Batteries Diodes WHILE HELPING friend pick up pieces moved ask him day 3-wire servos low-volt age receivers would operate radio system diode protection battery pack answer simple direct Because dont know what size use install Before beginning step-by-step instructibn little background information may order nicad battery single-point failure item system battery fails system stops operating Batter ies fail two modes Open no current flows through Short no voltage generated current does flow through battery driven other operating batteries Short circuits com mon frequently caused letting battery lie unattended over winter season spends con siderable time 0 volts state dis charge short-circuited cell battery pack will cause system show decreased range shorted cell airborne pack servos will run slower An open cell acts just like switch turns system oW diode device conducts cur rent freely direction ideally opposite direction makes ideal purposes because can connect across battery will conduct same direction battery fear discharging cell accidently See Fig 1 Now shunt cell battery pack Radio Technique George M Myers 9 FIG 1 DIODESHUNTED BATTERY FIG 2 DIODE TEST SETUP BATTERY PACK 100HMSV 10 WATT4- RESISTORVOLTMETER INSTALL DIODES HERE FOR TEST U diode cell can develop open circuit turning system off price service voltage drop caused diode conducting fully-charged airborne pack output voltage will drop about 56 42 VDC cell develops short will drop zero cell develops open circuit course Connecting diode across open cell will restore circuit output about 34 volts missing voltage absorbed diode worst case pack 44 volts will drop 25 volts Now modern receivers will operate voltages around 30 reli ably 3-wire servos will still func tion slowly weakly voltage will allow least chance making good landing after things go sour Pro-Line Electronics 10632 North 21st Ave Suite 11 Phoenix AZ 85029 first use diode-protected battery packs commercially far know still offer Readers desire diode protection unsure ability install own strongly advised buy such packs want blamed problems arising incorrect installations Connecting diode backwards will discharge bat tery should notice problem right away because diode will get hot still buy some sili con diodes rated at least 1 amp 50 volts such 1N4001 Next test diode setup Fig 2 Test diode both ways voltmeter should read about 52 volts no diode connected should read same diode connected card diode diode marked band around body diode diode connected icated voltage should less 08 volts higher voltage seen set diode aside some other use Fig 3 shows World Engines Expert pack diode string assembled fitted groove formed walls cylindrical cells Note flexible wires provided make connections cells done allow some free motion purpose installing cells back pack rigid setup might break Fig 4 shows diodes stalled pack ready reassem bled Note shrink tubing has used insulate bare metal parts Failure can lead short circuits worse condition trying avoid Note also soldering done tabs cells 60/40 rosin-core solder used Acid solder fluxes will ruin pack completely unnecessary 8 Model Aviation Fg 3 World Engines Export battery pack diode string assembled fitted groove formed walls cylindrical cells Diode protection will prevent open cell shutting off system least can get ship safely down because tabs accept solder very easily Avoid large solder buildup wont get cells back case Use 27- 40-watt soldering iron 1/t chisel point soldering Fig 5 schematic diagram diode-protected pack Transmitter packs can should protected same way However some disassembly transmitter will required have slightest doubt ability correctly dont try Open circuits nicad batteries primarily result vibration transmitter isnt subjected much What happens internal connection active material battery separates pretty easy understand consider material spongy mass pressed window-screen type support Its solid metal therefore connec tion can broken down severe vibra tion such can transmitted engine fail protect pack foam rubber everyone tells you should subject Id like mention flying buddy ran some rather severe vibration tests manufacturers cell could find test results demonstrated thing conclusively foam rubber essen tial Theres no vibration-proof battery available time Citizens Radio Service provides totally inadequate 23 channels use 200000000 citizens put way emphasize problem Sure know band used mis-used types citizens both law-abiding outlaws Nonetheless service inadequate also beyond ability FCC control Personally stopped using 27-MHz band 1970 could no longer