Radio Technique George M Myers USEFUL TOOLS long have playing things electronic VOM AC/DC Volt-Ohm Meter has reigned king electronic tools. ntial tool Occa sionally needs specialized tools like oscilloscope bench power supply servo cycler battery tester digital pulse meter etc can still accomplish useful things have VOM skill use Now am about describe VAT Volt/Amp/Tachometer first tool offered RC use presents serious challenge supremacy VOM subject Accu-Tach 2 Nor Cal Avionics Inc PO Box 70956 Sunnyvale CA 94088 Accu-Tach 2 combines digital DC centivoltmeter DC milliammeter optical tachom eter handy package will fit neatly anybodys field box life Ive farsighted great seeing model distance good reading telephone book Accu-Tach 2 LCD display uses big x A-inch numbers display values between plus minus 1999 can read glasses am grateful hate wear anything safety sun glasses Perhaps will find easy read also permissible viewing angle good numbers can read 450 off perpendicular directions Accu-Tach 2 will following 1 Measure DC battery Voltage range thru 1999 centi-volts call 0 VDC shunting circuit under test 600K ohms resis tance large enough minimize circuit loading Accu-Tach 2 can used poking around inside receivers volt age range fine aligning receivers well diagnosing troubles kinds likely encountered transmitters receivers servos battery packs 2 Measure rpm range 10 35000 rpm optically No dangerous contact rotating machinery necessary range adequate gasoline- alcohol-fueled engines whether idle maximum rpm well electric motors such used power model airplanes tachom eter will satisfy needs customary sport competition models ducted fans helicopters etc 3 Measure DC current range /- 1 thru 1999 mA call /- 2 amps range nicely fits kinds RC uses such measuring charging cur rents measuring discharge currents typical transmitters servos full RC systems 4 Measure battery pack voltage under load nominal 200 mA Again range volts minimum indication 10 mV So much capabilities now lets look some applications Tachometer Push switch left side case towards tachometer eye top case point eye towards whirling propeller keeping six-inch clearance read rpm Two measuring ranges provided rpm/l0 rpm/100 counter works 70000 pulses per minute good 35000 rpm two-bladed propeller display-scaling circuitry set up use two-bladed propeller Point two-bladed prop read correct rpm range 10 35000 rpm divided either 10 100 depending front-panel switch position chose using single-bladed prop multiply number indicated factor 2 prop has three blades multi ply indicated number % prop has four blades multiply indica tion etc As can see case multiplier found using two divided number blades Its little fussy about propeller il luminated point lens Ive always able find some position will read properly Milliammeter panel marked Amps meter indicates directly milliamps range interest RCers measuring voltage drop across meter current running through calculated series insertion 105 ohms /- 5% ammeter limited maximum two amps because internal cir cuitry set up way because display limited 1999 counts ICs notoriously intolerant overloads Bob Aberles suggestion made red lead fused ammeter lead insert ing Radio Shack Inline Mini Fuse Holder No 270-1238 used two-amp fuse No 270-1244 increases inser tion resistance about 45 ohms may too much some tests its handy Ive already blown couple fuses Accu-Tach 2 still works must good idea Thanks Bob As example its use Accu-Tach 2 indicated 680 mA MEN C/50-4 34Model Aviation Accu-Tach 2 wIth hIgh-current ada p tsr fused test lead common lead George tells us get good usage out thIs versatile instrumentfor better RC flying charger pumping up SR900 bat tery pack High Rate 41 mA chargers LED went out very close what iron-vane ammeter reads should able measure charg ing current used RC equipment Making use idea presented RT back October 1979 Accu Tach 2 handbook suggests used evaluate RC system installation Since everyone should make such evalua tions since device makes doing convenient Ill go over proce dure again need cut battery lead aileron-extender cable connect cut ends milliammeter like Accu-Tach 2 Put adapter tween flight pack switch harness Turn transmitter receiver observe current being drawn try control its extreme position trim available same extreme can stall servo position will see amps jump way up stay up warning reset throttle stop clear epoxy out hinges make additional clearance pushrods etc can put modified aileron extender-cable between servo receiver evaluate particular servo installation problems may work system installation stability margin setup low enough insertion resistance Accu-Tach 2 oscilla tor strobes display may drive system instability Centivoitmeter meter indicates centivolts what else would call meter shows cV battery pack has terminal voltage Volts Id happier front panel marked cV instead Volts Either automatic decimal point should have provided decimal point moves around lot machine Ive already mentioned some customary voltmeter uses above Heres another Since Accu-Tach 2 indicates numbers small 10 mV same i cv can use peak-detection charging hurry set up charging rate will get job done 15 minutes mom tor battery terminal voltage see voltage drop 2 cV below what few seconds before charging complete must caution overcharging high rate can ruin battery must pay attention what doing should battery pack cool touch pack will get quite warm during charging should never get hot gets hot stays hot know youve just junked battery pack Now heres equipment mix TACHOMETER : _____________________________________ VOLT/AMP ACCU-TAcH2 METER Rx p Tx Corn 1999 CENTI VOLTS DC 1999M1LL1-N AMPS DC HIGH-CURRENT * ADAPTER FOR ESV ESV COMMON LEAD FOR ALL MEASUREMENTS TX& RPM/b I-i I] RXEI RPM/100 Heres what switches Inputs AccuTach 2 match crowd can measure control pulses coming out receiver deter positive- negative-going can determine whether use some substitute servos Connect Com mon lead battery Negative Connect Positive Volts lead signal lead coming out receiver Push common pin thru servo pigtail necessary Now voltage shows about 25 cV looking positive-going pulses reads about 380 cV have negative-going pulses very rare ESV expanded-scale voltmeter some built-in loading resistors switch-selected transmitter 60 ohms flight pack 30 ohms cause nominal drain 167 mA adequate compromise test majori ty RC equipment Loaded way Accu-Tach 2 can expect good fully-charged pack discharged about three hours An adapter offered loading large packs 48 6 VDC 900 mAh up 417 mA ESV test consists 20 ohm/S watt resistor GR plug plug adapter Accu-Tach 2 plug test leads adapter 417 mA drain representative large-servo service conditions get realistic test larger packs adapter As Bob Aberle pointed out should remember adapter plugs same sockets used transmitter testing just flip switch Accu-Tach 2 front panel However wouldnt want use adapter testing 10- 12-volt transmitter pack 12-volt starter battery because adapter will draw excessive current transmitter pack loading resistor will get very hot stink Guess know can use Accu-Tach 2 kinds battery testing needing clock pencil paper some kind Continued page 127 TO TO AMP COM OR BATTE 3ZL can make systemlammeter test cable aileron extension cable Use test overloads servos general health RC system etc February 198535 I V med Just try Thats grabbed transmitter Don fly wing land feet needed funny mushrooms about must answer guys tried help RTF dropped wing badly up aileron Only Ken Willard provided faint clue answer plane heavy flyable Ailerons narrow strip differentialmore up down high loadings angle narrow up-aileron excessive movement spoiled killed lift volved wing panel Conclusions Dont use too much movement because narrow strip limitations widen ailerons use less movement forget differential un less have barndoor aileron suf ficient aileron chord workable modest movements probably symmetrical semi-symmetrical airfoils Differential does help down-aileron yawbut sign inadequate vertical area Almost dark railbirds didnt want go home Leaving asked disbe lief see no sleeping bags replied guys actually sit until after dark feeling good aight told full moon came up fliers being what guy offered another plane shoot go-rounds moonlight approach cloud hid moon guy still got Full moon Eloy Marez writes four-cycles MAN well indeed urges En joy upcoming building season unfor tunately dont get %$c&&c!