the slmple basics whatyou would like to seeincluded in a newpublication such of the technology.In otherwords, we havea highpercentage as this are importantto me. COOP'SSATELLITEDICEST T3-5/81 Lv trusted4300; on mostchannels. But not on all channels. Final in-briefanalysis: The 4OOOworks betterthan the 4300 we comparedit to andthe picturequality that one mightobjectto with PLL type demodulatorsis all blrt gone. But - you may haveto tweekon the appropriate(manual identif ied) controls to get peakperformance of the unit aftertaking it out of the A BRIEF box. ICM also has a new accessory box whlch we found of conslderableuse.lt is theirAudio Subcarrier Tuneable De UPDATEON modulator.By plugginginto the subcarrieroutput jack on the 40OO(or wiring to the subcarriersection inside another RECEIVERS receiver,after the highpass f ilterthat separates the 5.4MHz up regionfor audio detection)and connectingan audio systemto the ICMunit you have one knob tuning through the full subcarrierband. Some of the newerreceivers have this built in but for older receiversyou were kind of on your own puttingit altogether.This is a highquality piece of gear(and not inexpensive;around $190) that is sure to bringout a seriesof lowerpriced imitations if there proves to bea market PROGRESSMARCHES ON for a standalone audio demod. You have two inputjacks (one Many new TVROreceivers were scheduledto be shownat type BNC,one RCA)and three output iacks; one monoand a SPTSWashington. We'll have a reporton whatwas operating pairfor stereooutput. The unit detectsstereo (a red lighton there in the Jung CSD. Priorto SPTShowever there were frontpanel glows) f romsources such as WFMTon transpon- somesignificant production changes, new models and other der 3. You driveyour audiosystem with the basebandaudio interestingreceiver wrinkles brought to the CSD Lab for outputs. evaluationand comment. We thought you would like to know Havingfull tuning rangeover the full 5.4 to 7.5 or so what we found. subcarrierregion is very handy. Unfortunately,however, ICM - InternationalCrystal Manufacturing Company has someof the audiosubs use a non-standardemphasis system broughtout a new model;the 4OOO.This looks very similar (ratherthan the 75 microsecond)and you get a slightlytinny to the 4300 seriesalthough it is a dramaticdeparture from effecton these musicservice channels. This will botherthe the 4300.On the front panel you havea two positionswitch true audiophilewho wantsevery note to be preciselyas it left to select6.2 or 6.8 MHzsubcarrier audio. You also have a the Oboe;for most of us it is barelynoticeable. Ultlmately new (vertical)signal strength meter which gives you a perhaps a front panel switchingde-emphasis network to relatlve readingof the systemgain. On the back panel matchthe rangeof strangeemphasis combinations being thereare a pairof audiooutputs (one for 6.2,the otherfor used in satellitetransmission might haveto be addedto a plus (for unitsuch as this. 6.8) a thirdaudio output the switchselected f ront - panelsignal). There is alsoa subcarrieroutput iack; this VIDIARK thefolks who have been turning out 8, l Oand1 2 givesyou the f ull spectrum between 5.4 and 7.5 MHz or so. foot Sphericaldesign antennas since shortly before SPTS We'llexplain that one shortly.A remotecontrol jack is also 80 in San Jose have gone into the receiverbusiness. on the rear panel. HaydenMcCullough got us an advancedprototype unit in The4OOO is the latesttechnology from lCM. lt hasthe new mid-Marchand we broughtit backto Providencialeswith divide by two PLL demodulatorsystem and the entire re- us.This is a singleconversion image reject mixer receiver ceiver has been re-laidout for ease of manufacture,test, that is availalein three different formats. The basicreceiver alignmentand trouble shooting.An adequate if not over gutsare the samein allthree; the bellsand whistles differ poweringfour page data sheet gives the techniciansome from one to another. assistanceon locatingwhat pot or controlon