George M Myers Radio Thchnque 70 Froehlkh Farm Rd HicksvlIIe NY 1801 ABSTRACT revised Myers/A berle test pro-transmitter least -50 dB F5 ±20 kHz cedure described results testing OWBAM transmitters use George Polks Aristocraft/High-Tec Challenger 720Steiner-modified Kraft synthesizer modules Ace RIC Model 91 givenThese produce AM signals sidebands about -35 dB F5 ±20 kHz 500 Hz frequen RC SYSTEM TESTINGthe modified Myers/cy accuracy Unfortunately radiate slightly Aberle test procedure Bob Aberle haveless power NBFM synthesizers modified test procedure original- None synthesizers will produce RC4O ly published January 1986 column slightlyso test matrix must work around limita match 1988 situation new test matrix tion times power output difference beis shown Figure 4 basic change has _________________________________________ tween AM FM Kraft modules must Pictures screen George Steiners spectrum analyzer show various intermodulation scenarios Figure 1 1 Two transmitters AM5O FM56 six ft apart Figure 2 R same two transmitters placed butt-to-butt FLS test horizontal scale two photos 200 kHzldiv photos use 10 dR/div vertical scale Figure 3 Below R Two transmitters AM5Oan OWBAM setand FM52 adjacent channels six ft apart Note prominence sidebands OWBAM transmitter Horizontal scale 50 kHzldiv 200 Ft Field Layout Test Distance CR ControlReceiverInterference TransmitterTransmitters field layout live testing Transmitter can butt-tobutt pair closer receiver under test can get glitching better Figure 5 shows what expect include specific tests differentiating between interference resulting 1988 narrow-band AM transmitters kind AM interference resulting old wideband transmitters OWBAM modified procedure uses several pieces test equipment have recali brated especially procedure NBFM transmitters use Kraft transmitters synthesized RF out-of-production switchable-radio-frequency modules FM modules have tested George Steiner reported least -55dB F5 ±20 kHz frequency accuracy better 500 Hz NBAM transmitter use Bobs Tower Hob bies Gold 500 transmitter pocket full special crystals individually checked frequen cy accuracy George Steiner Bobs Tower 34 Model Aviation RC 1988 Nats Gold/Silver RCMA transmitter stickers required entry Nats Transmitters will checked part Nats entry procedure before s Vince Mankowski Nats Manager considered dont have hiU set 01 crystals Tower transmitter provides fur ther limitation test tools arent perfect same tools used test results should fair comparison CAN proceed field testing before using what have Except matrix equipment changes procedure remains described Jan uary 1986 issue Model Aviation page 42 et seq No 31M testing FLS Test long time ago started using term 31M de scribe particular kind test ie test interfering transmitters placed butt-tobutt term 31M poorly chosen future will refer test FLS heres time concentrating creating field test third-order intermodulation interfer ence could performed reader resorting special test equipment FLS formerly 31M test setup DOES generate third-order intermodulation products also does other good things Figures 1 2 months column show photographs George Steiners spectrum analyzer screen displayed kinds interference see two transmitters silver-sticker AM transmitter RC5O gold-sticker FM transmitter RC56 placed six feet apart antennas parallel butt-tobutt antennas coaxial will note antennas parallel third- fifth- seventh-order intermodula tion signals generated inside spec trum analyzers RECEIVER show up tiny spikes riding low shoulders primary signals place transmitters butt-tobutt everything changes will note intermodulation signals generated side transmitters well inside receiv er much stronger consist funda Continued page 98 HAS MOVED INTO LARGER QUARTERS 21658 Cloud Way Hayward CA 94545 has acquired CB ASSOCIATES May 1988 35 r proud announce TATONE PRODUCTS CORPORATION CAL 415 783-4868 PRESIDENT Out CAL 800 482-8663TATONE PRODUCTS CORP4 ASW 24 ARF giant scale glider r No 3138 robbe ASW 24/s giant scale model newest Standard Class design worlds leading sailplane manufacturer Alexander Schleicher West Germany features latest double trapezoid wing geometry optimum lift distribution also famous F3B proven Quabeck /10-30/13-10-13 airfoil exceptional performance wide speed range Any RIC pilot will enjoy non-critical stall characteristics well balanced rudder response kit includes highly prefabricated components such white Plura fuselage balsa pre-sheeted foam core Siros wings stabilizer hardware cockpit interior insert pilot figure No special skills power tools necessary completion Building time short weekend Wing span 138 says aerobatic trainers have look ugly sleek lines