* Au Thats direct quote forced fly year long heart bleeds all-year guys gotta build too An October day takes make yearin Land Oz Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 35 load testing glow battery starter battery complete test kit Other ideas Ive mentioned few uses Accu-Tach 2 little effort can find others item might offer some difficulty will figuring out measure resistance ohms Unfortunately wont find simple way meters sensitivity too low therefore currents would have put through item under test would destructive unless want build some kind external power supply amplifier decade switch time get done will have spent price pretty good VOM So King VOM hangs onto portion realm Accu-Tach 2 comes clip leads have make own used General Radio GR twin banana plugs Continued page 130 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro %Lubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc5%Castor Oil$775$695$675$650 4-cycle70/0Castor/Syn$850$765$750$725 4-cycle15%Castor/Syn$995$895$850$825 lOs100/0Synthetic$895$795$750$725 lOc10%Castor Oil$895$795$750$725 R/G12%Syn/Castor$995$895$850$825 iSs15%Synthetic$995$895$850$825 20c200/0Castor Oil$1395$1250$1200$1150 25s25%Synthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 505Q0/iSynthetic$2395$2100$2050$2000 60600/oSynthetic$2695$2400$2300$2200 IN CONTINENTAL USA SHELDONSHours M/C VISAHOBBY SHOPMon Wed Fn&Sat 930 530 3157 Alum Rock AvenueThur 930-900 24-124 Gal shipped via truckSan Jose California 95127Sun 1200-500 UPSCOD-Sl65 408 251-0787 TEE PIlE IS EIGHT So spend extra money spots will last least 2 wated time r flIed years after purchase tires Flat spots poor unconditIonally durability problem wth wheels9 Wth D Marcovecch 0 Available 7/2 & 8 sizes vintage II get wheel military styles Smooth guaranteed develop flat embossed spoked covers available 0For compieie brochure send $1 io D Maivovecchio welcome dealer inquires PER PAIR PO Box 37 ingviiie 11738 February 1985127 Price 2995 I- V_______________ Miter Master Mite Mast, tool designed enable crafts man make perfect joints wood accurately sanding pre-setangles TlresquaringfencejAj allomsforprecisegO angles retracts below surface Any angle can beset triangular guide using adjacent side complement angle mill funned making invaluable truss construction new cyanoacrylate adhesives require accurately fitted joints achieve fulf strength Miter Master mill enable make theni easrly FOURMOST PRODUCTS 4040 24th Ave Forest Grove OR 97116 Radio Technique/Myers Continued page 127 some patch cords salvaged old piece test gear being discarded might have buy somewhere Radio Shack offers several options cluding GR plugs thats no problem prefer unit has wire stand back case holds con venient viewing angle made characteristic Accu-Tach 2 dont like its long settling time uses five seconds reach its final reading accustomed instantaneous response dArsenval meter five seconds seems like very long time other hand delay really isnt critical unless trying trap some transient phenomenon trying probably should using oscilloscope strip-chart recorder Till meet again George M Myers 70 Froehlich Farm Rd. Hicksville NY 11801 friendly Price $950 Assemsleo booed 503 357-2732 AMA Frequency Committee Chairman PS know friendly District Frequency Coordinator Are having interference problems Tell him DFC about 0MM Glitch Buster/Utasi Continued page 38 little bit better noise immunity especial ly metal-to- ictal noise Thats see Helicopter pilots using FM AM fine too What dont see discussed anywhere AM receiver design has less noise front-end circuitry Most certainly new narrow-band designs first-rate offer good selectivity sensitivity around good performance Trouble someone frequency turns its over tears FM really lucky might just get someone turns antenna down signal still keeps receiver captured seems Im never lucky Maybe luck better us can afford PCM system Contrary popular belief someone frequency turns will still crash likely difference crash interference weak inter mittent system may able read between lines maintain con trol although response may seem slow sluggish interference serious constant receiver may go fail-safe mode servos move predetermined position flying Buzzard Bombshell some other Old-Timer may fine youre flying 30-lb ship 5 hp neutral stability Id head cover way pay money take chances could afford Id fly PCM about different glitch stop gadgets available Basically devices consist signal buffers made logic device called buffer inverter boosts signal strength servo presents noise signal line getting back decoder cases devices trick unless have serious problem Another good item helps solve problems system allows use separate battery packs powering receiver servos RAM has such product market goes long way toward cleaning up lots problems created long leads noisy servo motors cases switching sepa rate battery packs receiver ser vos will completely eradicate glitch problems Its little extra wiring re quires some extra patience results well worth Finally get hear something really new After spending about two days phone long distance calls uncovered new theory about long leads glitches comes long-time RF expert has designed some popu lar radios around today seems days receiver designs use what re ferred single-ended front end Continued page 132 Specifications Wing Area 1500 sq Span 7-2 Weight 20-25 lbs Engine 20-37 Fuselage Formers/Planking Wing Foam 3/32 Sheeting Stab Fin Solid Sheet Clear Canopy/All Balsa Major Decals Included Kit I99~ Sure winner ScaleOH Residents add 6 % tan Send $100 complete catalogueVideo Tapes 0-130 B-29 also available VHS BETA $2995 RIO Mfg 706 Easton NE North Canton OH 44721 216-499-5323 130Model Aviation NEW FOURMOST PRODUCTS FUSELAGE FIXTURE FOURMOST FUSELAGE FIXTURE designed Aadeantically align fuselage structures built strings measuring eveballing Simply slide tour centering brackets track until align firewall tail joint two bulkheads Clamp hselagetogetherlightly mith rubberbands structure will straight track New 1/5 Scale Sea Fury Beautiful Stable Flyer Capable AllAerobatlc C Yes invited So joIn National Soaring Society OFFICIAL SOARING SPECIAL INTERFET GROUP YEARLY NATIONAL TOURNAMENTS NATION-WIDE EXCELLENCE AWARDS PRoGRAM C EXCELLENT al-MONTHLY NEWSLETTER NSS CONTRIBUTES SUBSTANTIAL AMOUNTS TO EACH F3B SOARING TEAM NES IS RESPONSIBLE FOR THE ORGANIZATION AND OVERSEEING OF AMA NATS INCLUDING AWARDS BANOUET YEARLY DUES ARE $1200 ISPECIAL FAMILY RATES NSS OFFICERS ARE FROM ALL 11 DISTRICTS lor Information Contscts JOHN R VOGEL 90k ORCHARD PARK DR GISSONIA PA 15044
Edition: Model Aviation - 1985/02
Page Numbers: 34, 35, 127, 130