tolerate inter ferences illegal kilowatt amplifiers 5watt Walkie-Talkies using RC crystals legal powerful transmitters Navy Special Devices Center Sands Point NY barely 20 miles away Other folks continue use band satisfactorily above will become academic FCC Docket 20120 released March 29 1976 adopted unchanged docu ment intended elicit comments industry public Replies due May 26 1976 Simply stated FCC proposes take away five RC fre quencies 27-MHz band Using frequencles others present Class D service will yield about 100 CR channels through magic single-sideband operation changes will bring about promise obso lete existing CR transreceiver put several thousand land mobile stations out service require modification thousands RC systems can see move taken light ly however interim move purposes providing immediate relief users Citizens Radio Service FCC also considering moving Citizens Radio Service 220 MHz 900 MHz order elimi nate skip-chasing becomes popular illegal pastime among CR opera tors during periods high sunspot activ ity RC systems could benefit such move because would operate satisfactorily much shorter airborne antennas simpler receivers continued page 8 r MV5023 RED 220 OHMS 3 V 01 PF 4 1N4001 4L2vr4 NICAD BATTERIES 4 FIG 5 SCHEMATIC DIAGRAM OF DIODE-PROTECTED PACK S 1 7 6 211 22 MF 15VDC S TO 12VDC 0 33K 1N751 K p10K 0 VOLTS July1976 9 Fig 4 diodes shown installed Wt Expert pack ready reassembly Flex ible wires provided connections cellsheat-shrink tubing used insulate bare metal parts NE 555 FIG 6 ADJUSTABLE CRITICAL VOLTAGE INDICATOR simple inexpensive sturdy internal switnh mnunt install sin jiffy dnuble sided nape en fuse sidO/fnrmar nr bantam junvtlnn Nn drilling nr homing ewkward erats Takes up wunh less mum nthar similar mnunneperfect fnr emaIl planes Fnr Nable Switchnraf nr ndter switch 1 Sn I/B between meunting 4OL20gAna Nnble Infernal SwItch Mnunt $89 Please send complete catalog Enclosed 8100 refunded first order Add 850 1st class null return add $100 handling other rs Like Enilders Triangles Triangles II era enanhar handy mnrkshep aid whiub ynull find indIspensable triangles hane has nan thumb tank thant Se building surtaus end hate Inettet jig fee fun age tonntruntinn Also bane immediately salfeliga leg terminal ynu eacured ofe perpandinular rudder glu Ito stab--the tamer tho triangle removed glue jaint filer Isnt disturbed made aluminum durability plot makat nhem anne straight edge fur cutting Enary wnrkshop needs pair 31 LBAve Triangles II nec pair 5550 SAME ADDRESS STATE ACE WRAP N TIES Nylga strop tighten dawn wont gusts up Handy fur uses Organlalna transmitter end renelner wire bundles sanurieg fuel line nu engines tanks anrepping thIngs toaenher plus mnra Can ha reuced vera aoarnlsed Mesanres 1/9 3175 uml X 4 tO twl Package often 40L210Aue Wrap N Ties pkg 10$79 j Are tired uf breaking plentin props hone use no get top performeane out l/2A pattern pylon lob Weve soloed problem making anolleble whet 112A fliers hove long awaited top quality high per formonne tibarglaso 6 n 3 propl Ucars indicate get tan times tho life out fiberglass over plastic wood prop anonomlvel bargain plus sen get nup per formance TO Put t/2A rigltt sway end notice diffarencol 37K lOBAce Bs 3 Fiborglats Propalas Radio Technique/Myers continued page 9 proposed Section 9547 b author izes continued use RC 27 MHz frequencies shared radioteleph ony may work some remote areas thats Legalizing shared useage same thing eliminating because RC flier will hurt dont see much point protesting what think should seek compen sation form assignment exclu TO SERVO--a FUEL LINE 0 Fuel Shut-Off dual-function shut-off used conjunction penbiadder fuel systems allows manual control flow wire protrudes through fuselage positive air borne shut-off connecting lightweight cable down elevator arm servo Made nylon tempered steel spring weighs 1/10th oz Mounting screws sample tubing included $350 price Cooney Tool 4040 24th Ave. Forest Grove OR 97116 sive RC channels elsewhere fre quency spectrum several public service channels 32- 42-MHz band almost abandoned could made available us Conversion existing systems probably wouldnt cost $50 transmitter receiver Docket 20119 released Febru ary 12 1976 holds out hope 100-mw unlicensed operation five frequencies 4982-4990 MHz band 100 mw frequencies will similar per formance 200 mw 27 MHz about what five years ago addition Docket 20282 offers opportunity Application licensing use 54-MHz 6 meter Amateur Radio band Most 27-MHz sets easily con vertible band Section 955 1h 10 3 requires frequency-determining