G eorg eM Myers QUESTION OF THE DAY improve interference resistance Some people believe have inter ference today 10 years ago Well wrong actually have lot less interference before also have people trying use fewer flying fields pushes us closer together makes modelerto-modeler interference noticeable Ten years ago seven RC channels 72 75 MHz Four assigned Aircraft Only three shared cars boats channels shared other services Given todays explosion interest RC cars boats kinds what sort interference suppose wed have old situation continued significantly has tremen dous increase non-hobby users numbered frequencies 72080 72240 etc must share until 1988 fundamental issue petition FCC new channels concept sharing made ridiculous permitted 300-watt transmitters antennas located 1000 feet above ground restricted hand-held -wave whip antenna FCC listened argument agreed got bonanza AMA critics ignore facts 1 FCC gave us exclusive use new odd-frequency channels 7201 thru 7299 MHz still have exclusivity means non-hobby RC user excluded hobby transmitters new RC channels must radiate approximately same level power similar antennas situation defines less interference 2 AMA gave us Phase-In Plan created controlled environment contin ued use existing equipment protected market improved equipment provided Phase-In Plan prevented kinds interference would have occurred moved immediately old channels spaced 80 kHz new ones spaced 20 kHz 3 place interference-resistance hasnt changed much 31M third-order intermodulation What have now what before channels chose have opportunities 31M consequence uniform channel spacing Supporting bonanza Right begin ning knew some new channels would unusable also knew better receivers required take best advantage what given RC systems manufac turers jumped market created AMA Phase-In Plan packages offering features dreamed few years before might have done new RC channels Some new systems pretty bad Others very good good example lowpriced 1983 Tower Gold 500 transmitter part very early new system Yet passed AMA 1991 tests its plug-in crystals RCl2 RC4O RC5O RC56 Thats better performance anyone expected illustrates point satisfactory trans mitters easier obtain satisfactory receivers Some systems reached market period 1983-1986 worse receivers before vendors usually worked hard replace During same period some very advanced receivers also appeared now have PCM systems Kraft Channel Max synthesized-RF equipment although Kraft itself gone Just week tested prototype receiver shows best performance weve ever seen survives transition production will able buy medium-priced highperformance system transmitter receiver 1987 Reducing interference way careful chan nel selections Time again detractors delight reciting dont need 50 channels because theres no way can use 50 channels simultaneously Baloney could have used beginning worst yesterdays radios wed have break up 50 channels appropriate groups group used flying field keeping flying fields about mile apart observing frequency assignments carefully wouldnt have interference either 31M other kinds possible right now fly Pattern Pylon Scale Helicopters simultaneously same Nats site needed preassign ment RC channels Heres could done no 31M image airport 80kHz channel separation using number channels assigned airport restric tions combinations Pattern airport RCl2 17 21 28 32 37 41 47 51 56 60 Sailplane airport RC11 16 20273136 40 46 50 55 59 Pylon airport RCl5 19 26 30 35 39 4549 54 58 Helicopter airport RC14 182529343844 38 Model Aviation proToType error bwITCfl WlTfl TflO TWO z TOST receivers xnree servos ana DaTterles George started telling us about system last month Switch may stand out background too well larger rectangular object center Fiberglass arrow shafts support receiver antennas column 72240 M Hz slave transmitter simple Sufficient volume remains within mini-box house eight 450 mAh Ni-Cd batteries switch decide needs its own power supply belt-loop bent scrap metal pop-riveted place also receives wire stake ground-based installation desired Two Redundant Radio transmitters Myers Above uses Ace Silver Seven transmit ter slave transmitter worn belt Bob Aberles Below uses Custom Electronics T-Module customized AM Kraft synthesized RF module Slave trans mitter minimally annoying Remember collapse antenna before going through doorways modified buddy-box cable connects master going flying words conjure up images battles balky engines instead carefree days field youre using McDaniel RIC NiStarterTM light plug Ni-StartersTM heavy-duty nicad power will provide up 50 reliable quick starts charge features famous Head LockTM adapter brass reinforcing ring around crimped end really extends its life works sideways inverted information well NiStarter works just go local flying field may have wait NiStartersTM always flying McDaniel RIC Incorporated 12206 Guinevere Road Glenn Dale MD 20769 301/464-2260 Telex 287901 MeD-CR take hassle out hobby 48 53 57 have thank Owen S Black out Carmichael CA scheme produced assignments Owen first person know figured way avoid 31M keep 80-kHz minimum spacing accommo date continued use old radios get benefits have avoid using eight channels RCl3 22 23 24 33 42 43 52 somehow arrange specific RC channels used specific locations likely people will observe restrictions make safer Would competition fliers accept preassigned channels now essentially Would sport fliers select group preassigned frequencies airport observe restrictions voluntar ily likely talking self-discipline Thats AMA keeping pressure manufacturers come up radio systems dont need kind protec tion Most new systems work very well 20 kHz spacing best new receivers showing some improved 31M resistance Now lets look some facts life RC business 1 No matter good RC systems no matter carefully people observe above restrictions will still interference two people try use same frequency same time 2 When system have stops working plane out control Reducing interference means redun Continued page 129 October 1986 39 Consumers Guide Radio Control Products Its Listed THIRD Dont Need EDITION See hobby shop order direct $075 Price $785 plus $180 UPS total ign air mail *13458795 pIus $5 501 u 5 dollars please Send Check MO Credit Card info Consumers Guide 150 Ott St Harrisonburg VA 22S01 4340350 Name Address Charge Card No IMC VISA CHOICEl MasterCard B # ______________________ Expiration flnta SOMETHING NEW & BETTER! THE uii CWfWVTPf4 SPORT/TRAINER SIMPLE TO BUILD EASY TO FLY TRAINER -ORBUILD IT WITH AILERONS AND DO IT ALL OR WITH 05 ELECTRIC MOTOR 48 SPAN SQ IN 43 OZ SELECTED DIE AND MACHINE CUT BALSA AND PLYWOOD COMPLETE ROLLED PLANS STEP-BY-STEP INSTRUCTIONS ALL HARDWARE AND FORMED GEAR FLY WITH 20 FOUR CYCLE ENGINE ASK YOUR DEALER own back gust world dare say turns chases wind Turning wind effect creating gust-like environment head Its kinetic energy has converted something What really downwind turn way As Ken says downwind upwind has killed hundreds people can kill model go round float force bit dont bring up power youd expect strong wind Before war newly-soloed pilots some commercial guys 250 hours flew lightplanes over homesteads girl friends houses strong wind Theyd bank nicely wind gradually keep forcing circle rudder order see house gal simultaneously trying flatten angle bank ailerons cross controls theyd spin terrible mysterious problem until Leighton Collins explained great little magazine Air Facts As beginner wrote couple humble pieces him son editor Flying believe Argue among yourselves Dont bother pros cons share