Technique~ Myers THERE ARE SOME rewards writing business opportunity learn people really take work seriously Upon returning summers vacation found following letter Mr D H Reyburn Merced Cal have excerpted Shortly after reading Sept 76 column really crashed RC plane receiver found completely inoperative Using article gen eral guide checked out obvious pos sibilities including shake listen broken crystal bit no luck Now reason letter transmitter inoperative re ceiver turned decided turn other receiver same frequency check transmitter ground range Aha both re ceivers worked perfectly Turn off #2 re ceiver #1 also dies removed suspect crystal #1 repeated test Again both worked due time replaced defective crystal #1 both receivers worked normally valid test broken crystals worth mentioning column Inci dentally #1 receiver also worked same way another system different frequency test valid Mr Reyburn thank telling us about local oscillator superhetrodyne receiver will radiate signal receiver tenna fact root recent decision FCC add 17 chan nels CB spectrum rather larger numbers originally proposed CB sets oscil lator radiations strong interfere another well TV channel 2 host other radio systems 17-channel allocation mini mizes added interference expand ing CB band will cause Back Mr Reyburns test signal radiated #2 receiver picked up #1 along signal transmitter difference between normal 455KHz passed right through intermediate frequency amplifiers should normal control signal de coded passed servos tech nician suspected broken crystal would have done same thing Mr Reyburn except would have used tool called grid-dip oscillator instead another receiver signal source probability using GDO would have work much harder Mr Reyburn did because would have adjust GDO very carefully order get results Thanks again good idea Incidentally Mr Reyburn used best tools havepersistence test doesnt solve problem try another Dl D2 PLi PL 2 PL3 CONNECT GLOW PLUG WIRES HERE 00 Jo SW 1 PUSH TO TEST GLOW PLUG CHARGING JACK CII SW 2 MASTER12v AUTO SWITCHIIBATTERY Dl D2 SILICON DIODES RATED 50v/1OA OR MORE PLi 15 TO 22v FLASHLIGHT BULB PL2PL3 12vAUTOMOBILE BULBS SWi SPDT ON/MOMENTARY RATED 1 25vI5A 5W2 SPDT ON/ON RATED 125v/lOA FIG 1 DON TURN EYS AUTOMATIC GLOW PLUG HEATER Glow-Plug Power Source Mr Donald Turney AMA 51780 Pompton Plains NJ has submitted idea beautifully simple source glo plug power As shown Fig 1 Mr Tur ney connects two high-power silicon diodes series 12-volt starter motor uses characteristic 6/10 volt ward drop conducting PN silicon junction act regulated voltage source Connected shown glow plug receives current starter mo tor turning pilot light #1 lights advise fact Pilot light #2 lights push switch #1 test position indicate continuity through glow plug Pilot light #3 glows time system turned As presented Mr Turneys circuit also included regu lated 9-volt power supply transmit ter have deleted interest limiting number letters will have answer leave Some transmit ters use charging jacks discon nected transmitter operating would require transmitter modifi cation use circuit Other systems op erate 12 volts enough poten tial damaging mistake Id rather propose gb-plug idea great use stud-mounted diodes Silicon Germanium mount separate pieces aluminum angle heat-sinks Putting same piece would create short circuit defeat purpose 10 Model Aviation George Hill Lowe-designed Phoenix 7 Some changes compared 6 increased rudder part vertical area thicker stab high CONNECTer mounted revised airfoil better streamlining ELECTRICand epoxy glass fuselagenot polyester STARTER WIRES HERE 0 Downwind Turns . Say George whats scoop downwind turns Are danger ous other turns theme has appeared several letters recently prompted no doubt circulationbuilding controversy reported nonmodel aviation magazine Pick calm day fly airplane circle about 100 feet above head will easy Throttle elevator aile ron controls can kept essentially con stant positions Now repeat exercise windy day will find