robbe SUPERMAX remind full-scale airplane designed high performance docile trainer 46 four-stroke 50 two-stroke engine provides ample power perform aerobatic maneuver extremely rugged prefabricated Plura white fuselage combined balsa pre-sheeted Siros foam core wings other ready assemble components save lot building time SUPERMAX can easily built weekend Wing span 54 Mail rolbe Model SportAimn 180 Township Line Road Belle Mead NJ 08502 7 ceil version electric powered thermal soaring 10 ceil version rocket ship ilke cilmb performance one-piece Plura fuselage balsa-sheeted Siros wings other prefabricated components will get airborne no time Wing span 79 Good purchases $50 over dIrect robbe MM Soaring various types competi tions popular course Slope Racing Flying closed py lon course high-performance Sailpianes race wing tip wing tip incredible speeds attempt out-turn outrun rest competition best known Slope Race probably ISR Internation al Slope Race formerly sponsored RC Modeler now sponsored South Bay Soaring Society race draws contestants over world fea tures competition exciting will see form modeling Another type competition seen slope Combat Soaring one-on-one competition Sailplane trailing length magnetic tape cas sette point scored time plane comes contact tape other plane point also scored contact made other plane midairs happen frequently might think Combat provides exciting en tertaining diversion everyday flying thing have yet talked about flying site itself Basically need hill some wind specifi cally what needed respectable-sized hill wind blows straight slope thus producing rising air ideal slope site bowl created either curved hill series hills Such slope can pro duce lift wind blowing vari ety directions next windy day grab Sail plane find hill prepare yourself some exciting fun-filled fly ing have ever done As said before have contributions future arti cles Slope Soaring whether pic tures ideas stories whatever can send directly following ad dress Mark Triebes 20794 Kreisler Ct Saratoga CA 95070 Letters Editor Continued page 12 RC Club Inc Pennsylvania Am sending picture grandson Kiam myself As can see am start ing him off early age 16 months sure does love Pop Pops Goldberg J-3 Cub believe could fly now get Cub up about 36 mistakes high thank lot good reading Keep up good work Ray V Primaldi Willow Street PA Radio Technique/Myers Continued page 35 mental frequencies accompanied third fifth seventh ninth eleventh thirteenth etc intermodulation frequencies well points terest 1 intermodulation frequencies have power case Continued page 101 98 Model Aviation I@IIIN ircrafts FlyAbove Crowd Browse through latest robbe Catalog years hottest designs Youll find robbe offers better deal right price because robbe quality always pays off exciting kits see local dealer call robbe direct 201 359-2115 catalog over 200 pages full color action photos information mall coupon below today Just $6-CO plus youll receive bonus $400 refund certificate good toward next robbe purchase direct robbe* ARCUS VOrder No 3140 Gesigned renowned European contest pilots Arcus hottest dual-purpose 2-meter gilders ever standard dihedral set-up ailerons will satisfy demanding contest flyer novice wiil prefer polyhedral wing rudder elevator control Arcus can also electrified two optional electric filght sets SUPERMAX&Order No 3119A3118 Rush robbee new catalog Enclosed $6.. Check y Order 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW
Edition: Model Aviation - 1988/05
Page Numbers: 34, 35, 98, 101
George M Myers Radio Thchnque 70 Froehlkh Farm Rd HicksvlIIe NY 1801 ABSTRACT revised Myers/A berle test pro-transmitter least -50 dB F5 ±20 kHz cedure described results testing OWBAM transmitters use George Polks Aristocraft/High-Tec Challenger 720Steiner-modified Kraft synthesizer modules Ace RIC Model 91 givenThese produce AM signals sidebands about -35 dB F5 ±20 kHz 500 Hz frequen RC SYSTEM TESTINGthe modified Myers/cy accuracy Unfortunately radiate slightly Aberle test procedure Bob Aberle haveless power NBFM synthesizers modified test procedure original- None synthesizers will produce RC4O ly published January 1986 column slightlyso test matrix must work around limita match 1988 situation new test matrix tion times power output difference beis shown Figure 4 basic change has _________________________________________ tween AM FM Kraft modules must Pictures screen George Steiners spectrum analyzer show various intermodulation scenarios Figure 1 1 Two transmitters AM5O FM56 six ft apart Figure 2 R same two transmitters placed butt-to-butt FLS test horizontal scale two photos 200 kHzldiv photos use 10 dR/div vertical scale Figure 3 Below R