circuitry includ ing crystals employed Class D equip ment internal equipment accessible exterior cabi net As read makes Heath Kraft 1976 transmitters illegal un derstand words intended have effect taken combining classes C D thats what say think should protest seek exception Im sure manufacturers will Im told AMA would prefer responses Docket 20120 addressed directly FCC per instructions AMA News section magazine closing date write May 26 1976 An extension possible dont depend Charles Rankin 8 Corral Lane East Northport NY 11731 electronics engineer inveterate tinkerer gad gets Recently Charlie approached meeting LIRCS Long Island [NY] Radio Control Society Inc cir cuit shown Fig 6 Its critical voltage indicator adjustable over range 45 90 volts its little different concept Basically Charlie doesnt like see idiot lightst burning up power have nothing say Therefore circuit arranged keep pilot light extinguished long voltage above critical value voltage drops below preset value pilot light begins flash As voltage drops further light flashes faster Its almost de vice getting worriea about what will voltage has dropped about 25 volts pilot light goes out again Pretty clever built works fine No temperature tests performed theres no reason expect much response anything capacitor select care have something share ideas devices youd like see printed con tact 70 Froeblich Farm Rd Hicksville NY 11801 July1976 81 INTERNAL SWITCH MOUNT FOR NOBLE SWITCH 6 X 3 FIBERGLASS PROP TRIANGLES II ZIP
Edition: Model Aviation - 1976/07
Page Numbers: 8, 9, 81
Batteries Diodes WHILE HELPING friend pick up pieces moved ask him day 3-wire servos low-volt age receivers would operate radio system diode protection battery pack answer simple direct Because dont know what size use install Before beginning step-by-step instructibn little background information may order nicad battery single-point failure item system battery fails system stops operating Batter ies fail two modes Open no current flows through Short no voltage generated current does flow through battery driven other operating batteries Short circuits com mon frequently caused letting battery lie unattended over winter season spends con siderable time 0 volts state dis charge short-circuited cell battery pack will cause system show decreased range shorted cell airborne pack servos will run slower An open cell acts just like switch turns system oW diode device conducts cur rent freely direction ideally opposite direction makes ideal purposes because can connect across battery will conduct same direction battery fear discharging cell accidently See Fig 1 Now shunt cell battery pack Radio Technique George M Myers 9 FIG 1 DIODESHUNTED BATTERY FIG 2 DIODE TEST SETUP BATTERY PACK 100HMSV 10 WATT4- RESISTORVOLTMETER INSTALL DIODES HERE FOR TEST U diode cell can develop open circuit turning system off price service voltage drop caused diode conducting fully-charged airborne pack output voltage will drop about 56 42 VDC cell develops short will drop zero cell develops open circuit course Connecting diode across open cell will restore circuit output about 34 volts missing voltage absorbed diode worst case pack 44 volts will drop 25 volts Now modern receivers will operate voltages around 30 reli ably 3-wire servos will still func tion slowly weakly voltage will allow least chance making good landing after things go sour Pro-Line Electronics 10632 North 21st Ave Suite 11 Phoenix AZ 85029 first use diode-protected battery packs commercially far know still offer Readers desire diode protection unsure ability install own strongly advised buy such packs want blamed problems arising incorrect installations Connecting diode backwards will discharge bat tery should notice problem right away because diode will get hot still buy some sili con diodes rated at least 1 amp 50 volts such 1N4001 Next test diode setup Fig 2 Test diode both ways voltmeter should read about 52 volts no diode connected should read same diode connected card diode diode marked band around body diode diode connected icated voltage should less 08 volts higher voltage seen set diode aside some other use Fig 3 shows World Engines Expert pack diode string assembled fitted groove formed walls cylindrical cells Note flexible wires provided make connections cells done allow some free motion purpose installing cells back pack rigid setup might break Fig 4 shows diodes stalled pack ready reassem bled Note shrink tubing has used insulate bare metal parts Failure can lead short circuits worse condition trying avoid Note also soldering done tabs cells 60/40 rosin-core solder used Acid solder fluxes will ruin pack completely unnecessary 8 Model Aviation Fg 3 World Engines Export battery pack diode string assembled fitted groove formed walls cylindrical cells Diode protection will prevent open cell shutting off system least can get ship safely down because tabs accept solder very easily Avoid large solder buildup wont get cells back case Use 27- 40-watt soldering iron 1/t chisel point soldering Fig 5 schematic diagram diode-protected pack Transmitter packs can should protected same way However some disassembly transmitter will required have slightest doubt ability correctly dont try Open circuits nicad batteries primarily result vibration transmitter isnt subjected much What happens internal connection active material battery separates pretty easy understand consider material spongy mass pressed window-screen type support Its solid metal therefore connec tion can broken down severe vibra tion such can transmitted engine fail protect pack foam rubber everyone tells you should subject Id like mention flying buddy ran some rather severe vibration tests manufacturers cell could find test results demonstrated thing conclusively foam rubber essen tial Theres no vibration-proof battery available time Citizens Radio Service provides totally inadequate 23 channels use 200000000 citizens put way emphasize problem Sure know band used mis-used types citizens both law-abiding outlaws Nonetheless service inadequate also beyond ability FCC control Personally stopped using 27-MHz band 1970 could no longer tolerate inter ferences illegal kilowatt amplifiers 5watt Walkie-Talkies using RC crystals legal powerful transmitters Navy Special Devices Center Sands Point NY barely 20 miles away Other folks continue use band satisfactorily above will become academic FCC Docket 20120 released March 29 1976 adopted unchanged docu ment intended elicit comments industry public Replies due May 26 1976 Simply stated FCC proposes take away five RC fre quencies 27-MHz band Using frequencles others present Class D service will yield about 100 CR channels through magic single-sideband operation changes will bring about promise obso lete existing CR transreceiver put several thousand land mobile stations out service require modification thousands RC systems can see move taken light ly however interim move purposes providing immediate relief users Citizens Radio Service FCC also considering moving Citizens Radio Service 220 MHz 900 MHz order elimi nate skip-chasing becomes popular illegal pastime among CR opera tors during periods high sunspot activ ity RC systems could benefit such move because would operate satisfactorily much shorter airborne antennas simpler receivers continued page 8 r MV5023 RED 220 OHMS 3 V 01 PF 4 1N4001 4L2vr4 NICAD BATTERIES 4 FIG 5 SCHEMATIC DIAGRAM OF DIODE-PROTECTED PACK S 1 7 6 211 22 MF 15VDC S TO 12VDC 0 33K 1N751 K p10K 0 VOLTS July1976 9 Fig 4 diodes shown installed Wt Expert pack ready reassembly Flex ible wires provided connections cellsheat-shrink tubing used insulate bare metal parts NE 555 FIG 6 ADJUSTABLE CRITICAL VOLTAGE INDICATOR simple inexpensive sturdy internal switnh mnunt install sin jiffy dnuble sided nape en fuse sidO/fnrmar nr bantam junvtlnn Nn drilling nr homing ewkward erats Takes up wunh less mum nthar similar mnunneperfect fnr emaIl planes Fnr Nable Switchnraf nr ndter switch 1 Sn I/B between meunting 4OL20gAna Nnble Infernal SwItch Mnunt $89 Please send complete catalog Enclosed 8100 refunded first order Add 850 1st class null return add $100 handling other rs Like Enilders Triangles Triangles II era enanhar handy mnrkshep aid whiub ynull find indIspensable triangles hane has nan thumb tank thant Se building surtaus end hate Inettet jig fee fun age tonntruntinn Also bane immediately salfeliga leg terminal ynu eacured ofe perpandinular rudder glu Ito stab--the tamer tho triangle removed glue jaint filer Isnt disturbed made aluminum durability plot makat nhem anne straight edge fur cutting Enary wnrkshop needs pair 31 LBAve Triangles II nec pair 5550 SAME ADDRESS STATE ACE WRAP N TIES Nylga strop tighten dawn wont gusts up Handy fur uses Organlalna transmitter end renelner wire bundles sanurieg fuel line nu engines tanks anrepping thIngs toaenher plus mnra Can ha reuced vera aoarnlsed Mesanres 1/9 3175 uml X 4 tO twl Package often 40L210Aue Wrap N Ties pkg 10$79 j Are tired uf breaking plentin props hone use no get top performeane out l/2A pattern pylon lob Weve soloed problem making anolleble whet 112A fliers hove long awaited top quality high per formonne tibarglaso 6 n 3 propl Ucars indicate get tan times tho life out fiberglass over plastic wood prop anonomlvel bargain plus sen get nup per formance TO Put t/2A rigltt sway end notice diffarencol 37K lOBAce Bs 3 Fiborglats Propalas Radio Technique/Myers continued page 9 proposed Section 9547 b author izes continued use RC 27 MHz frequencies shared radioteleph ony may work some remote areas thats Legalizing shared useage same thing eliminating because RC flier will hurt dont see much point protesting what think should seek compen sation form assignment exclu TO SERVO--a FUEL LINE 0 Fuel Shut-Off dual-function shut-off used conjunction penbiadder fuel systems allows manual control flow wire protrudes through fuselage positive air borne shut-off connecting lightweight cable down elevator arm servo Made nylon tempered steel spring weighs 1/10th oz Mounting screws sample tubing included $350 price Cooney Tool 4040 24th Ave. Forest Grove OR 97116 sive RC channels elsewhere fre quency spectrum several public service channels 32- 42-MHz band almost abandoned could made available us Conversion existing systems probably wouldnt cost $50 transmitter receiver Docket 20119 released Febru ary 12 1976 holds out hope 100-mw unlicensed operation five frequencies 4982-4990 MHz band 100 mw frequencies will similar per formance 200 mw 27 MHz about what five years ago addition Docket 20282 offers opportunity Application licensing use 54-MHz 6 meter Amateur Radio band Most 27-MHz sets easily con vertible band Section 955 1h 10 3 requires frequency-determining circuitry includ ing crystals employed Class D equip ment internal equipment accessible exterior cabi net As read makes Heath Kraft 1976 transmitters illegal un derstand words intended have effect taken combining classes C D thats what say think should protest seek exception Im sure manufacturers will Im told AMA would prefer responses Docket 20120 addressed directly FCC per instructions AMA News section magazine closing date write May 26 1976 An extension possible dont depend Charles Rankin 8 Corral Lane East Northport NY 11731 electronics engineer inveterate tinkerer gad gets Recently Charlie approached meeting LIRCS Long Island [NY] Radio Control Society Inc cir cuit shown Fig 6 Its critical voltage indicator adjustable over range 45 90 volts its little different concept Basically Charlie doesnt like see idiot lightst burning up power have nothing say Therefore circuit arranged keep pilot light extinguished long voltage above critical value voltage drops below preset value pilot light begins flash As voltage drops further light flashes faster Its almost de vice getting worriea about what will voltage has dropped about 25 volts pilot light goes out again Pretty clever built works fine No temperature tests performed theres no reason expect much response anything capacitor select care have something share ideas devices youd like see printed con tact 70 Froeblich Farm Rd Hicksville NY 11801 July1976 81 INTERNAL SWITCH MOUNT FOR NOBLE SWITCH 6 X 3 FIBERGLASS PROP TRIANGLES II ZIP
Edition: Model Aviation - 1976/07
Page Numbers: 8, 9, 81
Batteries Diodes WHILE HELPING friend pick up pieces moved ask him day 3-wire servos low-volt age receivers would operate radio system diode protection battery pack answer simple direct Because dont know what size use install Before beginning step-by-step instructibn little background information may order nicad battery single-point failure item system battery fails system stops operating Batter ies fail two modes Open no current flows through Short no voltage generated current does flow through battery driven other operating batteries Short circuits com mon frequently caused letting battery lie unattended over winter season spends con siderable time 0 volts state dis charge short-circuited cell battery pack will cause system show decreased range shorted cell airborne pack servos will run slower An open cell acts just like switch turns system oW diode device conducts cur rent freely direction ideally opposite direction makes ideal purposes because can connect across battery will conduct same direction battery fear discharging cell accidently See Fig 1 Now shunt cell battery pack Radio Technique George M Myers 9 FIG 1 DIODESHUNTED BATTERY FIG 2 DIODE TEST SETUP BATTERY PACK 100HMSV 10 WATT4- RESISTORVOLTMETER INSTALL DIODES HERE FOR TEST U diode cell can develop open circuit turning system off price service voltage drop caused diode conducting fully-charged airborne pack output voltage will drop about 56 42 VDC cell develops short will drop zero cell develops open circuit