must continuously adjust three con trols particularly try maintain constant ground-speed circumfer ence circle reason wind keeps trying blow airplane downwind Note bank angle must vary continuously around circle use maximum bank angle downwind minimum bank angle upwind Fig 2 Fig 3 shows g-load wings increases bank angle increased load raises stalling speed airplane given angle attack wing Moving now consideration rec tangular landing pattern described paragraph 1315 page 80 1976-77 Official Model Aircraft Regulations lets look what trying accom plish 1 slowing down land maintaining constant altitude 2 attempting fly rectangular track over ground Since model air planes present have no instrumentation tells us airspeed angle attack mostly fly aircraft atti tude see Since wind trying blow us beyond third turn point natural tendency slow right down stalling airspeed downwind leg nose high bank hard over third turn increased stall ing speed results crosses right over flying speed see classic approach stall followed spin Thats downwind turn dangerous Keep airspeed up start turn earlier wind blows harder problem manageable have ideas share pro bl ems solve address George M Myers 70 Froehlich Farm Rd Hicksville N Y. 11801 MAXIMUM BANK ANGLE MUM UP ELEVATOR MINIMUM THROTTLE DECREASING BANK 7 AND PITCH ANGLE EASING POWER FIG2 N FLYING CIRCLE AROUND POINT ON THE GROUND WHEN WIND IS BLOWING REQUIRES CONTINUOUS CONTROL ADJUSTMENTS INCREASING BANK AND PITCH ANGLE DECREASING POWER MINIMUM BANK ANGLE MINIMUM UP ELEVATOR MAXIMUM THROTTLE 10 9 8 7 6 5 4 3 2 0 B ANGLE IN DEGREES C, 0 C z z 0 0 0 -J 0 10 20 30 40 50 60 70 80 90 FIG 3 G LOAD ON THE WING INCREASES WITH BANK ANGLE CAUSING INCREASE IN STALLING SPEED AT ANY GIVEN ANGLE OF ATTACK December1976 11 Prototype frequency monitor World Engines scans frequencies within its range just selected frequencies emits audible squeal transmissionloud squeal two transmitters Meaa production confirmed though rumors have will be
Edition: Model Aviation - 1976/12
Page Numbers: 10, 11
Technique~ Myers THERE ARE SOME rewards writing business opportunity learn people really take work seriously Upon returning summers vacation found following letter Mr D H Reyburn Merced Cal have excerpted Shortly after reading Sept 76 column really crashed RC plane receiver found completely inoperative Using article gen eral guide checked out obvious pos sibilities including shake listen broken crystal bit no luck Now reason letter transmitter inoperative re ceiver turned decided turn other receiver same frequency check transmitter ground range Aha both re ceivers worked perfectly Turn off #2 re ceiver #1 also dies removed suspect crystal #1 repeated test Again both worked due time replaced defective crystal #1 both receivers worked normally valid test broken crystals worth mentioning column Inci dentally #1 receiver also worked same way another system different frequency test valid Mr Reyburn thank telling us about local oscillator superhetrodyne receiver will radiate signal receiver tenna fact root recent decision FCC add 17 chan nels CB spectrum rather larger numbers originally proposed CB sets oscil lator radiations strong interfere another well TV channel 2 host other radio systems 17-channel allocation mini mizes added interference expand ing CB band will cause Back Mr Reyburns test signal radiated #2 receiver picked up #1 along signal transmitter difference between normal 455KHz passed right through intermediate frequency amplifiers should normal control signal de coded passed servos tech nician suspected broken crystal would have done same thing Mr Reyburn except would have used tool called grid-dip oscillator instead another receiver signal source probability using GDO would have work much harder Mr Reyburn did because would have adjust GDO very carefully order get results Thanks again good idea Incidentally Mr Reyburn used best tools havepersistence test doesnt solve problem try another Dl D2 PLi PL 2 PL3 CONNECT GLOW PLUG WIRES HERE 00 Jo