Willards comment Hey fellows lets knock off Just lets say some will lose altitude some wont will go out limb planes drift downwind Half-empty half-full glasses thats air oceanfor models anyway Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 39 simultaneously order get some protection guy turns checking other users channel same scheme simultaneous use two RC channels imple mented way two parallel independent operating systems can also protect us disastrous consequences simple failures like battery exhaustion having battery antenna wire break pretty common occur rences Calvin Orr Custom Electronics recently loaned prototype Error Switch Normally Calvin supports simultaneous use two different bands such 50MHz 72 MHz goal investigate simultaneous use two 72 MHz frequencies Calvin says simultaneous use two 72 MHz channels including Error Detector switch ing can performed today minor modifications presently-available equipment already done Airtronics AM equipment using modified buddy-box connec tion Stage 2 tests Error Switch loaned came equipped 19 Airtronics connectors cheap way todays prices can buy two complete systems simply add Error Switch modified buddy-box cable join complete Redundant Radio system outlay $500 About Error Switch airborne Error Switch $149 item comes two flavors AM FM prototype AM type Error Switch samples both receiver outputs shuts down whichever receiver suffering inter ference FM version has bit sophisti cated order take care FMs capture Continued page 132 NEW FOX 4CycIe Special MIRACLE GLOW PLUG totally new concept glow plug design Instead using idle bar MIRACLE PLUG built pre-cotubustion chanther important thing plug retains heat better other know Try . 4-cycle motor 2-cycle motor also will get smoother throttle reslonse lrolably will able use less exlensive low nitro fuel Tests also show reduced fuel consumption cases WARNING motor Irobably will idle faster reset throttle erwise might able land Hard believe . course check out MIRACLE PLUG Just case 40702 4-Cycle Glow Plug $275 Manufacturing Company 5305 Towson Avenue Fort Smith AR 72901 October 1986 129 I DAVEY EMS CORPORATION E WOOD LANE MALVERN PA 19355 215 644-6772 dant-channel usage should able use two RC channels AERO-PACER $8900 Span 64 1/2 Weight 55 7 lbs Engine 45 61 FS 5 TS ig 25 oz wing loading 4 channel Sport Trainer GIPSY $10900 MOTH Span 543/4 5475 Weight 5-6 lbs 787 sq inches 15 oz wing loading Engine 45 65 FS 0 TS 4 channel Both kits designed primarily Four-Stoke engine fly equally well Two-Stroke engine Add $450 shipping handling Direct SalesMichigan residents add 4B/0 sales tax Check money orderMastercard Visa Radio Techniq ue/MyersPropellers/Abbott Continued page 129Continued page 43 ratio problems Capture ratio refers characteristic FM receivers allows switch allegiance strongest transmitter vicinity FM Redundant Radio system possible rare possible someone operating vicinity channel take control airplane signal stronger receiver signal flying Redundant Radio system gain freedom interference having half system captured foreign transmitter doesnt help FM Error Switch has deal possibility tests Using oscilloscope set up Error Switch transmitter instructed ran few tests 1 The two receivers attached Error Switch attached via Red port Green port An LED light-emitting diode center device indicates system source signals being used control servo both transmitters working Green 72790 MHzRC5O Red old 72240 MHz servo worked normally Error Switch usually showed Green system control 2 When turned off Green transmitter LED indicated Red system 72240 MHz use servo acted normally 3 When turned off Red transmitter LED indicated Green system use servo acted normally 4 When turned off both transmitters LED indicated Red system select ed course servo did nothing 5 With both transmitters operating turned another RC5O Green transmitter LED flickered Green Red servo continued respond control inputs also exhibited some jitters oscilloscope showed pulses Green port erratic timing pulse widths Red pulses looked normal reset timing Error Switch get solid switch Red no jitters 6 Continuing interference turned off Red transmitter LED indicated Green system selected servo contin ued respond Green system though jittery fashion makes good sense Its better have some control jitters switch dead channel As can easily see addition redun dant radio made dual system almost bullet proof However using two 72 MHz channels leaves us vulnerable same defect mentioned earlier discussed splitting channels groups could used specific lo cationsyou cant sure everyone will cooperate system use right channel right location Working Bob Aberles ham rig Custom Electronics Transmitter T-Module Bobs AM module 534 MHz AM synthesizer module 72 MHz got same results high end six-meter band rarely used might have bit confidence used 53/72 T-Module think everyone should flying everything redundant radios AMA should now create Redundant Radio Phase-In Plan might happen Stay tuned next episode story Interference Fighters George M Myers 70 Froehlich Form Road Hilzksville NY 11801 because power product torque times rpm peak torque generally occurs rpm well below peak power As rpm increases engine produces less force torque because breathing diffi culties less fuel-air mixture gets cylinder stroke higher speeds advisable thus select propeller will permit engine operate just right rpm maximum power As will see moment examine expression power absorp tion speed airplane plays important part problem As matter fact adjustable-pitch pro pellers developed full-size aircraft have used some extent modelsThe formula propeller power power required drive pro peller hp rpm3 X D3 p power coefficient function shape propeller advance ratio Reynolds number Again advance ratio J factors airspeed airplane Note pitch propeller does specifically appear formula included Cp since pitch important factor shape propeller What really important realize propeller power varies cube rpm means twice rpm would require eight times power 10% increase rpm would reflect 33% increase power 20% increase rpm would require 73% increase power Its interesting understand re lationships would nice have some actual numbers stated section thrust its very difficult get useful values thrust coefficient Ct However can get some useful numbers propeller power coefficient Cp * SCALE DOCUMENTATION * SCALE DRAWINGSMODEL PLANS PHOTOS BOOKS EPLA-TECH 1986- INTERNATIONAL AIRPLANE CATALOG OVER 100 PAGES48500 MC KENZIE 1-IWY *300VIDA OREGON 97488 132Model Aviation 11 ATTENTION ERS EPOXY GLASS COWLS FOR NOSEN PICA SIS MORGAN BALSA USA PLATT CONCEPT FLEET HOSTETLER RCM TCRAPT SHEBER PuTS N & N SCALE SUPER CUB FOKKER 57 BOEING P12 P26 F4B2 P4B4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STARDUSTER II IA SCALE J3Bl BABY FLYBABY N 0 TN E B S WHEEL PANTS FOR CITABRIA STARDUSTER II PIUS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE P6E HAWK MULLIGAN H OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete lIst WB supply Modelers fiberglass parts plans Write Call us T & D FIBERGLASS SPECIALTIES 30925 BLOCK GARDEN CITY MI 4B13B PHONE 1313421-6358 BRAZED -TREATED WIRE GEAR5 & CABANES PHONE 313 21-9064 WORLOS ClOSES SCALE enOTO SERVICE 5005 PHBrC PACrSr PLANS EWS PHOTO-PACKSPLANS ENLARGING 5*5E Enlarging coats Catalog 5300SCALE PlANS PHOTO SEll IJICE 3209 MadiSOn GeanSBoB N C 27403 Phone lB1B1292B239 NH CRIIEZII PAWU DIESELS Englands Finest 049 35 RIG STD Send $100 list Eric Clutton 913 Cedar Lane Tullahoma Tenn 37388
Edition: Model Aviation - 1986/10
Page Numbers: 38, 39, 129, 132