Two transmitters AM5Oan OWBAM setand FM52 adjacent channels six ft apart Note prominence sidebands OWBAM transmitter Horizontal scale 50 kHzldiv 200 Ft Field Layout Test Distance CR ControlReceiverInterference TransmitterTransmitters field layout live testing Transmitter can butt-tobutt pair closer receiver under test can get glitching better Figure 5 shows what expect include specific tests differentiating between interference resulting 1988 narrow-band AM transmitters kind AM interference resulting old wideband transmitters OWBAM modified procedure uses several pieces test equipment have recali brated especially procedure NBFM transmitters use Kraft transmitters synthesized RF out-of-production switchable-radio-frequency modules FM modules have tested George Steiner reported least -55dB F5 ±20 kHz frequency accuracy better 500 Hz NBAM transmitter use Bobs Tower Hob bies Gold 500 transmitter pocket full special crystals individually checked frequen cy accuracy George Steiner Bobs Tower 34 Model Aviation RC 1988 Nats Gold/Silver RCMA transmitter stickers required entry Nats Transmitters will checked part Nats entry procedure before s Vince Mankowski Nats Manager considered dont have hiU set 01 crystals Tower transmitter provides fur ther limitation test tools arent perfect same tools used test results should fair comparison CAN proceed field testing before using what have Except matrix equipment changes procedure remains described Jan uary 1986 issue Model Aviation page 42 et seq No 31M testing FLS Test long time ago started using term 31M de scribe particular kind test ie test interfering transmitters placed butt-tobutt term 31M poorly chosen future will refer test FLS heres time concentrating creating field test third-order intermodulation interfer ence could performed reader resorting special test equipment FLS formerly 31M test setup DOES generate third-order intermodulation products also does other good things Figures 1 2 months column show photographs George Steiners spectrum analyzer screen displayed kinds interference see two transmitters silver-sticker AM transmitter RC5O gold-sticker FM transmitter RC56 placed six feet apart antennas parallel butt-tobutt antennas coaxial will note antennas parallel third- fifth- seventh-order intermodula tion signals generated inside spec trum analyzers RECEIVER show up tiny spikes riding low shoulders primary signals place transmitters butt-tobutt everything changes will note intermodulation signals generated side transmitters well inside receiv er much stronger consist funda Continued page 98 HAS MOVED INTO LARGER QUARTERS 21658 Cloud Way Hayward CA 94545 has acquired CB ASSOCIATES May 1988 35 r proud announce TATONE PRODUCTS CORPORATION CAL 415 783-4868 PRESIDENT Out CAL 800 482-8663TATONE PRODUCTS CORP4 ASW 24 ARF giant scale glider r No 3138 robbe ASW 24/s giant scale model newest Standard Class design worlds leading sailplane manufacturer Alexander Schleicher West Germany features latest double trapezoid wing geometry optimum lift distribution also famous F3B proven Quabeck /10-30/13-10-13 airfoil exceptional performance wide speed range Any RIC pilot will enjoy non-critical stall characteristics well balanced rudder response kit includes highly prefabricated components such white Plura fuselage balsa pre-sheeted foam core Siros wings stabilizer hardware cockpit interior insert pilot figure No special skills power tools necessary completion Building time short weekend Wing span 138 says aerobatic trainers have look ugly sleek lines robbe SUPERMAX remind full-scale airplane designed high performance docile trainer 46 four-stroke 50 two-stroke engine provides ample power perform aerobatic maneuver extremely rugged prefabricated Plura white fuselage combined balsa pre-sheeted Siros foam core wings other ready assemble components save lot building time SUPERMAX can easily built weekend Wing span 54 Mail rolbe Model SportAimn 180 Township Line Road Belle Mead NJ 08502 7 ceil version electric powered thermal soaring 10 ceil version rocket ship ilke cilmb performance one-piece Plura fuselage balsa-sheeted Siros wings other prefabricated components will get airborne no time Wing span 79 Good purchases $50 over dIrect robbe MM Soaring various types competi tions popular course Slope Racing Flying closed py lon course high-performance Sailpianes race wing tip wing tip incredible speeds attempt out-turn outrun rest competition best known Slope Race probably ISR Internation al Slope Race formerly sponsored RC Modeler now sponsored South Bay Soaring Society race draws contestants over world fea tures competition exciting will see form modeling Another type competition seen slope