Radio Technique George M Myers USEFUL TOOLS long have playing things electronic VOM AC/DC Volt-Ohm Meter has reigned king electronic tools. ntial tool Occa sionally needs specialized tools like oscilloscope bench power supply servo cycler battery tester digital pulse meter etc can still accomplish useful things have VOM skill use Now am about describe VAT Volt/Amp/Tachometer first tool offered RC use presents serious challenge supremacy VOM subject Accu-Tach 2 Nor Cal Avionics Inc PO Box 70956 Sunnyvale CA 94088 Accu-Tach 2 combines digital DC centivoltmeter DC milliammeter optical tachom eter handy package will fit neatly anybodys field box life Ive farsighted great seeing model distance good reading telephone book Accu-Tach 2 LCD display uses big x A-inch numbers display values between plus minus 1999 can read glasses am grateful hate wear anything safety sun glasses Perhaps will find easy read also permissible viewing angle good numbers can read 450 off perpendicular directions Accu-Tach 2 will following 1 Measure DC battery Voltage range thru 1999 centi-volts call 0 VDC shunting circuit under test 600K ohms resis tance large enough minimize circuit loading Accu-Tach 2 can used poking around inside receivers volt age range fine aligning receivers well diagnosing troubles kinds likely encountered transmitters receivers servos battery packs 2 Measure rpm range 10 35000 rpm optically No dangerous contact rotating machinery necessary range adequate gasoline- alcohol-fueled engines whether idle maximum rpm well electric motors such used power model airplanes tachom eter will satisfy needs customary sport competition models ducted fans helicopters etc 3 Measure DC current range /- 1 thru 1999 mA call /- 2 amps range nicely fits kinds RC uses such measuring charging cur rents measuring discharge currents typical transmitters servos full RC systems 4 Measure battery pack voltage under load nominal 200 mA Again range volts minimum indication 10 mV So much capabilities now lets look some applications Tachometer Push switch left side case towards tachometer eye top case point eye towards whirling propeller keeping six-inch clearance read rpm Two measuring ranges provided rpm/l0 rpm/100 counter works 70000 pulses per minute good 35000 rpm two-bladed propeller display-scaling circuitry set up use two-bladed propeller Point two-bladed prop read correct rpm range 10 35000 rpm divided either 10 100 depending front-panel switch position chose using single-bladed prop multiply number indicated factor 2 prop has three blades multi ply indicated number % prop has four blades multiply indica tion etc As can see case multiplier found using two divided number blades Its little fussy about propeller il luminated point lens Ive always able find some position will read properly Milliammeter panel marked Amps meter indicates directly milliamps range interest RCers measuring voltage drop across meter current running through calculated series insertion 105 ohms /- 5% ammeter limited maximum two amps because internal cir cuitry set up way because display limited 1999 counts ICs notoriously intolerant overloads Bob Aberles suggestion made red lead fused ammeter lead insert ing Radio Shack Inline Mini Fuse Holder No 270-1238 used two-amp fuse No 270-1244 increases inser tion resistance about 45 ohms may too much some tests its handy Ive already blown couple fuses Accu-Tach 2 still works must good idea Thanks Bob As example its use Accu-Tach 2 indicated 680 mA MEN C/50-4 34Model Aviation Accu-Tach 2 wIth hIgh-current ada p tsr fused test lead common lead George tells us get good usage out thIs versatile instrumentfor better RC flying charger pumping up SR900 bat tery pack High Rate 41 mA chargers LED went out very close what iron-vane ammeter reads should able measure charg ing current used RC equipment Making use idea presented RT back October 1979 Accu Tach 2 handbook suggests used evaluate RC system installation Since everyone should make such evalua tions since device makes doing convenient Ill go over proce dure again need cut battery lead aileron-extender cable connect cut ends milliammeter like Accu-Tach 2 Put adapter tween flight pack switch harness Turn transmitter receiver observe current being drawn try control its extreme position trim available same extreme can stall servo position will see amps jump way up stay up warning reset throttle stop clear epoxy out hinges make additional clearance pushrods etc can put modified aileron extender-cable between servo receiver evaluate particular servo installation problems may work system installation stability margin setup low enough insertion resistance Accu-Tach 2 oscilla tor strobes display may drive system instability Centivoitmeter meter indicates centivolts what else would call meter shows cV battery pack has terminal voltage Volts Id happier front panel marked cV instead Volts Either automatic decimal point should have provided decimal point moves around lot machine Ive already mentioned some customary voltmeter uses above Heres another Since Accu-Tach 2 indicates numbers small 10 mV same i cv can use peak-detection charging hurry set up charging rate will get job done 15 minutes mom tor battery terminal voltage see voltage drop 2 cV below what few seconds before charging complete must caution overcharging high rate can ruin battery must pay attention what doing should battery pack cool touch pack will get quite warm during charging should never get hot gets hot stays hot know youve just junked battery pack Now heres equipment mix TACHOMETER : _____________________________________ VOLT/AMP ACCU-TAcH2 METER Rx p Tx Corn 1999 CENTI VOLTS DC 1999M1LL1-N AMPS DC HIGH-CURRENT * ADAPTER FOR ESV ESV COMMON LEAD FOR ALL MEASUREMENTS TX& RPM/b I-i I] RXEI RPM/100 Heres what switches Inputs AccuTach 2 match crowd can measure control pulses coming out receiver deter positive- negative-going can determine whether use some substitute servos Connect Com mon lead battery Negative Connect Positive Volts lead signal lead coming out receiver Push common pin thru servo pigtail necessary Now voltage shows about 25 cV looking positive-going pulses reads about 380 cV have negative-going pulses very rare ESV expanded-scale voltmeter some built-in loading resistors switch-selected transmitter 60 ohms flight pack 30 ohms cause nominal drain 167 mA adequate compromise test majori ty RC equipment Loaded way Accu-Tach 2 can expect good fully-charged pack discharged about three hours An adapter offered loading large packs 48 6 VDC 900 mAh up 417 mA ESV test consists 20 ohm/S watt resistor GR plug plug adapter Accu-Tach 2 plug test leads adapter 417 mA drain representative large-servo service conditions get realistic test larger packs adapter As Bob Aberle pointed out should remember adapter plugs same sockets used transmitter testing just flip switch Accu-Tach 2 front panel However wouldnt want use adapter testing 10- 12-volt transmitter pack 12-volt starter battery because adapter will draw excessive current transmitter pack loading resistor will get very hot stink Guess know can use Accu-Tach 2 kinds battery testing needing clock pencil paper some kind Continued page 127 TO TO AMP COM OR BATTE 3ZL can make systemlammeter test cable aileron extension cable Use test overloads servos general health RC system etc February 198535 I V med Just try Thats grabbed transmitter Don fly wing land feet needed funny mushrooms about must answer guys tried help RTF dropped wing badly up aileron Only Ken Willard provided faint clue answer plane heavy flyable Ailerons narrow strip differentialmore up down high loadings angle narrow up-aileron excessive movement spoiled killed lift volved wing panel Conclusions Dont use too much movement because narrow strip limitations widen ailerons use less movement forget differential un less have barndoor aileron suf ficient aileron chord workable modest movements probably symmetrical semi-symmetrical airfoils Differential does help down-aileron yawbut sign inadequate vertical area Almost dark railbirds didnt want go home Leaving asked disbe lief see no sleeping bags replied guys actually sit until after dark feeling good aight told full moon came up fliers being what guy offered another plane shoot go-rounds moonlight approach cloud hid moon guy still got Full moon Eloy Marez writes four-cycles MAN well indeed urges En joy upcoming building season unfor tunately dont get %$c&&c!* Au Thats direct quote forced fly year long heart bleeds all-year guys gotta build too An October day takes make yearin Land Oz Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 35 load testing glow battery starter battery complete test kit Other ideas Ive mentioned few uses Accu-Tach 2 little effort can find others item might offer some difficulty will figuring out measure resistance ohms Unfortunately wont find simple way meters sensitivity too low therefore currents would have put through item under test would destructive unless want build some kind external power supply amplifier decade switch time get done will have spent price pretty good VOM So King VOM hangs onto portion realm Accu-Tach 2 comes clip leads have make own used General Radio GR twin banana plugs Continued page 130 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro %Lubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc5%Castor Oil$775$695$675$650 4-cycle70/0Castor/Syn$850$765$750$725 4-cycle15%Castor/Syn$995$895$850$825 lOs100/0Synthetic$895$795$750$725 lOc10%Castor Oil$895$795$750$725 R/G12%Syn/Castor$995$895$850$825 iSs15%Synthetic$995$895$850$825 20c200/0Castor Oil$1395$1250$1200$1150 25s25%Synthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 505Q0/iSynthetic$2395$2100$2050$2000 60600/oSynthetic$2695$2400$2300$2200 IN CONTINENTAL USA SHELDONSHours M/C VISAHOBBY SHOPMon Wed Fn&Sat 930 530 3157 Alum Rock AvenueThur 930-900 24-124 Gal shipped via truckSan Jose California 95127Sun 1200-500 UPSCOD-Sl65 408 251-0787 TEE PIlE IS EIGHT So spend extra money spots will last least 2 wated time r flIed years after purchase tires Flat spots poor unconditIonally durability problem wth wheels9 Wth D Marcovecch 0 Available 7/2 & 8 sizes vintage II get wheel military styles Smooth guaranteed develop flat embossed spoked covers available 0For compieie brochure send $1 io D Maivovecchio welcome dealer inquires PER PAIR PO Box 37 ingviiie 11738 February 1985127 Price 2995 I- V_______________ Miter Master Mite Mast, tool designed enable crafts man make perfect joints wood accurately sanding pre-setangles TlresquaringfencejAj allomsforprecisegO angles retracts below surface Any angle can beset triangular guide using adjacent side complement angle mill funned making invaluable truss construction new cyanoacrylate adhesives require accurately fitted joints achieve fulf strength Miter Master mill enable make theni easrly FOURMOST PRODUCTS 4040 24th Ave Forest Grove OR 97116 Radio Technique/Myers Continued page 127 some patch cords salvaged old piece test gear being discarded might have buy somewhere Radio Shack offers several options cluding GR plugs thats no problem prefer unit has wire stand back case holds con venient viewing angle made characteristic Accu-Tach 2 dont like its long settling time uses five seconds reach its final reading accustomed instantaneous response dArsenval meter five seconds seems like very long time other hand delay really isnt critical unless trying trap some transient phenomenon trying probably should using oscilloscope strip-chart recorder Till meet again George M Myers 70 Froehlich Farm Rd. Hicksville NY 11801 friendly Price $950 Assemsleo booed 503 357-2732 AMA Frequency Committee Chairman PS know friendly District Frequency Coordinator Are having interference problems Tell him DFC about 0MM Glitch Buster/Utasi Continued page 38 little bit better noise immunity especial ly metal-to- ictal noise Thats see Helicopter pilots using FM AM fine too What dont see discussed anywhere AM receiver design has less noise front-end circuitry Most certainly new narrow-band designs first-rate offer good selectivity sensitivity around good performance Trouble someone frequency turns its over tears FM really lucky might just get someone turns antenna down signal still keeps receiver captured seems Im never lucky Maybe luck better us can afford PCM system Contrary popular belief someone frequency turns will still crash likely difference crash interference weak inter mittent system may able read between lines maintain con trol although response may seem slow sluggish interference serious constant receiver may go fail-safe mode servos move predetermined position flying Buzzard Bombshell some other Old-Timer may fine youre flying 30-lb ship 5 hp neutral stability Id head cover way pay money take chances could afford Id fly PCM about different glitch stop gadgets available Basically devices consist signal buffers made logic device called buffer inverter boosts signal strength servo presents noise signal line getting back decoder cases devices trick unless have serious problem Another good item helps solve problems system allows use separate battery packs powering receiver servos RAM has such product market goes long way toward cleaning up lots problems created long leads noisy servo motors cases switching sepa rate battery packs receiver ser vos will completely eradicate glitch problems Its little extra wiring re quires some extra patience results well worth Finally get hear something really new After spending about two days phone long distance calls uncovered new theory about long leads glitches comes long-time RF expert has designed some popu lar radios around today seems days receiver designs use what re ferred single-ended front end Continued page 132 Specifications Wing Area 1500 sq Span 7-2 Weight 20-25 lbs Engine 20-37 Fuselage Formers/Planking Wing Foam 3/32 Sheeting Stab Fin Solid Sheet Clear Canopy/All Balsa Major Decals Included Kit I99~ Sure winner ScaleOH Residents add 6 % tan Send $100 complete catalogueVideo Tapes 0-130 B-29 also available VHS BETA $2995 RIO Mfg 706 Easton NE North Canton OH 44721 216-499-5323 130Model Aviation NEW FOURMOST PRODUCTS FUSELAGE FIXTURE FOURMOST FUSELAGE FIXTURE designed Aadeantically align fuselage structures built strings measuring eveballing Simply slide tour centering brackets track until align firewall tail joint two bulkheads Clamp hselagetogetherlightly mith rubberbands structure will straight track New 1/5 Scale Sea Fury Beautiful Stable Flyer Capable AllAerobatlc C Yes invited So joIn National Soaring Society OFFICIAL SOARING SPECIAL INTERFET GROUP YEARLY NATIONAL TOURNAMENTS NATION-WIDE EXCELLENCE AWARDS PRoGRAM C EXCELLENT al-MONTHLY NEWSLETTER NSS CONTRIBUTES SUBSTANTIAL AMOUNTS TO EACH F3B SOARING TEAM NES IS RESPONSIBLE FOR THE ORGANIZATION AND OVERSEEING OF AMA NATS INCLUDING AWARDS BANOUET YEARLY DUES ARE $1200 ISPECIAL FAMILY RATES NSS OFFICERS ARE FROM ALL 11 DISTRICTS lor Information Contscts JOHN R VOGEL 90k ORCHARD PARK DR GISSONIA PA 15044
Edition: Model Aviation - 1985/02
Page Numbers: 34, 35, 127, 130