course Connecting diode across open cell will restore circuit output about 34 volts missing voltage absorbed diode worst case pack 44 volts will drop 25 volts Now modern receivers will operate voltages around 30 reli ably 3-wire servos will still func tion slowly weakly voltage will allow least chance making good landing after things go sour Pro-Line Electronics 10632 North 21st Ave Suite 11 Phoenix AZ 85029 first use diode-protected battery packs commercially far know still offer Readers desire diode protection unsure ability install own strongly advised buy such packs want blamed problems arising incorrect installations Connecting diode backwards will discharge bat tery should notice problem right away because diode will get hot still buy some sili con diodes rated at least 1 amp 50 volts such 1N4001 Next test diode setup Fig 2 Test diode both ways voltmeter should read about 52 volts no diode connected should read same diode connected card diode diode marked band around body diode diode connected icated voltage should less 08 volts higher voltage seen set diode aside some other use Fig 3 shows World Engines Expert pack diode string assembled fitted groove formed walls cylindrical cells Note flexible wires provided make connections cells done allow some free motion purpose installing cells back pack rigid setup might break Fig 4 shows diodes stalled pack ready reassem bled Note shrink tubing has used insulate bare metal parts Failure can lead short circuits worse condition trying avoid Note also soldering done tabs cells 60/40 rosin-core solder used Acid solder fluxes will ruin pack completely unnecessary 8 Model Aviation Fg 3 World Engines Export battery pack diode string assembled fitted groove formed walls cylindrical cells Diode protection will prevent open cell shutting off system least can get ship safely down because tabs accept solder very easily Avoid large solder buildup wont get cells back case Use 27- 40-watt soldering iron 1/t chisel point soldering Fig 5 schematic diagram diode-protected pack Transmitter packs can should protected same way However some disassembly transmitter will required have slightest doubt ability correctly dont try Open circuits nicad batteries primarily result vibration transmitter isnt subjected much What happens internal connection active material battery separates pretty easy understand consider material spongy mass pressed window-screen type support Its solid metal therefore connec tion can broken down severe vibra tion such can transmitted engine fail protect pack foam rubber everyone tells you should subject Id like mention flying buddy ran some rather severe vibration tests manufacturers cell could find test results demonstrated thing conclusively foam rubber essen tial Theres no vibration-proof battery available time Citizens Radio Service provides totally inadequate 23 channels use 200000000 citizens put way emphasize problem Sure know band used mis-used types citizens both law-abiding outlaws Nonetheless service inadequate also beyond ability FCC control Personally stopped using 27-MHz band 1970 could no longer tolerate inter ferences illegal kilowatt amplifiers 5watt Walkie-Talkies using RC crystals legal powerful transmitters Navy Special Devices Center Sands Point NY barely 20 miles away Other folks continue use band satisfactorily above will become academic FCC Docket 20120 released March 29 1976 adopted unchanged docu ment intended elicit comments industry public Replies due May 26 1976 Simply stated FCC proposes take away five RC fre quencies 27-MHz band Using frequencles others present Class D service will yield about 100 CR channels through magic single-sideband operation changes will bring about promise obso lete existing CR transreceiver put several thousand land mobile stations out service require modification thousands RC systems can see move taken light ly however interim move purposes providing immediate relief users Citizens Radio Service FCC also considering moving Citizens Radio Service 220 MHz 900 MHz order elimi nate skip-chasing becomes popular illegal pastime among CR opera tors during periods high sunspot activ ity RC systems could benefit such move because would operate satisfactorily much shorter airborne antennas simpler receivers continued page 8 r MV5023 RED 220 OHMS 3 V 01 PF 4 1N4001 4L2vr4 NICAD BATTERIES 4 FIG 5 SCHEMATIC DIAGRAM OF DIODE-PROTECTED PACK S 1 7 6 211 22 MF 15VDC S TO 12VDC 0 33K 1N751 K p10K 0 VOLTS July1976 9 Fig 4 diodes shown installed Wt Expert pack ready reassembly Flex ible wires provided connections cellsheat-shrink tubing used insulate bare metal parts NE 555 FIG 6 ADJUSTABLE CRITICAL VOLTAGE INDICATOR simple inexpensive sturdy internal switnh mnunt install sin jiffy dnuble sided nape en fuse sidO/fnrmar nr bantam junvtlnn Nn drilling nr homing ewkward erats Takes up wunh less mum nthar similar mnunneperfect fnr emaIl planes Fnr Nable Switchnraf nr ndter switch 1 Sn I/B between meunting 4OL20gAna Nnble Infernal SwItch Mnunt $89 Please send complete catalog Enclosed 8100 refunded first order Add 850 1st class null return add $100 handling other rs Like Enilders Triangles Triangles II era enanhar handy mnrkshep aid whiub ynull find indIspensable triangles hane has nan thumb tank thant Se building surtaus end hate Inettet jig fee fun age tonntruntinn Also bane immediately salfeliga leg terminal ynu eacured ofe perpandinular rudder glu Ito stab--the tamer tho triangle removed glue jaint filer Isnt disturbed made aluminum durability plot makat nhem anne straight edge fur cutting Enary wnrkshop needs pair 31 LBAve Triangles II nec pair 5550 SAME ADDRESS STATE ACE WRAP N TIES Nylga strop tighten dawn wont gusts up Handy fur uses Organlalna transmitter end renelner wire bundles sanurieg fuel line nu engines tanks anrepping thIngs toaenher plus mnra Can ha reuced vera aoarnlsed Mesanres 1/9 3175 uml X 4 tO twl Package often 40L210Aue Wrap N Ties pkg 10$79 j Are tired uf breaking plentin props hone use no get top performeane out l/2A pattern pylon lob Weve soloed problem making anolleble whet 112A fliers hove long awaited top quality high per formonne tibarglaso 6 n 3 propl Ucars indicate get tan times tho life out fiberglass over plastic wood prop anonomlvel bargain plus sen get nup per formance TO Put t/2A rigltt sway end notice diffarencol 37K lOBAce Bs 3 Fiborglats Propalas Radio Technique/Myers continued page 9 proposed Section 9547 b author izes continued use RC 27 MHz frequencies shared radioteleph ony may work some remote areas thats Legalizing shared useage same thing eliminating because RC flier will hurt dont see much point protesting what think should seek compen sation form assignment exclu TO SERVO--a FUEL LINE 0 Fuel Shut-Off dual-function shut-off used conjunction penbiadder fuel systems allows manual control flow wire protrudes through fuselage positive air borne shut-off connecting lightweight cable down elevator arm servo Made nylon tempered steel spring weighs 1/10th oz Mounting screws sample tubing included $350 price Cooney Tool 4040 24th Ave. Forest Grove OR 97116 sive RC channels elsewhere fre quency spectrum several public service channels 32- 42-MHz band almost abandoned could made available us Conversion existing systems probably wouldnt cost $50 transmitter receiver Docket 20119 released Febru ary 12 1976 holds out hope 100-mw unlicensed operation five frequencies 4982-4990 MHz band 100 mw frequencies will similar per formance 200 mw 27 MHz about what five years ago addition Docket 20282 offers opportunity Application licensing use 54-MHz 6 meter Amateur Radio band Most 27-MHz sets easily con vertible band Section 955 1h 10 3 requires frequency-determining circuitry includ ing crystals employed Class D equip ment internal equipment accessible exterior cabi net As read makes Heath Kraft 1976 transmitters illegal un derstand words intended have effect taken combining classes C D thats what say think should protest seek exception Im sure manufacturers will Im told AMA would prefer responses Docket 20120 addressed directly FCC per instructions AMA News section magazine closing date write May 26 1976 An extension possible dont depend Charles Rankin 8 Corral Lane East Northport NY 11731 electronics engineer inveterate tinkerer gad gets Recently Charlie approached meeting LIRCS Long Island [NY] Radio Control Society Inc cir cuit shown Fig 6 Its critical voltage indicator adjustable over range 45 90 volts its little different concept Basically Charlie doesnt like see idiot lightst burning up power have nothing say Therefore circuit arranged keep pilot light extinguished long voltage above critical value voltage drops below preset value pilot light begins flash As voltage drops further light flashes faster Its almost de vice getting worriea about what will voltage has dropped about 25 volts pilot light goes out again Pretty clever built works fine No temperature tests performed theres no reason expect much response anything capacitor select care have something share ideas devices youd like see printed con tact 70 Froeblich Farm Rd Hicksville NY 11801 July1976 81 INTERNAL SWITCH MOUNT FOR NOBLE SWITCH 6 X 3 FIBERGLASS PROP TRIANGLES II ZIP