Combat Soaring one-on-one competition Sailplane trailing length magnetic tape cas sette point scored time plane comes contact tape other plane point also scored contact made other plane midairs happen frequently might think Combat provides exciting en tertaining diversion everyday flying thing have yet talked about flying site itself Basically need hill some wind specifi cally what needed respectable-sized hill wind blows straight slope thus producing rising air ideal slope site bowl created either curved hill series hills Such slope can pro duce lift wind blowing vari ety directions next windy day grab Sail plane find hill prepare yourself some exciting fun-filled fly ing have ever done As said before have contributions future arti cles Slope Soaring whether pic tures ideas stories whatever can send directly following ad dress Mark Triebes 20794 Kreisler Ct Saratoga CA 95070 Letters Editor Continued page 12 RC Club Inc Pennsylvania Am sending picture grandson Kiam myself As can see am start ing him off early age 16 months sure does love Pop Pops Goldberg J-3 Cub believe could fly now get Cub up about 36 mistakes high thank lot good reading Keep up good work Ray V Primaldi Willow Street PA Radio Technique/Myers Continued page 35 mental frequencies accompanied third fifth seventh ninth eleventh thirteenth etc intermodulation frequencies well points terest 1 intermodulation frequencies have power case Continued page 101 98 Model Aviation I@IIIN ircrafts FlyAbove Crowd Browse through latest robbe Catalog years hottest designs Youll find robbe offers better deal right price because robbe quality always pays off exciting kits see local dealer call robbe direct 201 359-2115 catalog over 200 pages full color action photos information mall coupon below today Just $6-CO plus youll receive bonus $400 refund certificate good toward next robbe purchase direct robbe* ARCUS VOrder No 3140 Gesigned renowned European contest pilots Arcus hottest dual-purpose 2-meter gilders ever standard dihedral set-up ailerons will satisfy demanding contest flyer novice wiil prefer polyhedral wing rudder elevator control Arcus can also electrified two optional electric filght sets SUPERMAX&Order No 3119A3118 Rush robbee new catalog Enclosed $6.. Check y Order 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW
Edition: Model Aviation - 1988/05
Page Numbers: 34, 35, 98, 101
George M Myers Radio Thchnque 70 Froehlkh Farm Rd HicksvlIIe NY 1801 ABSTRACT revised Myers/A berle test pro-transmitter least -50 dB F5 ±20 kHz cedure described results testing OWBAM transmitters use George Polks Aristocraft/High-Tec Challenger 720Steiner-modified Kraft synthesizer modules Ace RIC Model 91 givenThese produce AM signals sidebands about -35 dB F5 ±20 kHz 500 Hz frequen RC SYSTEM TESTINGthe modified Myers/cy accuracy Unfortunately radiate slightly Aberle test procedure Bob Aberle haveless power NBFM synthesizers modified test procedure original- None synthesizers will produce RC4O ly published January 1986 column slightlyso test matrix must work around limita match 1988 situation new test matrix tion times power output difference beis shown Figure 4 basic change has _________________________________________ tween AM FM Kraft modules must Pictures screen George Steiners spectrum analyzer show various intermodulation scenarios Figure 1 1 Two transmitters AM5O FM56 six ft apart Figure 2 R same two transmitters placed butt-to-butt FLS test horizontal scale two photos 200 kHzldiv photos use 10 dR/div vertical scale Figure 3 Below R Two transmitters AM5Oan OWBAM setand FM52 adjacent channels six ft apart Note prominence sidebands OWBAM transmitter Horizontal scale 50 kHzldiv 200 Ft Field Layout Test Distance CR ControlReceiverInterference TransmitterTransmitters field layout live testing Transmitter can butt-tobutt pair closer receiver under test can get glitching better Figure 5 shows what expect include specific tests differentiating between interference resulting 1988 narrow-band AM transmitters kind AM interference resulting old wideband transmitters OWBAM modified procedure uses several pieces test equipment have recali brated especially procedure NBFM transmitters use Kraft transmitters synthesized RF out-of-production switchable-radio-frequency modules FM modules have tested George Steiner reported least -55dB F5 ±20 kHz frequency accuracy better 500 Hz NBAM transmitter use Bobs Tower Hob bies Gold 500 transmitter pocket full special crystals individually checked frequen cy accuracy George Steiner Bobs Tower 34 Model Aviation RC 1988 Nats Gold/Silver RCMA transmitter stickers required entry Nats Transmitters will checked part Nats entry procedure before s Vince