Radio Technique George M Myers USEFUL TOOLS long have playing things electronic VOM AC/DC Volt-Ohm Meter has reigned king electronic tools. ntial tool Occa sionally needs specialized tools like oscilloscope bench power supply servo cycler battery tester digital pulse meter etc can still accomplish useful things have VOM skill use Now am about describe VAT Volt/Amp/Tachometer first tool offered RC use presents serious challenge supremacy VOM subject Accu-Tach 2 Nor Cal Avionics Inc PO Box 70956 Sunnyvale CA 94088 Accu-Tach 2 combines digital DC centivoltmeter DC milliammeter optical tachom eter handy package will fit neatly anybodys field box life Ive farsighted great seeing model distance good reading telephone book Accu-Tach 2 LCD display uses big x A-inch numbers display values between plus minus 1999 can read glasses am grateful hate wear anything safety sun glasses Perhaps will find easy read also permissible viewing angle good numbers can read 450 off perpendicular directions Accu-Tach 2 will following 1 Measure DC battery Voltage range thru 1999 centi-volts call 0 VDC shunting circuit under test 600K ohms resis tance large enough minimize circuit loading Accu-Tach 2 can used poking around inside receivers volt age range fine aligning receivers well diagnosing troubles kinds likely encountered transmitters receivers servos battery packs 2 Measure rpm range 10 35000 rpm optically No dangerous contact rotating machinery necessary range adequate gasoline- alcohol-fueled engines whether idle maximum rpm well electric motors such used power model airplanes tachom eter will satisfy needs customary sport competition models ducted fans helicopters etc 3 Measure DC current range /- 1 thru 1999 mA call /- 2 amps range nicely fits kinds RC uses such measuring charging cur rents measuring discharge currents typical transmitters servos full RC systems 4 Measure battery pack voltage under load nominal 200 mA Again range volts minimum indication 10 mV So much capabilities now lets look some applications Tachometer Push switch left side case towards tachometer eye top case point eye towards whirling propeller keeping six-inch clearance read rpm Two measuring ranges provided rpm/l0 rpm/100 counter works 70000 pulses per minute good 35000 rpm two-bladed propeller display-scaling circuitry set up use two-bladed propeller Point two-bladed prop read correct rpm range 10 35000 rpm divided either 10 100 depending front-panel switch position chose using single-bladed prop multiply number indicated factor 2 prop has three blades multi ply indicated number % prop has four blades multiply indica tion etc As can see case multiplier found using two divided number blades Its little fussy about propeller il luminated point lens Ive always able find some position will read properly Milliammeter panel marked Amps meter indicates directly milliamps range interest RCers measuring voltage drop across meter current running through calculated series insertion 105 ohms /- 5% ammeter limited maximum two amps because internal cir cuitry set up way because display limited 1999 counts ICs notoriously intolerant overloads Bob Aberles suggestion made red lead fused ammeter lead insert ing Radio Shack Inline Mini Fuse Holder No 270-1238 used two-amp fuse No 270-1244 increases inser tion resistance about 45 ohms may too much some tests its handy Ive already blown couple fuses Accu-Tach 2 still works must good idea Thanks Bob As example its use Accu-Tach 2 indicated 680 mA MEN C/50-4 34Model Aviation Accu-Tach 2 wIth hIgh-current ada p tsr fused test lead common lead George tells us get good usage out thIs versatile instrumentfor better RC flying charger pumping up SR900 bat tery pack High Rate 41 mA chargers LED went out very close what iron-vane ammeter reads should able measure charg ing current used RC equipment Making use idea presented RT back October 1979 Accu Tach 2 handbook suggests used evaluate RC system installation Since everyone should make such evalua tions since device makes doing convenient Ill go over proce dure again need cut battery lead aileron-extender cable connect cut ends milliammeter like Accu-Tach 2 Put adapter tween flight pack switch harness Turn transmitter receiver observe current being drawn try control its extreme position trim available same extreme can stall servo position will see amps jump way up stay up warning reset throttle stop clear epoxy out hinges make additional clearance pushrods etc can put modified aileron extender-cable between servo receiver evaluate particular servo installation problems may work system installation stability margin setup low enough insertion resistance Accu-Tach 2 oscilla tor strobes display may drive system instability Centivoitmeter meter indicates centivolts what else would call meter shows cV battery pack has terminal voltage Volts Id happier front panel marked cV instead Volts Either automatic decimal point should have provided decimal point moves around lot machine Ive already mentioned some customary voltmeter uses above Heres another Since Accu-Tach 2 indicates numbers small 10 mV same i cv can use peak-detection charging hurry set up charging rate will get job done 15 minutes mom tor battery terminal voltage see voltage drop 2 cV below what few seconds before charging complete must caution overcharging high rate can ruin battery must pay attention what doing should battery pack cool touch pack will get quite warm during charging should never get hot gets hot stays hot know youve just junked battery pack Now heres equipment mix TACHOMETER : _____________________________________ VOLT/AMP ACCU-TAcH2 METER Rx p Tx Corn 1999 CENTI VOLTS DC 1999M1LL1-N AMPS DC HIGH-CURRENT * ADAPTER FOR ESV ESV COMMON LEAD FOR ALL MEASUREMENTS TX& RPM/b I-i I] RXEI RPM/100 Heres what switches Inputs AccuTach 2 match crowd can measure control pulses coming out receiver deter positive- negative-going can determine whether use some substitute servos Connect Com mon lead battery Negative Connect Positive Volts lead signal lead coming out receiver Push common pin thru servo pigtail necessary Now voltage shows about 25 cV looking positive-going pulses reads about 380 cV have negative-going pulses very rare ESV expanded-scale voltmeter some built-in loading resistors switch-selected transmitter 60 ohms flight pack 30 ohms cause nominal drain 167 mA adequate compromise test majori ty RC equipment Loaded way Accu-Tach 2 can expect good fully-charged pack discharged about three hours An adapter offered loading large packs 48 6 VDC 900 mAh up 417 mA ESV test consists 20 ohm/S watt resistor GR plug plug adapter Accu-Tach 2 plug test leads adapter 417 mA drain representative large-servo service conditions get realistic test larger packs adapter As Bob Aberle pointed out should remember adapter plugs same sockets used transmitter testing just flip switch Accu-Tach 2 front panel However wouldnt want use adapter testing 10- 12-volt transmitter pack 12-volt starter battery because adapter will draw excessive current transmitter pack loading resistor will get very hot stink Guess know can use Accu-Tach 2 kinds battery testing needing clock pencil paper some kind Continued page 127 TO TO AMP COM OR BATTE 3ZL can make systemlammeter test cable aileron extension cable Use test overloads servos general health RC system etc February 198535 I V med Just try Thats grabbed transmitter Don fly wing land feet needed funny mushrooms about must answer guys tried help RTF dropped wing badly up aileron Only Ken Willard provided faint clue answer plane heavy flyable Ailerons narrow strip differentialmore up down high loadings angle narrow up-aileron excessive movement spoiled killed lift volved wing panel Conclusions Dont use too much movement because narrow strip limitations widen ailerons use less movement forget differential un less have barndoor aileron suf ficient aileron chord workable modest movements probably symmetrical semi-symmetrical airfoils Differential does help down-aileron yawbut sign inadequate vertical area Almost dark railbirds didnt want go home Leaving asked disbe lief see no sleeping bags replied guys actually sit until after dark feeling good aight told full moon came up fliers being what guy offered another plane shoot go-rounds moonlight approach cloud hid moon guy still got Full moon Eloy Marez writes four-cycles MAN well indeed urges En joy upcoming building season unfor tunately dont get %$c&&c!