SW 1 PUSH TO TEST GLOW PLUG CHARGING JACK CII SW 2 MASTER12v AUTO SWITCHIIBATTERY Dl D2 SILICON DIODES RATED 50v/1OA OR MORE PLi 15 TO 22v FLASHLIGHT BULB PL2PL3 12vAUTOMOBILE BULBS SWi SPDT ON/MOMENTARY RATED 1 25vI5A 5W2 SPDT ON/ON RATED 125v/lOA FIG 1 DON TURN EYS AUTOMATIC GLOW PLUG HEATER Glow-Plug Power Source Mr Donald Turney AMA 51780 Pompton Plains NJ has submitted idea beautifully simple source glo plug power As shown Fig 1 Mr Tur ney connects two high-power silicon diodes series 12-volt starter motor uses characteristic 6/10 volt ward drop conducting PN silicon junction act regulated voltage source Connected shown glow plug receives current starter mo tor turning pilot light #1 lights advise fact Pilot light #2 lights push switch #1 test position indicate continuity through glow plug Pilot light #3 glows time system turned As presented Mr Turneys circuit also included regu lated 9-volt power supply transmit ter have deleted interest limiting number letters will have answer leave Some transmit ters use charging jacks discon nected transmitter operating would require transmitter modifi cation use circuit Other systems op erate 12 volts enough poten tial damaging mistake Id rather propose gb-plug idea great use stud-mounted diodes Silicon Germanium mount separate pieces aluminum angle heat-sinks Putting same piece would create short circuit defeat purpose 10 Model Aviation George Hill Lowe-designed Phoenix 7 Some changes compared 6 increased rudder part vertical area thicker stab high CONNECTer mounted revised airfoil better streamlining ELECTRICand epoxy glass fuselagenot polyester STARTER WIRES HERE 0 Downwind Turns . Say George whats scoop downwind turns Are danger ous other turns theme has appeared several letters recently prompted no doubt circulationbuilding controversy reported nonmodel aviation magazine Pick calm day fly airplane circle about 100 feet above head will easy Throttle elevator aile ron controls can kept essentially con stant positions Now repeat exercise windy day will find must continuously adjust three con trols particularly try maintain constant ground-speed circumfer ence circle reason wind keeps trying blow airplane downwind Note bank angle must vary continuously around circle use maximum bank angle downwind minimum bank angle upwind Fig 2 Fig 3 shows g-load wings increases bank angle increased load raises stalling speed airplane given angle attack wing Moving now consideration rec tangular landing pattern described paragraph 1315 page 80 1976-77 Official Model Aircraft Regulations lets look what trying accom plish 1 slowing down land maintaining constant altitude 2 attempting fly rectangular track over ground Since model air planes present have no instrumentation tells us airspeed angle attack mostly fly aircraft atti tude see Since wind trying blow us beyond third turn point natural tendency slow right down stalling airspeed downwind leg nose high bank hard over third turn increased stall ing speed results crosses right over flying speed see classic approach stall followed spin Thats downwind turn dangerous Keep airspeed up start turn earlier wind blows harder problem manageable have ideas share pro bl ems solve address George M Myers 70 Froehlich Farm Rd Hicksville N Y. 11801 MAXIMUM BANK ANGLE MUM UP ELEVATOR MINIMUM THROTTLE DECREASING BANK 7 AND PITCH ANGLE EASING POWER FIG2 N FLYING CIRCLE AROUND POINT ON THE GROUND WHEN WIND IS BLOWING REQUIRES CONTINUOUS CONTROL ADJUSTMENTS INCREASING BANK AND PITCH ANGLE DECREASING POWER MINIMUM BANK ANGLE MINIMUM UP ELEVATOR MAXIMUM THROTTLE 10 9 8 7 6 5 4 3 2 0 B ANGLE IN DEGREES C, 0 C z z 0 0 0 -J 0 10 20 30 40 50 60 70 80 90 FIG 3 G LOAD ON THE WING INCREASES WITH BANK ANGLE CAUSING INCREASE IN STALLING SPEED AT ANY GIVEN ANGLE OF ATTACK December1976 11 Prototype frequency monitor World Engines scans frequencies within its range just selected frequencies emits audible squeal transmissionloud squeal two transmitters Meaa production confirmed though rumors have will be