Mankowski Nats Manager considered dont have hiU set 01 crystals Tower transmitter provides fur ther limitation test tools arent perfect same tools used test results should fair comparison CAN proceed field testing before using what have Except matrix equipment changes procedure remains described Jan uary 1986 issue Model Aviation page 42 et seq No 31M testing FLS Test long time ago started using term 31M de scribe particular kind test ie test interfering transmitters placed butt-tobutt term 31M poorly chosen future will refer test FLS heres time concentrating creating field test third-order intermodulation interfer ence could performed reader resorting special test equipment FLS formerly 31M test setup DOES generate third-order intermodulation products also does other good things Figures 1 2 months column show photographs George Steiners spectrum analyzer screen displayed kinds interference see two transmitters silver-sticker AM transmitter RC5O gold-sticker FM transmitter RC56 placed six feet apart antennas parallel butt-tobutt antennas coaxial will note antennas parallel third- fifth- seventh-order intermodula tion signals generated inside spec trum analyzers RECEIVER show up tiny spikes riding low shoulders primary signals place transmitters butt-tobutt everything changes will note intermodulation signals generated side transmitters well inside receiv er much stronger consist funda Continued page 98 HAS MOVED INTO LARGER QUARTERS 21658 Cloud Way Hayward CA 94545 has acquired CB ASSOCIATES May 1988 35 r proud announce TATONE PRODUCTS CORPORATION CAL 415 783-4868 PRESIDENT Out CAL 800 482-8663TATONE PRODUCTS CORP4 ASW 24 ARF giant scale glider r No 3138 robbe ASW 24/s giant scale model newest Standard Class design worlds leading sailplane manufacturer Alexander Schleicher West Germany features latest double trapezoid wing geometry optimum lift distribution also famous F3B proven Quabeck /10-30/13-10-13 airfoil exceptional performance wide speed range Any RIC pilot will enjoy non-critical stall characteristics well balanced rudder response kit includes highly prefabricated components such white Plura fuselage balsa pre-sheeted foam core Siros wings stabilizer hardware cockpit interior insert pilot figure No special skills power tools necessary completion Building time short weekend Wing span 138 says aerobatic trainers have look ugly sleek lines robbe SUPERMAX remind full-scale airplane designed high performance docile trainer 46 four-stroke 50 two-stroke engine provides ample power perform aerobatic maneuver extremely rugged prefabricated Plura white fuselage combined balsa pre-sheeted Siros foam core wings other ready assemble components save lot building time SUPERMAX can easily built weekend Wing span 54 Mail rolbe Model SportAimn 180 Township Line Road Belle Mead NJ 08502 7 ceil version electric powered thermal soaring 10 ceil version rocket ship ilke cilmb performance one-piece Plura fuselage balsa-sheeted Siros wings other prefabricated components will get airborne no time Wing span 79 Good purchases $50 over dIrect robbe MM Soaring various types competi tions popular course Slope Racing Flying closed py lon course high-performance Sailpianes race wing tip wing tip incredible speeds attempt out-turn outrun rest competition best known Slope Race probably ISR Internation al Slope Race formerly sponsored RC Modeler now sponsored South Bay Soaring Society race draws contestants over world fea tures competition exciting will see form modeling Another type competition seen slope Combat Soaring one-on-one competition Sailplane trailing length magnetic tape cas sette point scored time plane comes contact tape other plane point also scored contact made other plane midairs happen frequently might think Combat provides exciting en tertaining diversion everyday flying thing have yet talked about flying site itself Basically need hill some wind specifi cally what needed respectable-sized hill wind blows straight slope thus producing rising air ideal slope site bowl created either curved hill series hills Such slope can pro duce lift wind blowing vari ety directions next windy day grab Sail plane find hill prepare yourself some exciting fun-filled fly ing have ever done As said before have contributions future arti cles Slope Soaring whether pic tures ideas stories whatever can send directly following ad dress Mark Triebes 20794 Kreisler Ct Saratoga CA 95070 Letters Editor Continued page 12 RC Club Inc Pennsylvania Am sending picture grandson Kiam myself As can see am start ing him off early age 16 months sure does love Pop Pops Goldberg J-3 Cub believe could fly now get Cub up about 36 mistakes high thank lot good reading Keep