* Au Thats direct quote forced fly year long heart bleeds all-year guys gotta build too An October day takes make yearin Land Oz Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 35 load testing glow battery starter battery complete test kit Other ideas Ive mentioned few uses Accu-Tach 2 little effort can find others item might offer some difficulty will figuring out measure resistance ohms Unfortunately wont find simple way meters sensitivity too low therefore currents would have put through item under test would destructive unless want build some kind external power supply amplifier decade switch time get done will have spent price pretty good VOM So King VOM hangs onto portion realm Accu-Tach 2 comes clip leads have make own used General Radio GR twin banana plugs Continued page 130 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro %Lubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc5%Castor Oil$775$695$675$650 4-cycle70/0Castor/Syn$850$765$750$725 4-cycle15%Castor/Syn$995$895$850$825 lOs100/0Synthetic$895$795$750$725 lOc10%Castor Oil$895$795$750$725 R/G12%Syn/Castor$995$895$850$825 iSs15%Synthetic$995$895$850$825 20c200/0Castor Oil$1395$1250$1200$1150 25s25%Synthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 505Q0/iSynthetic$2395$2100$2050$2000 60600/oSynthetic$2695$2400$2300$2200 IN CONTINENTAL USA SHELDONSHours M/C VISAHOBBY SHOPMon Wed Fn&Sat 930 530 3157 Alum Rock AvenueThur 930-900 24-124 Gal shipped via truckSan Jose California 95127Sun 1200-500 UPSCOD-Sl65 408 251-0787 TEE PIlE IS EIGHT So spend extra money spots will last least 2 wated time r flIed years after purchase tires Flat spots poor unconditIonally durability problem wth wheels9 Wth D Marcovecch 0 Available 7/2 & 8 sizes vintage II get wheel military styles Smooth guaranteed develop flat embossed spoked covers available 0For compieie brochure send $1 io D Maivovecchio welcome dealer inquires PER PAIR PO Box 37 ingviiie 11738 February 1985127 Price 2995 I- V_______________ Miter Master Mite Mast, tool designed enable crafts man make perfect joints wood accurately sanding pre-setangles TlresquaringfencejAj allomsforprecisegO angles retracts below surface Any angle can beset triangular guide using adjacent side complement angle mill funned making invaluable truss construction new cyanoacrylate adhesives require accurately fitted joints achieve fulf strength Miter Master mill enable make theni easrly FOURMOST PRODUCTS 4040 24th Ave Forest Grove OR 97116 Radio Technique/Myers Continued page 127 some patch cords salvaged old piece test gear being discarded might have buy somewhere Radio Shack offers several options cluding GR plugs thats no problem prefer unit has wire stand back case holds con venient viewing angle made characteristic Accu-Tach 2 dont like its long settling time uses five seconds reach its final reading accustomed instantaneous response dArsenval meter five seconds seems like very long time other hand delay really isnt critical unless trying trap some transient phenomenon trying probably should using oscilloscope strip-chart recorder Till meet again George M Myers 70 Froehlich Farm Rd. Hicksville NY 11801 friendly Price $950 Assemsleo booed 503 357-2732 AMA Frequency Committee Chairman PS know friendly District Frequency Coordinator Are having interference problems Tell him DFC about 0MM Glitch Buster/Utasi Continued page 38 little bit better noise immunity especial ly metal-to- ictal noise Thats see Helicopter pilots using FM AM fine too What dont see discussed anywhere AM receiver design has less noise front-end circuitry Most certainly new narrow-band designs first-rate offer good selectivity sensitivity around good performance Trouble someone frequency turns its over tears FM really lucky might just get someone turns antenna down signal still keeps receiver captured seems Im never lucky Maybe luck better us can afford PCM system Contrary popular belief someone frequency turns will still crash likely difference crash interference weak inter mittent system may able read between lines maintain con trol although response may seem slow sluggish interference serious constant receiver may go fail-safe mode servos move predetermined position flying Buzzard Bombshell some other Old-Timer may fine youre flying 30-lb ship 5 hp neutral stability Id head cover way pay money take chances could afford Id fly PCM about different glitch stop gadgets available Basically devices consist signal buffers made logic device called buffer inverter boosts signal strength servo presents noise signal line getting back decoder cases devices trick unless have serious problem Another good item helps solve problems system allows use separate battery packs powering receiver servos RAM has such product market goes long way toward cleaning up lots problems created long leads noisy servo motors cases switching sepa rate battery packs receiver ser vos will completely eradicate glitch problems Its little extra wiring re quires some extra patience results well worth Finally get hear something really new After spending about two days phone long distance calls uncovered new theory about long leads glitches comes long-time RF expert has designed some popu lar radios around today seems days receiver designs use what re ferred single-ended front end Continued page 132 Specifications Wing Area 1500 sq Span 7-2 Weight 20-25 lbs Engine 20-37 Fuselage Formers/Planking Wing Foam 3/32 Sheeting Stab Fin Solid Sheet Clear Canopy/All Balsa Major Decals Included Kit I99~ Sure winner ScaleOH Residents add 6 % tan Send $100 complete catalogueVideo Tapes 0-130 B-29 also available VHS BETA $2995 RIO Mfg 706 Easton NE North Canton OH 44721 216-499-5323 130Model Aviation NEW FOURMOST PRODUCTS FUSELAGE FIXTURE FOURMOST FUSELAGE FIXTURE designed Aadeantically align fuselage structures built strings measuring eveballing Simply slide tour centering brackets track until align firewall tail joint two bulkheads Clamp hselagetogetherlightly mith rubberbands structure will straight track New 1/5 Scale Sea Fury Beautiful Stable Flyer Capable AllAerobatlc C Yes invited So joIn National Soaring Society OFFICIAL SOARING SPECIAL INTERFET GROUP YEARLY NATIONAL TOURNAMENTS NATION-WIDE EXCELLENCE AWARDS PRoGRAM C EXCELLENT al-MONTHLY NEWSLETTER NSS CONTRIBUTES SUBSTANTIAL AMOUNTS TO EACH F3B SOARING TEAM NES IS RESPONSIBLE FOR THE ORGANIZATION AND OVERSEEING OF AMA NATS INCLUDING AWARDS BANOUET YEARLY DUES ARE $1200 ISPECIAL FAMILY RATES NSS OFFICERS ARE FROM ALL 11 DISTRICTS lor Information Contscts JOHN R VOGEL 90k ORCHARD PARK DR GISSONIA PA 15044
Edition: Model Aviation - 1985/02
Page Numbers: 34, 35, 127, 130
Radio Technique George M Myers USEFUL TOOLS long have playing things electronic VOM AC/DC Volt-Ohm Meter has reigned king electronic tools. ntial tool Occa sionally needs specialized tools like oscilloscope bench power supply servo cycler battery tester digital pulse meter etc can still accomplish useful things have VOM skill use Now am about describe VAT Volt/Amp/Tachometer first tool offered RC use presents serious challenge supremacy VOM subject Accu-Tach 2 Nor Cal Avionics Inc PO Box 70956 Sunnyvale CA 94088 Accu-Tach 2 combines digital DC centivoltmeter DC milliammeter optical tachom eter handy package will fit neatly anybodys field box life Ive farsighted great seeing model distance good reading telephone book Accu-Tach 2 LCD display uses big x A-inch numbers display values between plus minus 1999 can read glasses am grateful hate wear anything safety sun glasses Perhaps will find easy read also permissible viewing angle good numbers can read 450 off perpendicular directions Accu-Tach 2 will following 1 Measure DC battery Voltage range thru 1999 centi-volts call 0 VDC shunting circuit under test 600K ohms resis tance large enough minimize circuit loading Accu-Tach 2 can used poking around inside receivers volt age range fine aligning receivers well diagnosing troubles kinds likely encountered transmitters receivers servos battery packs 2 Measure rpm range 10 35000 rpm optically No dangerous contact rotating machinery necessary range adequate gasoline- alcohol-fueled engines whether idle maximum rpm well electric motors such used power model airplanes tachom eter will satisfy needs customary sport competition models ducted fans helicopters etc 3 Measure DC current range /- 1 thru 1999 mA call /- 2 amps range nicely fits kinds RC uses such measuring charging cur rents measuring discharge currents typical transmitters servos full RC systems 4 Measure battery pack voltage under load nominal 200 mA Again range volts minimum indication 10 mV So much capabilities now lets look some applications Tachometer Push switch left side case towards tachometer eye top case point eye towards whirling propeller keeping six-inch clearance read rpm Two measuring ranges provided rpm/l0 rpm/100 counter works 70000 pulses per minute good 35000 rpm two-bladed propeller display-scaling circuitry set up use two-bladed propeller Point two-bladed prop read correct rpm range 10 35000 rpm divided either 10 100 depending front-panel switch position chose using single-bladed prop multiply number indicated factor 2 prop has three blades multi ply indicated number % prop has four blades multiply indica tion etc As can see case multiplier found using two divided number blades Its little fussy about propeller il luminated point lens Ive always able find some position will read properly Milliammeter panel marked Amps meter indicates directly milliamps range interest RCers measuring voltage drop across meter current running through calculated series insertion 105 ohms /- 5% ammeter limited maximum two amps because internal cir cuitry set up way because display limited 1999 counts ICs notoriously intolerant overloads Bob Aberles suggestion made red lead fused ammeter lead insert ing Radio Shack Inline Mini Fuse Holder No 270-1238 used two-amp fuse No 270-1244 increases inser tion resistance about 45 ohms may too much some tests its handy Ive already blown couple fuses Accu-Tach 2 still works must good idea Thanks Bob As example its use Accu-Tach 2 indicated 680 mA MEN C/50-4 34Model Aviation Accu-Tach 2 wIth hIgh-current ada p tsr fused test lead common lead George tells us get good usage out thIs versatile instrumentfor better RC flying charger pumping up SR900 bat tery pack High Rate 41 mA chargers LED went out very close what iron-vane ammeter reads should able measure charg ing current used RC equipment Making use idea presented RT back October 1979 Accu Tach 2 handbook suggests used evaluate RC system installation Since everyone should make such evalua tions since device makes doing convenient Ill go over proce dure again need cut battery lead aileron-extender cable connect cut ends milliammeter like Accu-Tach 2 Put adapter tween flight pack switch harness Turn transmitter receiver observe current being drawn try control its extreme position trim available same extreme can stall servo position will see amps jump way up stay up warning reset throttle stop clear epoxy out hinges make additional clearance pushrods etc can put modified aileron extender-cable between servo receiver evaluate particular servo installation problems may work system installation stability margin setup low enough insertion resistance Accu-Tach 2 oscilla tor strobes display may drive system instability Centivoitmeter meter indicates centivolts what else would call meter shows cV battery pack has terminal voltage Volts Id happier front panel marked cV instead Volts Either automatic decimal point should have provided decimal point moves around lot machine Ive already mentioned some customary voltmeter uses above Heres another Since Accu-Tach 2 indicates numbers small 10 mV same i cv can use peak-detection charging hurry set up charging rate will get job done 15 minutes mom tor battery terminal voltage see voltage drop 2 cV below what few seconds before charging complete must caution overcharging high rate can ruin battery must pay attention what doing should battery pack cool touch pack will get quite warm during charging should never get hot gets hot stays hot know youve just junked battery pack Now heres equipment mix TACHOMETER : _____________________________________ VOLT/AMP ACCU-TAcH2 METER Rx p Tx Corn 1999 CENTI VOLTS DC 1999M1LL1-N AMPS DC HIGH-CURRENT * ADAPTER FOR ESV ESV COMMON LEAD FOR ALL MEASUREMENTS TX& RPM/b I-i I] RXEI RPM/100 Heres what switches Inputs AccuTach 2 match crowd can measure control pulses coming out receiver deter positive- negative-going can determine whether use some substitute servos Connect Com mon lead battery Negative Connect Positive Volts lead signal lead coming out receiver Push common pin thru servo pigtail necessary Now voltage shows about 25 cV looking positive-going pulses reads about 380 cV have negative-going pulses very rare ESV expanded-scale voltmeter some built-in loading resistors switch-selected transmitter 60 ohms flight pack 30 ohms cause nominal drain 167 mA adequate compromise test majori ty RC equipment Loaded way Accu-Tach 2 can expect good fully-charged pack discharged about three hours An adapter offered loading large packs 48 6 VDC 900 mAh up 417 mA ESV test consists 20 ohm/S watt resistor GR plug plug adapter Accu-Tach 2 plug test leads adapter 417 mA drain representative large-servo service conditions get realistic test larger packs adapter As Bob Aberle pointed out should remember adapter plugs same sockets used transmitter testing just flip switch Accu-Tach 2 front panel However wouldnt want use adapter testing 10- 12-volt transmitter pack 12-volt starter battery because adapter will draw excessive current transmitter pack loading resistor will get very hot stink Guess know can use Accu-Tach 2 kinds battery testing needing clock pencil paper some kind Continued page 127 TO TO AMP COM OR BATTE 3ZL can make systemlammeter test cable aileron extension cable Use test overloads servos general health RC system etc February 198535 I V med Just try Thats grabbed transmitter Don fly wing land feet needed funny mushrooms about must answer guys tried help RTF dropped wing badly up aileron Only Ken Willard provided faint clue answer plane heavy flyable Ailerons narrow strip differentialmore up down high loadings angle narrow up-aileron excessive movement spoiled killed lift volved wing panel Conclusions Dont use too much movement because narrow strip limitations widen ailerons use less movement forget differential un less have barndoor aileron suf ficient aileron chord workable modest movements probably symmetrical semi-symmetrical airfoils Differential does help down-aileron yawbut sign inadequate vertical area Almost dark railbirds didnt want go home Leaving asked disbe lief see no sleeping bags replied guys actually sit until after dark feeling good aight told full moon came up fliers being what guy offered another plane shoot go-rounds moonlight approach cloud hid moon guy still got Full moon Eloy Marez writes four-cycles MAN well indeed urges En joy upcoming building season unfor tunately dont get %$c&&c!