G eorg eM Myers QUESTION OF THE DAY improve interference resistance Some people believe have inter ference today 10 years ago Well wrong actually have lot less interference before also have people trying use fewer flying fields pushes us closer together makes modelerto-modeler interference noticeable Ten years ago seven RC channels 72 75 MHz Four assigned Aircraft Only three shared cars boats channels shared other services Given todays explosion interest RC cars boats kinds what sort interference suppose wed have old situation continued significantly has tremen dous increase non-hobby users numbered frequencies 72080 72240 etc must share until 1988 fundamental issue petition FCC new channels concept sharing made ridiculous permitted 300-watt transmitters antennas located 1000 feet above ground restricted hand-held -wave whip antenna FCC listened argument agreed got bonanza AMA critics ignore facts 1 FCC gave us exclusive use new odd-frequency channels 7201 thru 7299 MHz still have exclusivity means non-hobby RC user excluded hobby transmitters new RC channels must radiate approximately same level power similar antennas situation defines less interference 2 AMA gave us Phase-In Plan created controlled environment contin ued use existing equipment protected market improved equipment provided Phase-In Plan prevented kinds interference would have occurred moved immediately old channels spaced 80 kHz new ones spaced 20 kHz 3 place interference-resistance hasnt changed much 31M third-order intermodulation What have now what before channels chose have opportunities 31M consequence uniform channel spacing Supporting bonanza Right begin ning knew some new channels would unusable also knew better receivers required take best advantage what given RC systems manufac turers jumped market created AMA Phase-In Plan packages offering features dreamed few years before might have done new RC channels Some new systems pretty bad Others very good good example lowpriced 1983 Tower Gold 500 transmitter part very early new system Yet passed AMA 1991 tests its plug-in crystals RCl2 RC4O RC5O RC56 Thats better performance anyone expected illustrates point satisfactory trans mitters easier obtain satisfactory receivers Some systems reached market period 1983-1986 worse receivers before vendors usually worked hard replace During same period some very advanced receivers also appeared now have PCM systems Kraft Channel Max synthesized-RF equipment although Kraft itself gone Just week tested prototype receiver shows best performance weve ever seen survives transition production will able buy medium-priced highperformance system transmitter receiver 1987 Reducing interference way careful chan nel selections Time again detractors delight reciting dont need 50 channels because theres no way can use 50 channels simultaneously Baloney could have used beginning worst yesterdays radios wed have break up 50 channels appropriate groups group used flying field keeping flying fields about mile apart observing frequency assignments carefully wouldnt have interference either 31M other kinds possible right now fly Pattern Pylon Scale Helicopters simultaneously same Nats site needed preassign ment RC channels Heres could done no 31M image airport 80kHz channel separation using number channels assigned airport restric tions combinations Pattern airport RCl2 17 21 28 32 37 41 47 51 56 60 Sailplane airport RC11 16 20273136 40 46 50 55 59 Pylon airport RCl5 19 26 30 35 39 4549 54 58 Helicopter airport RC14 182529343844 38 Model Aviation proToType error bwITCfl WlTfl TflO TWO z TOST receivers xnree servos ana DaTterles George started telling us about system last month Switch may stand out background too well larger rectangular object center Fiberglass arrow shafts support receiver antennas column 72240 M Hz slave transmitter simple Sufficient volume remains within mini-box house eight 450 mAh Ni-Cd batteries switch decide needs its own power supply belt-loop bent scrap metal pop-riveted place also receives wire stake ground-based installation desired Two Redundant Radio transmitters Myers Above uses Ace Silver Seven transmit ter slave transmitter worn belt Bob Aberles Below uses Custom Electronics T-Module customized AM Kraft synthesized RF module Slave trans mitter minimally annoying Remember collapse antenna before going through doorways modified buddy-box cable connects master going flying words conjure up images battles balky engines instead carefree days field youre using McDaniel RIC NiStarterTM light plug Ni-StartersTM heavy-duty nicad power will provide up 50 reliable quick starts charge features famous Head LockTM adapter brass reinforcing ring around crimped end really extends its life works sideways inverted information well NiStarter works just go local flying field may have wait NiStartersTM always flying McDaniel RIC Incorporated 12206 Guinevere Road Glenn Dale MD 20769 301/464-2260 Telex 287901 MeD-CR take hassle out hobby 48 53 57 have thank Owen S Black out Carmichael CA scheme produced assignments Owen first person know figured way avoid 31M keep 80-kHz minimum spacing accommo date continued use old radios get benefits have avoid using eight channels RCl3 22 23 24 33 42 43 52 somehow arrange specific RC channels used specific locations likely people will observe restrictions make safer Would competition fliers accept preassigned channels now essentially Would sport fliers select group preassigned frequencies airport observe restrictions voluntar ily likely talking self-discipline Thats AMA keeping pressure manufacturers come up radio systems dont need kind protec tion Most new systems work very well 20 kHz spacing best new receivers showing some improved 31M resistance Now lets look some facts life RC business 1 No matter good RC systems no matter carefully people observe above restrictions will still interference two people try use same frequency same time 2 When system have stops working plane out control Reducing interference means redun Continued page 129 October 1986 39 Consumers Guide Radio Control Products Its Listed THIRD Dont Need EDITION See hobby shop order direct $075 Price $785 plus $180 UPS total ign air mail *13458795 pIus $5 501 u 5 dollars please Send Check MO Credit Card info Consumers Guide 150 Ott St Harrisonburg VA 22S01 4340350 Name Address Charge Card No IMC VISA CHOICEl MasterCard B # ______________________ Expiration flnta SOMETHING NEW & BETTER! THE uii CWfWVTPf4 SPORT/TRAINER SIMPLE TO BUILD EASY TO FLY TRAINER -ORBUILD IT WITH AILERONS AND DO IT ALL OR WITH 05 ELECTRIC MOTOR 48 SPAN SQ IN 43 OZ SELECTED DIE AND MACHINE CUT BALSA AND PLYWOOD COMPLETE ROLLED PLANS STEP-BY-STEP INSTRUCTIONS ALL HARDWARE AND FORMED GEAR FLY WITH 20 FOUR CYCLE ENGINE ASK YOUR DEALER own back gust world dare say turns chases wind Turning wind effect creating gust-like environment head Its kinetic energy has converted something What really downwind turn way As Ken says downwind upwind has killed hundreds people can kill model go round float force bit dont bring up power youd expect strong wind Before war newly-soloed pilots some commercial guys 250 hours flew lightplanes over homesteads girl friends houses strong wind Theyd bank nicely wind gradually keep forcing circle rudder order see house gal simultaneously trying flatten angle bank ailerons cross controls theyd spin terrible mysterious problem until Leighton Collins explained great little magazine Air Facts As beginner wrote couple humble pieces him son editor Flying believe Argue among yourselves Dont bother pros cons share Willards comment Hey fellows lets knock off Just lets say some will lose altitude some wont will go out limb planes drift downwind Half-empty half-full glasses thats air oceanfor models anyway Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 39 simultaneously order get some protection guy turns checking other users channel same scheme simultaneous use two RC channels imple mented way two parallel independent operating systems can also protect us disastrous consequences simple failures like battery exhaustion having battery antenna wire break pretty common occur rences Calvin Orr Custom Electronics recently loaned prototype Error Switch Normally Calvin supports simultaneous use two different bands such 50MHz 72 MHz goal investigate simultaneous use two 72 MHz frequencies Calvin says simultaneous use two 72 MHz channels including Error Detector switch ing can performed today minor modifications presently-available equipment already done Airtronics AM equipment using modified buddy-box connec tion Stage 2 tests Error Switch loaned came equipped 19 Airtronics connectors cheap way todays prices can buy two complete systems simply add Error Switch modified buddy-box cable join complete Redundant Radio system outlay $500 About Error Switch airborne Error Switch $149 item comes two flavors AM FM prototype AM type Error Switch samples both receiver outputs shuts down whichever receiver suffering inter ference FM version has bit sophisti cated order take care FMs capture Continued page 132 NEW FOX 4CycIe Special MIRACLE GLOW PLUG totally new concept glow plug design Instead using idle bar MIRACLE PLUG built pre-cotubustion chanther important thing plug retains heat better other know Try . 4-cycle motor 2-cycle motor also will get smoother throttle reslonse lrolably will able use less exlensive low nitro fuel Tests also show reduced fuel consumption cases WARNING motor Irobably will idle faster reset throttle erwise might able land Hard believe . course check out MIRACLE PLUG Just case 40702 4-Cycle Glow Plug $275 Manufacturing Company 5305 Towson Avenue Fort Smith AR 72901 October 1986 129 I DAVEY EMS CORPORATION E WOOD LANE MALVERN PA 19355 215 644-6772 dant-channel usage should able use two RC channels AERO-PACER $8900 Span 64 1/2 Weight 55 7 lbs Engine 45 61 FS 5 TS ig 25 oz wing loading 4 channel Sport Trainer GIPSY $10900 MOTH Span 543/4 5475 Weight 5-6 lbs 787 sq inches 15 oz wing loading Engine 45 65 FS 0 TS 4 channel Both kits designed primarily Four-Stoke engine fly equally well Two-Stroke engine Add $450 shipping handling Direct SalesMichigan residents add 4B/0 sales tax Check money orderMastercard Visa Radio Techniq ue/MyersPropellers/Abbott Continued page 129Continued page 43 ratio problems Capture ratio refers characteristic FM receivers allows switch allegiance strongest transmitter vicinity FM Redundant Radio system possible rare possible someone operating vicinity channel take control airplane signal stronger receiver signal flying Redundant Radio system gain freedom interference having half system captured foreign transmitter doesnt help FM Error Switch has deal possibility tests Using oscilloscope set up Error Switch transmitter instructed ran few tests 1 The two receivers attached Error Switch attached via Red port Green port An LED light-emitting diode center device indicates system source signals being used control servo both transmitters working Green 72790 MHzRC5O Red old 72240 MHz servo worked normally Error Switch usually showed Green system control 2 When turned off Green transmitter LED indicated Red system 72240 MHz use servo acted normally 3 When turned off Red transmitter LED indicated Green system use servo acted normally 4 When turned off both transmitters LED indicated Red system select ed course servo did nothing 5 With both transmitters operating turned another RC5O Green transmitter LED flickered Green Red servo continued respond control inputs also exhibited some jitters oscilloscope showed pulses Green port erratic timing pulse widths Red pulses looked normal reset timing Error Switch get solid switch Red no jitters 6 Continuing interference turned off Red transmitter LED indicated Green system selected servo contin ued respond Green system though jittery fashion makes good sense Its better have some control jitters switch dead channel As can easily see addition redun dant radio made dual system almost bullet proof However using two 72 MHz channels leaves us vulnerable same defect mentioned earlier discussed splitting channels groups could used specific lo cationsyou cant sure everyone will cooperate system use right channel right location Working Bob Aberles ham rig Custom Electronics Transmitter T-Module Bobs AM module 534 MHz AM synthesizer module 72 MHz got same results high end six-meter band rarely used might have bit confidence used 53/72 T-Module think everyone should flying everything redundant radios AMA should now create Redundant Radio Phase-In Plan might happen Stay tuned next episode story Interference Fighters George M Myers 70 Froehlich Form Road Hilzksville NY 11801 because power product torque times rpm peak torque generally occurs rpm well below peak power As rpm increases engine produces less force torque because breathing diffi culties less fuel-air mixture gets cylinder stroke higher speeds advisable thus select propeller will permit engine operate just right rpm maximum power As will see moment examine expression power absorp tion speed airplane plays important part problem As matter fact adjustable-pitch pro pellers developed full-size aircraft have used some extent modelsThe formula propeller power power required drive pro peller hp rpm3 X D3 p power coefficient function shape propeller advance ratio Reynolds number Again advance ratio J factors airspeed airplane Note pitch propeller does specifically appear formula included Cp since pitch important factor shape propeller What really important realize propeller power varies cube rpm means twice rpm would require eight times power 10% increase rpm would reflect 33% increase power 20% increase rpm would require 73% increase power Its interesting understand re lationships would nice have some actual numbers stated section thrust its very difficult get useful values thrust coefficient Ct However can get some useful numbers propeller power coefficient Cp * SCALE DOCUMENTATION * SCALE DRAWINGSMODEL PLANS PHOTOS BOOKS EPLA-TECH 1986- INTERNATIONAL AIRPLANE CATALOG OVER 100 PAGES48500 MC KENZIE 1-IWY *300VIDA OREGON 97488 132Model Aviation 11 ATTENTION ERS EPOXY GLASS COWLS FOR NOSEN PICA SIS MORGAN BALSA USA PLATT CONCEPT FLEET HOSTETLER RCM TCRAPT SHEBER PuTS N & N SCALE SUPER CUB FOKKER 57 BOEING P12 P26 F4B2 P4B4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STARDUSTER II IA SCALE J3Bl BABY FLYBABY N 0 TN E B S WHEEL PANTS FOR CITABRIA STARDUSTER II PIUS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE P6E HAWK MULLIGAN H OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete lIst WB supply Modelers fiberglass parts plans Write Call us T & D FIBERGLASS SPECIALTIES 30925 BLOCK GARDEN CITY MI 4B13B PHONE 1313421-6358 BRAZED -TREATED WIRE GEAR5 & CABANES PHONE 313 21-9064 WORLOS ClOSES SCALE enOTO SERVICE 5005 PHBrC PACrSr PLANS EWS PHOTO-PACKSPLANS ENLARGING 5*5E Enlarging coats Catalog 5300SCALE PlANS PHOTO SEll IJICE 3209 MadiSOn GeanSBoB N C 27403 Phone lB1B1292B239 NH CRIIEZII PAWU DIESELS Englands Finest 049 35 RIG STD Send $100 list Eric Clutton 913 Cedar Lane Tullahoma Tenn 37388
Edition: Model Aviation - 1986/10
Page Numbers: 38, 39, 129, 132
G eorg eM Myers QUESTION OF THE DAY improve interference resistance Some people believe have inter ference today 10 years ago Well wrong actually have lot less interference before also have people trying use fewer flying fields pushes us closer together makes modelerto-modeler interference noticeable Ten years ago seven RC channels 72 75 MHz Four assigned Aircraft Only three shared cars boats channels shared other services Given todays explosion interest RC cars boats kinds what sort interference suppose wed have old situation continued significantly has tremen dous increase non-hobby users numbered frequencies 72080 72240 etc must share until 1988 fundamental issue petition FCC new channels concept sharing made ridiculous permitted 300-watt transmitters antennas located 1000 feet above ground restricted hand-held -wave whip antenna FCC listened argument agreed got bonanza AMA critics ignore facts 1 FCC gave us exclusive use new odd-frequency channels 7201 thru 7299 MHz still have exclusivity means non-hobby RC user excluded hobby transmitters new RC channels must radiate approximately same level power similar antennas situation defines less interference 2 AMA gave us Phase-In Plan created controlled environment contin ued use existing equipment protected market improved equipment provided Phase-In Plan prevented kinds interference would have occurred moved immediately old channels spaced 80 kHz new ones spaced 20 kHz 3 place interference-resistance hasnt changed much 31M third-order intermodulation What have now what before channels chose have opportunities 31M consequence uniform channel spacing Supporting bonanza Right begin ning knew some new channels would unusable also knew better receivers required take best advantage what given RC systems manufac turers jumped market created AMA Phase-In Plan packages offering features dreamed few years before might have done new RC channels Some new systems pretty bad Others very good good example lowpriced 1983 Tower Gold 500 transmitter part very early new system Yet passed AMA 1991 tests its plug-in crystals RCl2 RC4O RC5O RC56 Thats better performance anyone expected illustrates point satisfactory trans mitters easier obtain satisfactory receivers Some systems reached market period 1983-1986 worse receivers before vendors usually worked hard replace During same period some very advanced receivers also appeared now have PCM systems Kraft Channel Max synthesized-RF equipment although Kraft itself gone Just week tested prototype receiver shows best performance weve ever seen survives transition production will able buy medium-priced highperformance system transmitter receiver 1987 Reducing interference way careful chan nel selections Time again detractors delight reciting dont need 50 channels because theres no way can use 50 channels simultaneously Baloney could have used beginning worst yesterdays radios wed have break up 50 channels appropriate groups group used flying field keeping flying fields about mile apart observing frequency assignments carefully wouldnt have interference either 31M other kinds possible right now fly Pattern Pylon Scale Helicopters simultaneously same Nats site needed preassign ment RC channels Heres could done no 31M image airport 80kHz channel separation using number channels assigned airport restric tions combinations Pattern airport RCl2 17 21 28 32 37 41 47 51 56 60 Sailplane airport RC11 16 20273136 40 46 50 55 59 Pylon airport RCl5 19 26 30 35 39 4549 54 58 Helicopter airport RC14 182529343844 38 Model Aviation proToType error bwITCfl WlTfl TflO TWO z TOST receivers xnree servos ana DaTterles George started telling us about system last month Switch may stand out background too well larger rectangular object center Fiberglass arrow shafts support receiver antennas column 72240 M Hz slave transmitter simple Sufficient volume remains within mini-box house eight 450 mAh Ni-Cd batteries switch decide needs its own power supply belt-loop bent scrap metal pop-riveted place also receives wire stake ground-based installation desired Two Redundant Radio transmitters Myers Above uses Ace Silver Seven transmit ter slave transmitter worn belt Bob Aberles Below uses Custom Electronics T-Module customized AM Kraft synthesized RF module Slave trans mitter minimally annoying Remember collapse antenna before going through doorways modified buddy-box cable connects master going flying words conjure up images battles balky engines instead carefree days field youre using McDaniel RIC NiStarterTM light plug Ni-StartersTM heavy-duty nicad power will provide up 50 reliable quick starts charge features famous Head LockTM adapter brass reinforcing ring around crimped end really extends its life works sideways inverted information well NiStarter works just go local flying field may have wait NiStartersTM always flying McDaniel RIC Incorporated 12206 Guinevere Road Glenn Dale MD 20769 301/464-2260 Telex 287901 MeD-CR take hassle out hobby 48 53 57 have thank Owen S Black out Carmichael CA scheme produced assignments Owen first person know figured way avoid 31M keep 80-kHz minimum spacing accommo date continued use old radios get benefits have avoid using eight channels RCl3 22 23 24 33 42 43 52 somehow arrange specific RC channels used specific locations likely people will observe restrictions make safer Would competition fliers accept preassigned channels now essentially Would sport fliers select group preassigned frequencies airport observe restrictions voluntar ily likely talking self-discipline Thats AMA keeping pressure manufacturers come up radio systems dont need kind protec tion Most new systems work very well 20 kHz spacing best new receivers showing some improved 31M resistance Now lets look some facts life RC business 1 No matter good RC systems no matter carefully people observe above restrictions will still interference two people try use same frequency same time 2 When system have stops working plane out control Reducing interference means redun Continued page 129 October 1986 39 Consumers Guide Radio Control Products Its Listed THIRD Dont Need EDITION See hobby shop order direct $075 Price $785 plus $180 UPS total ign air mail *13458795 pIus $5 501 u 5 dollars please Send Check MO Credit Card info Consumers Guide 150 Ott St Harrisonburg VA 22S01 4340350 Name Address Charge Card No IMC VISA CHOICEl MasterCard B # ______________________ Expiration flnta SOMETHING NEW & BETTER! THE uii CWfWVTPf4 SPORT/TRAINER SIMPLE TO BUILD EASY TO FLY TRAINER -ORBUILD IT WITH AILERONS AND DO IT ALL OR WITH 05 ELECTRIC MOTOR 48 SPAN SQ IN 43 OZ SELECTED DIE AND MACHINE CUT BALSA AND PLYWOOD COMPLETE ROLLED PLANS STEP-BY-STEP INSTRUCTIONS ALL HARDWARE AND FORMED GEAR FLY WITH 20 FOUR CYCLE ENGINE ASK YOUR DEALER own back gust world dare say turns chases wind Turning wind effect creating gust-like environment head Its kinetic energy has converted something What really downwind turn way As Ken says downwind upwind has killed hundreds people can kill model go round float force bit dont bring up power youd expect strong wind Before war newly-soloed pilots some commercial guys 250 hours flew lightplanes over homesteads girl friends houses strong wind Theyd bank nicely wind gradually keep forcing circle rudder order see house gal simultaneously trying flatten angle bank ailerons cross controls theyd spin terrible mysterious problem until Leighton Collins explained great little magazine Air Facts As beginner wrote couple humble pieces him son editor Flying believe Argue among yourselves Dont bother pros cons share Willards comment Hey fellows lets knock off Just lets say some will lose altitude some wont will go out limb planes drift downwind Half-empty half-full glasses thats air oceanfor models anyway Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 39 simultaneously order get some protection guy turns checking other users channel same scheme simultaneous use two RC channels imple mented way two parallel independent operating systems can also protect us disastrous consequences simple failures like battery exhaustion having battery antenna wire break pretty common occur rences Calvin Orr Custom Electronics recently loaned prototype Error Switch Normally Calvin supports simultaneous use two different bands such 50MHz 72 MHz goal investigate simultaneous use two 72 MHz frequencies Calvin says simultaneous use two 72 MHz channels including Error Detector switch ing can performed today minor modifications presently-available equipment already done Airtronics AM equipment using modified buddy-box connec tion Stage 2 tests Error Switch loaned came equipped 19 Airtronics connectors cheap way todays prices can buy two complete systems simply add Error Switch modified buddy-box cable join complete Redundant Radio system outlay $500 About Error Switch airborne Error Switch $149 item comes two flavors AM FM prototype AM type Error Switch samples both receiver outputs shuts down whichever receiver suffering inter ference FM version has bit sophisti cated order take care FMs capture Continued page 132 NEW FOX 4CycIe Special MIRACLE GLOW PLUG totally new concept glow plug design Instead using idle bar MIRACLE PLUG built pre-cotubustion chanther important thing plug retains heat better other know Try . 4-cycle motor 2-cycle motor also will get smoother throttle reslonse lrolably will able use less exlensive low nitro fuel Tests also show reduced fuel consumption cases WARNING motor Irobably will idle faster reset throttle erwise might able land Hard believe . course check out MIRACLE PLUG Just case 40702 4-Cycle Glow Plug $275 Manufacturing Company 5305 Towson Avenue Fort Smith AR 72901 October 1986 129 I DAVEY EMS CORPORATION E WOOD LANE MALVERN PA 19355 215 644-6772 dant-channel usage should able use two RC channels AERO-PACER $8900 Span 64 1/2 Weight 55 7 lbs Engine 45 61 FS 5 TS ig 25 oz wing loading 4 channel Sport Trainer GIPSY $10900 MOTH Span 543/4 5475 Weight 5-6 lbs 787 sq inches 15 oz wing loading Engine 45 65 FS 0 TS 4 channel Both kits designed primarily Four-Stoke engine fly equally well Two-Stroke engine Add $450 shipping handling Direct SalesMichigan residents add 4B/0 sales tax Check money orderMastercard Visa Radio Techniq ue/MyersPropellers/Abbott Continued page 129Continued page 43 ratio problems Capture ratio refers characteristic FM receivers allows switch allegiance strongest transmitter vicinity FM Redundant Radio system possible rare possible someone operating vicinity channel take control airplane signal stronger receiver signal flying Redundant Radio system gain freedom interference having half system captured foreign transmitter doesnt help FM Error Switch has deal possibility tests Using oscilloscope set up Error Switch transmitter instructed ran few tests 1 The two receivers attached Error Switch attached via Red port Green port An LED light-emitting diode center device indicates system source signals being used control servo both transmitters working Green 72790 MHzRC5O Red old 72240 MHz servo worked normally Error Switch usually showed Green system control 2 When turned off Green transmitter LED indicated Red system 72240 MHz use servo acted normally 3 When turned off Red transmitter LED indicated Green system use servo acted normally 4 When turned off both transmitters LED indicated Red system select ed course servo did nothing 5 With both transmitters operating turned another RC5O Green transmitter LED flickered Green Red servo continued respond control inputs also exhibited some jitters oscilloscope showed pulses Green port erratic timing pulse widths Red pulses looked normal reset timing Error Switch get solid switch Red no jitters 6 Continuing interference turned off Red transmitter LED indicated Green system selected servo contin ued respond Green system though jittery fashion makes good sense Its better have some control jitters switch dead channel As can easily see addition redun dant radio made dual system almost bullet proof However using two 72 MHz channels leaves us vulnerable same defect mentioned earlier discussed splitting channels groups could used specific lo cationsyou cant sure everyone will cooperate system use right channel right location Working Bob Aberles ham rig Custom Electronics Transmitter T-Module Bobs AM module 534 MHz AM synthesizer module 72 MHz got same results high end six-meter band rarely used might have bit confidence used 53/72 T-Module think everyone should flying everything redundant radios AMA should now create Redundant Radio Phase-In Plan might happen Stay tuned next episode story Interference Fighters George M Myers 70 Froehlich Form Road Hilzksville NY 11801 because power product torque times rpm peak torque generally occurs rpm well below peak power As rpm increases engine produces less force torque because breathing diffi culties less fuel-air mixture gets cylinder stroke higher speeds advisable thus select propeller will permit engine operate just right rpm maximum power As will see moment examine expression power absorp tion speed airplane plays important part problem As matter fact adjustable-pitch pro pellers developed full-size aircraft have used some extent modelsThe formula propeller power power required drive pro peller hp rpm3 X D3 p power coefficient function shape propeller advance ratio Reynolds number Again advance ratio J factors airspeed airplane Note pitch propeller does specifically appear formula included Cp since pitch important factor shape propeller What really important realize propeller power varies cube rpm means twice rpm would require eight times power 10% increase rpm would reflect 33% increase power 20% increase rpm would require 73% increase power Its interesting understand re lationships would nice have some actual numbers stated section thrust its very difficult get useful values thrust coefficient Ct However can get some useful numbers propeller power coefficient Cp * SCALE DOCUMENTATION * SCALE DRAWINGSMODEL PLANS PHOTOS BOOKS EPLA-TECH 1986- INTERNATIONAL AIRPLANE CATALOG OVER 100 PAGES48500 MC KENZIE 1-IWY *300VIDA OREGON 97488 132Model Aviation 11 ATTENTION ERS EPOXY GLASS COWLS FOR NOSEN PICA SIS MORGAN BALSA USA PLATT CONCEPT FLEET HOSTETLER RCM TCRAPT SHEBER PuTS N & N SCALE SUPER CUB FOKKER 57 BOEING P12 P26 F4B2 P4B4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STARDUSTER II IA SCALE J3Bl BABY FLYBABY N 0 TN E B S WHEEL PANTS FOR CITABRIA STARDUSTER II PIUS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE P6E HAWK MULLIGAN H OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete lIst WB supply Modelers fiberglass parts plans Write Call us T & D FIBERGLASS SPECIALTIES 30925 BLOCK GARDEN CITY MI 4B13B PHONE 1313421-6358 BRAZED -TREATED WIRE GEAR5 & CABANES PHONE 313 21-9064 WORLOS ClOSES SCALE enOTO SERVICE 5005 PHBrC PACrSr PLANS EWS PHOTO-PACKSPLANS ENLARGING 5*5E Enlarging coats Catalog 5300SCALE PlANS PHOTO SEll IJICE 3209 MadiSOn GeanSBoB N C 27403 Phone lB1B1292B239 NH CRIIEZII PAWU DIESELS Englands Finest 049 35 RIG STD Send $100 list Eric Clutton 913 Cedar Lane Tullahoma Tenn 37388
Edition: Model Aviation - 1986/10
Page Numbers: 38, 39, 129, 132
G eorg eM Myers QUESTION OF THE DAY improve interference resistance Some people believe have inter ference today 10 years ago Well wrong actually have lot less interference before also have people trying use fewer flying fields pushes us closer together makes modelerto-modeler interference noticeable Ten years ago seven RC channels 72 75 MHz Four assigned Aircraft Only three shared cars boats channels shared other services Given todays explosion interest RC cars boats kinds what sort interference suppose wed have old situation continued significantly has tremen dous increase non-hobby users numbered frequencies 72080 72240 etc must share until 1988 fundamental issue petition FCC new channels concept sharing made ridiculous permitted 300-watt transmitters antennas located 1000 feet above ground restricted hand-held -wave whip antenna FCC listened argument agreed got bonanza AMA critics ignore facts 1 FCC gave us exclusive use new odd-frequency channels 7201 thru 7299 MHz still have exclusivity means non-hobby RC user excluded hobby transmitters new RC channels must radiate approximately same level power similar antennas situation defines less interference 2 AMA gave us Phase-In Plan created controlled environment contin ued use existing equipment protected market improved equipment provided Phase-In Plan prevented kinds interference would have occurred moved immediately old channels spaced 80 kHz new ones spaced 20 kHz 3 place interference-resistance hasnt changed much 31M third-order intermodulation What have now what before channels chose have opportunities 31M consequence uniform channel spacing Supporting bonanza Right begin ning knew some new channels would unusable also knew better receivers required take best advantage what given RC systems manufac turers jumped market created AMA Phase-In Plan packages offering features dreamed few years before might have done new RC channels Some new systems pretty bad Others very good good example lowpriced 1983 Tower Gold 500 transmitter part very early new system Yet passed AMA 1991 tests its plug-in crystals RCl2 RC4O RC5O RC56 Thats better performance anyone expected illustrates point satisfactory trans mitters easier obtain satisfactory receivers Some systems reached market period 1983-1986 worse receivers before vendors usually worked hard replace During same period some very advanced receivers also appeared now have PCM systems Kraft Channel Max synthesized-RF equipment although Kraft itself gone Just week tested prototype receiver shows best performance weve ever seen survives transition production will able buy medium-priced highperformance system transmitter receiver 1987 Reducing interference way careful chan nel selections Time again detractors delight reciting dont need 50 channels because theres no way can use 50 channels simultaneously Baloney could have used beginning worst yesterdays radios wed have break up 50 channels appropriate groups group used flying field keeping flying fields about mile apart observing frequency assignments carefully wouldnt have interference either 31M other kinds possible right now fly Pattern Pylon Scale Helicopters simultaneously same Nats site needed preassign ment RC channels Heres could done no 31M image airport 80kHz channel separation using number channels assigned airport restric tions combinations Pattern airport RCl2 17 21 28 32 37 41 47 51 56 60 Sailplane airport RC11 16 20273136 40 46 50 55 59 Pylon airport RCl5 19 26 30 35 39 4549 54 58 Helicopter airport RC14 182529343844 38 Model Aviation proToType error bwITCfl WlTfl TflO TWO z TOST receivers xnree servos ana DaTterles George started telling us about system last month Switch may stand out background too well larger rectangular object center Fiberglass arrow shafts support receiver antennas column 72240 M Hz slave transmitter simple Sufficient volume remains within mini-box house eight 450 mAh Ni-Cd batteries switch decide needs its own power supply belt-loop bent scrap metal pop-riveted place also receives wire stake ground-based installation desired Two Redundant Radio transmitters Myers Above uses Ace Silver Seven transmit ter slave transmitter worn belt Bob Aberles Below uses Custom Electronics T-Module customized AM Kraft synthesized RF module Slave trans mitter minimally annoying Remember collapse antenna before going through doorways modified buddy-box cable connects master going flying words conjure up images battles balky engines instead carefree days field youre using McDaniel RIC NiStarterTM light plug Ni-StartersTM heavy-duty nicad power will provide up 50 reliable quick starts charge features famous Head LockTM adapter brass reinforcing ring around crimped end really extends its life works sideways inverted information well NiStarter works just go local flying field may have wait NiStartersTM always flying McDaniel RIC Incorporated 12206 Guinevere Road Glenn Dale MD 20769 301/464-2260 Telex 287901 MeD-CR take hassle out hobby 48 53 57 have thank Owen S Black out Carmichael CA scheme produced assignments Owen first person know figured way avoid 31M keep 80-kHz minimum spacing accommo date continued use old radios get benefits have avoid using eight channels RCl3 22 23 24 33 42 43 52 somehow arrange specific RC channels used specific locations likely people will observe restrictions make safer Would competition fliers accept preassigned channels now essentially Would sport fliers select group preassigned frequencies airport observe restrictions voluntar ily likely talking self-discipline Thats AMA keeping pressure manufacturers come up radio systems dont need kind protec tion Most new systems work very well 20 kHz spacing best new receivers showing some improved 31M resistance Now lets look some facts life RC business 1 No matter good RC systems no matter carefully people observe above restrictions will still interference two people try use same frequency same time 2 When system have stops working plane out control Reducing interference means redun Continued page 129 October 1986 39 Consumers Guide Radio Control Products Its Listed THIRD Dont Need EDITION See hobby shop order direct $075 Price $785 plus $180 UPS total ign air mail *13458795 pIus $5 501 u 5 dollars please Send Check MO Credit Card info Consumers Guide 150 Ott St Harrisonburg VA 22S01 4340350 Name Address Charge Card No IMC VISA CHOICEl MasterCard B # ______________________ Expiration flnta SOMETHING NEW & BETTER! THE uii CWfWVTPf4 SPORT/TRAINER SIMPLE TO BUILD EASY TO FLY TRAINER -ORBUILD IT WITH AILERONS AND DO IT ALL OR WITH 05 ELECTRIC MOTOR 48 SPAN SQ IN 43 OZ SELECTED DIE AND MACHINE CUT BALSA AND PLYWOOD COMPLETE ROLLED PLANS STEP-BY-STEP INSTRUCTIONS ALL HARDWARE AND FORMED GEAR FLY WITH 20 FOUR CYCLE ENGINE ASK YOUR DEALER own back gust world dare say turns chases wind Turning wind effect creating gust-like environment head Its kinetic energy has converted something What really downwind turn way As Ken says downwind upwind has killed hundreds people can kill model go round float force bit dont bring up power youd expect strong wind Before war newly-soloed pilots some commercial guys 250 hours flew lightplanes over homesteads girl friends houses strong wind Theyd bank nicely wind gradually keep forcing circle rudder order see house gal simultaneously trying flatten angle bank ailerons cross controls theyd spin terrible mysterious problem until Leighton Collins explained great little magazine Air Facts As beginner wrote couple humble pieces him son editor Flying believe Argue among yourselves Dont bother pros cons share Willards comment Hey fellows lets knock off Just lets say some will lose altitude some wont will go out limb planes drift downwind Half-empty half-full glasses thats air oceanfor models anyway Bill Winter 4432 Altura Ct Fairfax VA 22030 Radio Technique/Myers Continued page 39 simultaneously order get some protection guy turns checking other users channel same scheme simultaneous use two RC channels imple mented way two parallel independent operating systems can also protect us disastrous consequences simple failures like battery exhaustion having battery antenna wire break pretty common occur rences Calvin Orr Custom Electronics recently loaned prototype Error Switch Normally Calvin supports simultaneous use two different bands such 50MHz 72 MHz goal investigate simultaneous use two 72 MHz frequencies Calvin says simultaneous use two 72 MHz channels including Error Detector switch ing can performed today minor modifications presently-available equipment already done Airtronics AM equipment using modified buddy-box connec tion Stage 2 tests Error Switch loaned came equipped 19 Airtronics connectors cheap way todays prices can buy two complete systems simply add Error Switch modified buddy-box cable join complete Redundant Radio system outlay $500 About Error Switch airborne Error Switch $149 item comes two flavors AM FM prototype AM type Error Switch samples both receiver outputs shuts down whichever receiver suffering inter ference FM version has bit sophisti cated order take care FMs capture Continued page 132 NEW FOX 4CycIe Special MIRACLE GLOW PLUG totally new concept glow plug design Instead using idle bar MIRACLE PLUG built pre-cotubustion chanther important thing plug retains heat better other know Try . 4-cycle motor 2-cycle motor also will get smoother throttle reslonse lrolably will able use less exlensive low nitro fuel Tests also show reduced fuel consumption cases WARNING motor Irobably will idle faster reset throttle erwise might able land Hard believe . course check out MIRACLE PLUG Just case 40702 4-Cycle Glow Plug $275 Manufacturing Company 5305 Towson Avenue Fort Smith AR 72901 October 1986 129 I DAVEY EMS CORPORATION E WOOD LANE MALVERN PA 19355 215 644-6772 dant-channel usage should able use two RC channels AERO-PACER $8900 Span 64 1/2 Weight 55 7 lbs Engine 45 61 FS 5 TS ig 25 oz wing loading 4 channel Sport Trainer GIPSY $10900 MOTH Span 543/4 5475 Weight 5-6 lbs 787 sq inches 15 oz wing loading Engine 45 65 FS 0 TS 4 channel Both kits designed primarily Four-Stoke engine fly equally well Two-Stroke engine Add $450 shipping handling Direct SalesMichigan residents add 4B/0 sales tax Check money orderMastercard Visa Radio Techniq ue/MyersPropellers/Abbott Continued page 129Continued page 43 ratio problems Capture ratio refers characteristic FM receivers allows switch allegiance strongest transmitter vicinity FM Redundant Radio system possible rare possible someone operating vicinity channel take control airplane signal stronger receiver signal flying Redundant Radio system gain freedom interference having half system captured foreign transmitter doesnt help FM Error Switch has deal possibility tests Using oscilloscope set up Error Switch transmitter instructed ran few tests 1 The two receivers attached Error Switch attached via Red port Green port An LED light-emitting diode center device indicates system source signals being used control servo both transmitters working Green 72790 MHzRC5O Red old 72240 MHz servo worked normally Error Switch usually showed Green system control 2 When turned off Green transmitter LED indicated Red system 72240 MHz use servo acted normally 3 When turned off Red transmitter LED indicated Green system use servo acted normally 4 When turned off both transmitters LED indicated Red system select ed course servo did nothing 5 With both transmitters operating turned another RC5O Green transmitter LED flickered Green Red servo continued respond control inputs also exhibited some jitters oscilloscope showed pulses Green port erratic timing pulse widths Red pulses looked normal reset timing Error Switch get solid switch Red no jitters 6 Continuing interference turned off Red transmitter LED indicated Green system selected servo contin ued respond Green system though jittery fashion makes good sense Its better have some control jitters switch dead channel As can easily see addition redun dant radio made dual system almost bullet proof However using two 72 MHz channels leaves us vulnerable same defect mentioned earlier discussed splitting channels groups could used specific lo cationsyou cant sure everyone will cooperate system use right channel right location Working Bob Aberles ham rig Custom Electronics Transmitter T-Module Bobs AM module 534 MHz AM synthesizer module 72 MHz got same results high end six-meter band rarely used might have bit confidence used 53/72 T-Module think everyone should flying everything redundant radios AMA should now create Redundant Radio Phase-In Plan might happen Stay tuned next episode story Interference Fighters George M Myers 70 Froehlich Form Road Hilzksville NY 11801 because power product torque times rpm peak torque generally occurs rpm well below peak power As rpm increases engine produces less force torque because breathing diffi culties less fuel-air mixture gets cylinder stroke higher speeds advisable thus select propeller will permit engine operate just right rpm maximum power As will see moment examine expression power absorp tion speed airplane plays important part problem As matter fact adjustable-pitch pro pellers developed full-size aircraft have used some extent modelsThe formula propeller power power required drive pro peller hp rpm3 X D3 p power coefficient function shape propeller advance ratio Reynolds number Again advance ratio J factors airspeed airplane Note pitch propeller does specifically appear formula included Cp since pitch important factor shape propeller What really important realize propeller power varies cube rpm means twice rpm would require eight times power 10% increase rpm would reflect 33% increase power 20% increase rpm would require 73% increase power Its interesting understand re lationships would nice have some actual numbers stated section thrust its very difficult get useful values thrust coefficient Ct However can get some useful numbers propeller power coefficient Cp * SCALE DOCUMENTATION * SCALE DRAWINGSMODEL PLANS PHOTOS BOOKS EPLA-TECH 1986- INTERNATIONAL AIRPLANE CATALOG OVER 100 PAGES48500 MC KENZIE 1-IWY *300VIDA OREGON 97488 132Model Aviation 11 ATTENTION ERS EPOXY GLASS COWLS FOR NOSEN PICA SIS MORGAN BALSA USA PLATT CONCEPT FLEET HOSTETLER RCM TCRAPT SHEBER PuTS N & N SCALE SUPER CUB FOKKER 57 BOEING P12 P26 F4B2 P4B4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STARDUSTER II IA SCALE J3Bl BABY FLYBABY N 0 TN E B S WHEEL PANTS FOR CITABRIA STARDUSTER II PIUS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE P6E HAWK MULLIGAN H OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete lIst WB supply Modelers fiberglass parts plans Write Call us T & D FIBERGLASS SPECIALTIES 30925 BLOCK GARDEN CITY MI 4B13B PHONE 1313421-6358 BRAZED -TREATED WIRE GEAR5 & CABANES PHONE 313 21-9064 WORLOS ClOSES SCALE enOTO SERVICE 5005 PHBrC PACrSr PLANS EWS PHOTO-PACKSPLANS ENLARGING 5*5E Enlarging coats Catalog 5300SCALE PlANS PHOTO SEll IJICE 3209 MadiSOn GeanSBoB N C 27403 Phone lB1B1292B239 NH CRIIEZII PAWU DIESELS Englands Finest 049 35 RIG STD Send $100 list Eric Clutton 913 Cedar Lane Tullahoma Tenn 37388