up good work Ray V Primaldi Willow Street PA Radio Technique/Myers Continued page 35 mental frequencies accompanied third fifth seventh ninth eleventh thirteenth etc intermodulation frequencies well points terest 1 intermodulation frequencies have power case Continued page 101 98 Model Aviation I@IIIN ircrafts FlyAbove Crowd Browse through latest robbe Catalog years hottest designs Youll find robbe offers better deal right price because robbe quality always pays off exciting kits see local dealer call robbe direct 201 359-2115 catalog over 200 pages full color action photos information mall coupon below today Just $6-CO plus youll receive bonus $400 refund certificate good toward next robbe purchase direct robbe* ARCUS VOrder No 3140 Gesigned renowned European contest pilots Arcus hottest dual-purpose 2-meter gilders ever standard dihedral set-up ailerons will satisfy demanding contest flyer novice wiil prefer polyhedral wing rudder elevator control Arcus can also electrified two optional electric filght sets SUPERMAX&Order No 3119A3118 Rush robbee new catalog Enclosed $6.. Check y Order 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW
Edition: Model Aviation - 1988/05
Page Numbers: 34, 35, 98, 101
George M Myers Radio Thchnque 70 Froehlkh Farm Rd HicksvlIIe NY 1801 ABSTRACT revised Myers/A berle test pro-transmitter least -50 dB F5 ±20 kHz cedure described results testing OWBAM transmitters use George Polks Aristocraft/High-Tec Challenger 720Steiner-modified Kraft synthesizer modules Ace RIC Model 91 givenThese produce AM signals sidebands about -35 dB F5 ±20 kHz 500 Hz frequen RC SYSTEM TESTINGthe modified Myers/cy accuracy Unfortunately radiate slightly Aberle test procedure Bob Aberle haveless power NBFM synthesizers modified test procedure original- None synthesizers will produce RC4O ly published January 1986 column slightlyso test matrix must work around limita match 1988 situation new test matrix tion times power output difference beis shown Figure 4 basic change has _________________________________________ tween AM FM Kraft modules must Pictures screen George Steiners spectrum analyzer show various intermodulation scenarios Figure 1 1 Two transmitters AM5O FM56 six ft apart Figure 2 R same two transmitters placed butt-to-butt FLS test horizontal scale two photos 200 kHzldiv photos use 10 dR/div vertical scale Figure 3 Below R Two transmitters AM5Oan OWBAM setand FM52 adjacent channels six ft apart Note prominence sidebands OWBAM transmitter Horizontal scale 50 kHzldiv 200 Ft Field Layout Test Distance CR ControlReceiverInterference TransmitterTransmitters field layout live testing Transmitter can butt-tobutt pair closer receiver under test can get glitching better Figure 5 shows what expect include specific tests differentiating between interference resulting 1988 narrow-band AM transmitters kind AM interference resulting old wideband transmitters OWBAM modified procedure uses several pieces test equipment have recali brated especially procedure NBFM transmitters use Kraft transmitters synthesized RF out-of-production switchable-radio-frequency modules FM modules have tested George Steiner reported least -55dB F5 ±20 kHz frequency accuracy better 500 Hz NBAM transmitter use Bobs Tower Hob bies Gold 500 transmitter pocket full special crystals individually checked frequen cy accuracy George Steiner Bobs Tower 34 Model Aviation RC 1988 Nats Gold/Silver RCMA transmitter stickers required entry Nats Transmitters will checked part Nats entry procedure before s Vince Mankowski Nats Manager considered dont have hiU set 01 crystals Tower transmitter provides fur ther limitation test tools arent perfect same tools used test results should fair comparison CAN proceed field testing before using what have Except matrix equipment changes procedure remains described Jan uary 1986 issue Model Aviation page 42 et seq No 31M testing FLS Test long time ago started using term 31M de scribe particular kind test ie test interfering transmitters placed butt-tobutt term 31M poorly chosen future will refer test FLS heres time concentrating creating field test third-order intermodulation interfer ence could performed reader resorting special test equipment FLS formerly 31M test setup DOES generate third-order intermodulation products also does other good things Figures 1 2 months column show photographs George Steiners spectrum analyzer screen displayed kinds interference see two transmitters silver-sticker AM transmitter RC5O gold-sticker FM transmitter RC56 placed six feet apart antennas parallel butt-tobutt antennas coaxial will note antennas parallel third- fifth- seventh-order intermodula tion signals generated inside