* Au Thats direct quote forced fly year long heart bleeds all-year guys gotta build too An October day takes make yearin Land Oz Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 35 load testing glow battery starter battery complete test kit Other ideas Ive mentioned few uses Accu-Tach 2 little effort can find others item might offer some difficulty will figuring out measure resistance ohms Unfortunately wont find simple way meters sensitivity too low therefore currents would have put through item under test would destructive unless want build some kind external power supply amplifier decade switch time get done will have spent price pretty good VOM So King VOM hangs onto portion realm Accu-Tach 2 comes clip leads have make own used General Radio GR twin banana plugs Continued page 130 High film strength lubricant increased power long engine life Detergents cut performance robbing varnish Highest quality ingredients insure top engine performance reliability Anti-foam additives prevent high RPM lean out Rust preventatives protect expensive engines TypeNitro %Lubricant4 Gal24 Gal64 Gal124 Gal FAI0%Synthetic$675$595$575$550 5s50/0Synthetic$775$695$675$650 Sc5%Castor Oil$775$695$675$650 4-cycle70/0Castor/Syn$850$765$750$725 4-cycle15%Castor/Syn$995$895$850$825 lOs100/0Synthetic$895$795$750$725 lOc10%Castor Oil$895$795$750$725 R/G12%Syn/Castor$995$895$850$825 iSs15%Synthetic$995$895$850$825 20c200/0Castor Oil$1395$1250$1200$1150 25s25%Synthetic$1495$1350$1300$1250 4040%15 Syn-5 Castor$1995$1795$1750$1700 505Q0/iSynthetic$2395$2100$2050$2000 60600/oSynthetic$2695$2400$2300$2200 IN CONTINENTAL USA SHELDONSHours M/C VISAHOBBY SHOPMon Wed Fn&Sat 930 530 3157 Alum Rock AvenueThur 930-900 24-124 Gal shipped via truckSan Jose California 95127Sun 1200-500 UPSCOD-Sl65 408 251-0787 TEE PIlE IS EIGHT So spend extra money spots will last least 2 wated time r flIed years after purchase tires Flat spots poor unconditIonally durability problem wth wheels9 Wth D Marcovecch 0 Available 7/2 & 8 sizes vintage II get wheel military styles Smooth guaranteed develop flat embossed spoked covers available 0For compieie brochure send $1 io D Maivovecchio welcome dealer inquires PER PAIR PO Box 37 ingviiie 11738 February 1985127 Price 2995 I- V_______________ Miter Master Mite Mast, tool designed enable crafts man make perfect joints wood accurately sanding pre-setangles TlresquaringfencejAj allomsforprecisegO angles retracts below surface Any angle can beset triangular guide using adjacent side complement angle mill funned making invaluable truss construction new cyanoacrylate adhesives require accurately fitted joints achieve fulf strength Miter Master mill enable make theni easrly FOURMOST PRODUCTS 4040 24th Ave Forest Grove OR 97116 Radio Technique/Myers Continued page 127 some patch cords salvaged old piece test gear being discarded might have buy somewhere Radio Shack offers several options cluding GR plugs thats no problem prefer unit has wire stand back case holds con venient viewing angle made characteristic Accu-Tach 2 dont like its long settling time uses five seconds reach its final reading accustomed instantaneous response dArsenval meter five seconds seems like very long time other hand delay really isnt critical unless trying trap some transient phenomenon trying probably should using oscilloscope strip-chart recorder Till meet again George M Myers 70 Froehlich Farm Rd. Hicksville NY 11801 friendly Price $950 Assemsleo booed 503 357-2732 AMA Frequency Committee Chairman PS know friendly District Frequency Coordinator Are having interference problems Tell him DFC about 0MM Glitch Buster/Utasi Continued page 38 little bit better noise immunity especial ly metal-to- ictal noise Thats see Helicopter pilots using FM AM fine too What dont see discussed anywhere AM receiver design has less noise front-end circuitry Most certainly new narrow-band designs first-rate offer good selectivity sensitivity around good performance Trouble someone frequency turns its over tears FM really lucky might just get someone turns antenna down signal still keeps receiver captured seems Im never lucky Maybe luck better us can afford PCM system Contrary popular belief someone frequency turns will still crash likely difference crash interference weak inter mittent system may able read between lines maintain con trol although response may seem slow sluggish interference serious constant receiver may go fail-safe mode servos move predetermined position flying Buzzard Bombshell some other Old-Timer may fine youre flying 30-lb ship 5 hp neutral stability Id head cover way pay money take chances could afford Id fly PCM about different glitch stop gadgets available Basically devices consist signal buffers made logic device called buffer inverter boosts signal strength servo presents noise signal line getting back decoder cases devices trick unless have serious problem Another good item helps solve problems system allows use separate battery packs powering receiver servos RAM has such product market goes long way toward cleaning up lots problems created long leads noisy servo motors cases switching sepa rate battery packs receiver ser vos will completely eradicate glitch problems Its little extra wiring re quires some extra patience results well worth Finally get hear something really new After spending about two days phone long distance calls uncovered new theory about long leads glitches comes long-time RF expert has designed some popu lar radios around today seems days receiver designs use what re ferred single-ended front end Continued page 132 Specifications Wing Area 1500 sq Span 7-2 Weight 20-25 lbs Engine 20-37 Fuselage Formers/Planking Wing Foam 3/32 Sheeting Stab Fin Solid Sheet Clear Canopy/All Balsa Major Decals Included Kit I99~ Sure winner ScaleOH Residents add 6 % tan Send $100 complete catalogueVideo Tapes 0-130 B-29 also available VHS BETA $2995 RIO Mfg 706 Easton NE North Canton OH 44721 216-499-5323 130Model Aviation NEW FOURMOST PRODUCTS FUSELAGE FIXTURE FOURMOST FUSELAGE FIXTURE designed Aadeantically align fuselage structures built strings measuring eveballing Simply slide tour centering brackets track until align firewall tail joint two bulkheads Clamp hselagetogetherlightly mith rubberbands structure will straight track New 1/5 Scale Sea Fury Beautiful Stable Flyer Capable AllAerobatlc C Yes invited So joIn National Soaring Society OFFICIAL SOARING SPECIAL INTERFET GROUP YEARLY NATIONAL TOURNAMENTS NATION-WIDE EXCELLENCE AWARDS PRoGRAM C EXCELLENT al-MONTHLY NEWSLETTER NSS CONTRIBUTES SUBSTANTIAL AMOUNTS TO EACH F3B SOARING TEAM NES IS RESPONSIBLE FOR THE ORGANIZATION AND OVERSEEING OF AMA NATS INCLUDING AWARDS BANOUET YEARLY DUES ARE $1200 ISPECIAL FAMILY RATES NSS OFFICERS ARE FROM ALL 11 DISTRICTS lor Information Contscts JOHN R VOGEL 90k ORCHARD PARK DR GISSONIA PA 15044