AVCOM COM 3-R ANYl{AY h YOUTOOK i'l i \ st.r I \ hli AT ITOOO F': \ \ -l.'-.-' \ I\ ADMHASYOUR -l E\ rtF \ rr\ ANTENNA! E\ AND YOURTVRO SYSTEM. Rapid delivery onADM's super-eff icient 1 1 footpolar mount antenna(includes remote controlled polariza- tionrotation system as well!), plus, packages areavailable for completesystems including LNA, 24 channel tuneable receiverand cabling. Why wait in a longline when you can getthe best, today! A SUPERTVRO ANTENNA SYSTEM. High qualitypanelized aluminum 11 foot dish and steelpolar mount. Dish weighs approximate- ly 200pounds, mount 265 pounds. Precision designed,easy installation,zinc chromate baseprimed and heavy duty white top f inish. Therotating feed is standard ! Easily shipped and installed.Choice openings for dealers anddistributors. nt0nna lfeuelopment& lllanufacturirg,lnc P.0.Box 1178 PoolarBluff, Mo. 63901 (1-314-785-5988) T2-4/81 COOP'S out and pay $9,OOOor (shudder)$16,000 for an lnetalled terminal.ls pouringconcrete and hooking up some wire worth that much extra? I playedwith the SATFINDERfor severalhours. Remember this old boy hasseen more satellite television than probably anyoneelse in the worldtoday. This old boyfirst proved that 10 foot dishes will work back in 1978;coincidentally ona pipe cooP's mount less than 60 feet awayfrom wherethe SATFINDER now sits like a proudstatute in the frontof the Schneringer COMMENTON household.This old boy had to be torn away from the SATFINDERhours later and forced back to workon theApril TECHNOLOGY CSDbecause every hour in Oklahomahad been apportioned beforeI hit the groundhere. I likeDavid MacZura. He isa brightyoung man with a solid headon hisshoulders. His SATFINDER product is asfine as anythingI have everworked with in electronics. Inanyf ield. lt hasbeen carefully thought out so that evena littleold lady who hasdifficulty dialing a pushbutton telephone can swing DOINGIT RIGHT the remotecontrolled antenna from Fl on thewest to D3 on Returningto Oklahomaon March1 7th to puttogether this the east and stop at any of the 1 1 geostationarysatellites issueof the Dlgest RickSchneringerwas doing a'data-dump' alongthe way.Automatically on command,perfectly, with no on mein the 5Ominute ride from the airport.As we pulledover glitchesor problems.MacZura has learneda lessonI hope the lasthillwith the Arcadiaantenna farm on the horizonhe otherswill learn,soon. And that is that qualitycosts more said,as an aside,"Thore ls eomethlng nsw in the yard". I initiallybut in the long run it bringsresults which multiply innocentlyasked what it mightbe just as we toppedthe last manyfold.I doubt David has any unhappy customers in those ridge. 75 installationshe's done to date.He routinelygives custo- 'update' Theresquare in front of the house,right where I nevercould mers the opportunityto their remotecontrolled get grassto growsomething new had been planted; a tenfoot disheswith newer innovations. He commented that updating diameterSATFINDER dish. The site is perhaps75 feet from of older terminalsaccounted for $100,000in additional the world'sfirst private (licensed) terminal; the 20 foot mon- salesfor him in the pastsix monthsor so.I cannotimagine ster we installedmore than four years ago. Rick began any unhappycustomer paying even a dimemore for some- bubblingabout how wonderfulit was to have a dish that thinghe didn'tlike. tracked 11 satellitesat the pushof a keyboardentry com- MacZura'sten foot dishwith an AmplicaLNA (120)and mand.As we bothbounded out of the car DavidMacZura, the AVCOMreceiver zipped me through 57 activetransponders youngmanwhodeveloped thisunique systemcame outof the in lessthan three minutes time. lt producedbetter pictures houseto greetus. David knew I wasgoing to be intown and he fromANIK B downhere in Oklahoma(perfect on fivevideo was on handto showme how it worked. transponders)than I haveever seen hereon our 20 footer. Rlck bought thls dlsh for hlmself. The old 20 footer Yes,there are lessexpensive systems around. But I have moves all right,but 'with difficulty'.You don't go out and neverbeen as impressedwith the waya totalpackage works chase around the sky with it. I had visitedwith David in as I waswith thisone. David MacZura and company are to be Houstonwhere he first showedhis automatictracking sys- congratulatedbecause they have resisted the temptation to tem and wrote aboutit in the JanuaryCSD. I was impressed do somethingfor lessmoney; and they have the gutsto say then. I am even more impressednow. 'We onlysell the best". And then mean it. David does; he gives MacZurastarted out byattending the MiamiSPTS. He went a 'satisfaction or your mongy back' guaranteewith each home, to Tulsa,determined to be an installingdealer of installation.So far he hasn'thad any takers on returningthe terminals.Aftera number of falsestarts with various suppliers customer'smoney. he decided nobody really had their act together in the This industry needs more David MacZuras.lt needs antennadepartment so he set out to designone he could quality products that work so well the customercannot wait to manufactureand sell(with receivers and LNAshe buysas a showit offto thewhole neighborhood. That is what will make dealer)in the mid-west.He nowhas perhaps 75 installations homesatsreally take off; thousands, no tens of thousandsof in andoperating. They are not cheap Installatlons;starting dedicatedviewers who willfight for the continuedright to at $9,000and going up to $16,000.Most of thosesold were enjoyin their home unrestrictedsatellite television. David for the top dollar. MacZuraand company will be in Washingtonat SPTS'81. Why,in a dayand time when you can piece together the bits Attendhis'The Dealer Dilemma" seminar session and find andpartsfora home terminal forsay$25OOwould anyone go out for yourselfwhy doingit rightis the bestway to go! 'l COOP'SSATELLITEDICEST T3-4/81 v FIGUREONE N POLARMOUNT FORALL SEASONS THE MODIFIEDPOLAR MOUNT FIGURETWO In the searchfor the perfectantenna mount, the polar mountis often suggestedas beingthe best.However, as everyonesoon discovers, a true polarmount can't see any satellitesunless you happen to liveon the equator. As f lgure 1 shows,a truepolar mount has an axisof rotationparallel to the earth'saxis. But for most locationsthis causesthe antennato lookovor the satellites, which are relatively close to the earthin astronomicalterms. The f lrst attemptto correctthe polarmount's failings is illustratedin Figure2. Herethe axishas been tilted down so thatthe anten na points d irectly at the satellite. Now, however, rotatingthe antennaon it'saxis causes it to intersectthe satellitebelt in one or at most two locations, depending on the ) amountof tilt.This methodcan work adequatelyif all the I desiredsatellites are fairlyclose together. Glbson's Navi- gator'sManual suggests ways to adiustthis mount to tryto see the desiredsatellites. But no amountof trimmingcan makethis mountwork for allvisible satellites by rotationon FIGURETHREE it'ssingle axis. N The nextattempted improvemont might be to leavethe axisparallel to theearth's axis, but tlltthe antonnadown on theaxis. This is illustrated in Figurs 3. Notice that rotating the antennaon it'saxis now traces a conicalsurface. The inter- sectionof th is conical su rface with the equatorial plane wou ld be a circlecentered on the antennaaxis, Again, by adjust- mentof the antennaangle, perfect alignment can be ob- tainedat one or at mosttwo satellitelocations. Intuitively it seemsthat the errors at otherlocations for this conf iguration wouldbe lessthan thoseof Figure2. The maximumerror occursif we would try to lookat satellite 52. (Ihis assumes the earthdoes not attenuate4 GHz;not very practical!) lf we declde that the perfectmount would align on all satellites,even those on the far side of the earth:and we combinedour previous attempts, we havethe modifiedpolar mountillustrated in Figure4. Herewe havetaken the tilted antennafrom Figure 3 andcombined it withthe tilted axis of FIGUREFOUR Figure2. Once againrotating the antennaon it'saxis will N tracea conicalsurface. But this time the intersectionof this by RonaldWaltner 353 North Kenyon Indianapolis,lndiana 46219 TVROenthusiast Waltner has been supplying low-cost ($2) ) o geostationarysatellite aiming charts (computer derived) for severalyears now. His antenna pointing charts, referenced in STT's'Home Satellite Handbook', have proved very popular andCSD recommends the service. T4-4/81 COOP'SSATELLITEDICEST Axis AntennaSurface a:Latitude a*A:Axis/Earth Angle F:Antenna/AxisAngle B*A:"Look Angle"Referred to Axis rs+l h:resina . , ;:,;'(+ t(+) B+A:D-A) l;';"o'* 2A:D-B A+F+90"+B:180' A: F:1 SOqA-90%B:90o-B-A FIGUREFIVE conicalsurlace with the equatorialplane will be an elllpse Summlngthe angles around the left side of the vertical line becausethe axis is not perpendicularto the plane.lmmed- throughthe antennalocation: iatelythis tells us that onceagain we do not havethe perfect A+F+90'+B: 180. mountsince the satellitebelt is clearlycircular. The errors for F :180'- A-90'-B: 9o'-A-B this method should be less than the previousmethods, however,so let'stry somecalculations. We now haveall the datanecessary to set up our antenna. The key polnt to rememberis thatour antenna is mounted Our antennaaxis forms an angleof€+Awith respect to the at a fixedangle to the axisof rotation.Thus in Figure4 we earthat our location.The antenna has an additionaltilt of F havetilted our axisto makelook angles to S1 and 52 equal with respectto the axis. with respectto our axis Referringto Flgures6 and 7 we will calculate our Nowwe are readyto