spec trum analyzers RECEIVER show up tiny spikes riding low shoulders primary signals place transmitters butt-tobutt everything changes will note intermodulation signals generated side transmitters well inside receiv er much stronger consist funda Continued page 98 HAS MOVED INTO LARGER QUARTERS 21658 Cloud Way Hayward CA 94545 has acquired CB ASSOCIATES May 1988 35 r proud announce TATONE PRODUCTS CORPORATION CAL 415 783-4868 PRESIDENT Out CAL 800 482-8663TATONE PRODUCTS CORP4 ASW 24 ARF giant scale glider r No 3138 robbe ASW 24/s giant scale model newest Standard Class design worlds leading sailplane manufacturer Alexander Schleicher West Germany features latest double trapezoid wing geometry optimum lift distribution also famous F3B proven Quabeck /10-30/13-10-13 airfoil exceptional performance wide speed range Any RIC pilot will enjoy non-critical stall characteristics well balanced rudder response kit includes highly prefabricated components such white Plura fuselage balsa pre-sheeted foam core Siros wings stabilizer hardware cockpit interior insert pilot figure No special skills power tools necessary completion Building time short weekend Wing span 138 says aerobatic trainers have look ugly sleek lines robbe SUPERMAX remind full-scale airplane designed high performance docile trainer 46 four-stroke 50 two-stroke engine provides ample power perform aerobatic maneuver extremely rugged prefabricated Plura white fuselage combined balsa pre-sheeted Siros foam core wings other ready assemble components save lot building time SUPERMAX can easily built weekend Wing span 54 Mail rolbe Model SportAimn 180 Township Line Road Belle Mead NJ 08502 7 ceil version electric powered thermal soaring 10 ceil version rocket ship ilke cilmb performance one-piece Plura fuselage balsa-sheeted Siros wings other prefabricated components will get airborne no time Wing span 79 Good purchases $50 over dIrect robbe MM Soaring various types competi tions popular course Slope Racing Flying closed py lon course high-performance Sailpianes race wing tip wing tip incredible speeds attempt out-turn outrun rest competition best known Slope Race probably ISR Internation al Slope Race formerly sponsored RC Modeler now sponsored South Bay Soaring Society race draws contestants over world fea tures competition exciting will see form modeling Another type competition seen slope Combat Soaring one-on-one competition Sailplane trailing length magnetic tape cas sette point scored time plane comes contact tape other plane point also scored contact made other plane midairs happen frequently might think Combat provides exciting en tertaining diversion everyday flying thing have yet talked about flying site itself Basically need hill some wind specifi cally what needed respectable-sized hill wind blows straight slope thus producing rising air ideal slope site bowl created either curved hill series hills Such slope can pro duce lift wind blowing vari ety directions next windy day grab Sail plane find hill prepare yourself some exciting fun-filled fly ing have ever done As said before have contributions future arti cles Slope Soaring whether pic tures ideas stories whatever can send directly following ad dress Mark Triebes 20794 Kreisler Ct Saratoga CA 95070 Letters Editor Continued page 12 RC Club Inc Pennsylvania Am sending picture grandson Kiam myself As can see am start ing him off early age 16 months sure does love Pop Pops Goldberg J-3 Cub believe could fly now get Cub up about 36 mistakes high thank lot good reading Keep up good work Ray V Primaldi Willow Street PA Radio Technique/Myers Continued page 35 mental frequencies accompanied third fifth seventh ninth eleventh thirteenth etc intermodulation frequencies well points terest 1 intermodulation frequencies have power case Continued page 101 98 Model Aviation I@IIIN ircrafts FlyAbove Crowd Browse through latest robbe Catalog years hottest designs Youll find robbe offers better deal right price because robbe quality always pays off exciting kits see local dealer call robbe direct 201 359-2115 catalog over 200 pages full color action photos information mall coupon below today Just $6-CO plus youll receive bonus $400 refund certificate good toward next robbe purchase direct robbe* ARCUS VOrder No 3140 Gesigned renowned European contest pilots Arcus hottest dual-purpose 2-meter gilders ever standard dihedral set-up ailerons will satisfy demanding contest flyer novice wiil prefer polyhedral wing rudder elevator control Arcus can also electrified two optional electric filght sets SUPERMAX&Order No 3119A3118 Rush robbee new catalog Enclosed $6.. Check y Order 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW