George Myers 7adiomchnque ABSTRACT Narrow-band transmitter NPRM dis cussed Lead-acid battery charging Correction October 1990 issue MA ran schematic illustrating boost power servos plugging second battery receiver pix PC board okay callout wasnt Its postive land should cutEd Narrow band 93 long-awaited NPRM FCC Notice Proposed Rule Making regarding narrow-band transmitters RC systems has fi nally published So does affect have greatly simplified language il lustrate changes Type Acceptance criteria prior March 1 1993 Wideband Maximum Sideband Power kP dB Frequency precision % about 3600 Hz Type Acceptance criteria after March 1 1993 Narrow band Maximum Sideband Power -56 kP dB Frequency precision % about Hz can see maximum permitted power interference-producing transmitter sidebands must reduced about 13 dB kP refers additional reduction propor tional power transmitter Since RC transmitters have about same power effect kP reduction will relatively moderate equitable fliers will however re duce sidebands high-powered PRS sta tions between channels 10 kHz away Safer flying conditions coming Frequency tolerance has narrowed 60% need greater precision narrowband environment Incidents traceable offfrequency transmitters should diminish Summary proposed changes 1 Import US manufacture wideband transmitters ends March 1 1992 2 US sales wideband transmitters ends March 1 1993 3 Through March 1 1993 0005% XTALS may sold RC systems 4 After March 1 1993 0002% XTALS will required RC systems 5 Wideband RC transmitters service before March 1 1993 may used afterward grandfather clause lets use old equipment long works Ref NPRM RM-6683 RM-6746 PR Docket 90-20554 Most manufacturers foreign domestic have meeting transmitter requirements since 1988 Thats see Gold stickered transmitters around Everybody knows proposed changes will work transmitters conforming can produced economically NPRM creates safe conditions input 50-channel spectrum Obtaining safe output spectrum other matter Note NPRM says nothing about receivers AMA Guidelines membership manual have quite bit say about receivers order make best use what have given will need narrow-band re ceiver Dual-conversion receivers will reject interference can found RC bands Single-conversion receivers can also de signed resist such interference old wideband AM OWBAM single-conversion re ceivers wont particular OWBAM users must now watch out 21M may created pair transmitters 23 channels apart imaging affects RC channels 11 through 14 57 through 60 Prior January 1 1991 AMA phase-in plan blocked out half 50 chan nels avoid 21M imaging known problem OWBAMs During protected period dual-conversion narrowband FM systems have developed brought market up make use FCC planning force Left Sukhol Su-26 acrobatic airplane hottest machine air show circuit Note visibility cockpit size wheels Right Just like helicopter Sukhoi Su-26 can hang its three-bladed counterclockwise-turning propeller 325-hp radial gives machine better vertical performance Radio Control model have seen Sussex New Jersey Air Show April 26 1990 30 Model Aviation 70 Froeblich Farm Rd Hlcksvllle NY 11801 may look like Saipan 1945 its actually MacArthur Airport islip NY 1990 Fifi last flying 5-29 belongs Confederate Air Force air show fliers CaRa standard chargers use leadacid wet geiled-electrolyte batteries Batter ies last longer use CaRa charger See text order change fact NPRM specifically autho rizes continued use OWBAMs friends want use some type arrangement avoids modeler-to-modeler interference go ahead can use unstickered OWBAM transmitter club field long club will accommo date what happens fly public facility us very likely AMA mem bership will required insurance AMA Safety Code will posted en forced first entry under Safety Code Insur ance 1990 membership manual reads follows Model flying must accordance code order AMA liability protec tion apply think its likely informed public author ity will soon require use narrow-band equipment within parkgrounds can follow line reasoning cant Narrow-band equipment available safer Safer equip ment wont cost Parks Commissioner thing will make flying less likely gener ate lawsuits require Item Three Safety Code states established will abide safety rules flying site use ow have interest ing situation fly public park narrow-band equipment required use OWBAM have accident will violation park rules also will AMA liability protection See works OWBAMs may legal remain ing days few numbered opinion should modify narrow bandor wear out soon Lead-acid batteries Previous columns have dis cussed charging nickel-cadmium batteries month Ill discuss lead-acid cells acid used sulfuric acid very corrosive can tell what kind cell have mea suring voltage fully charged cell shows 22 volts open circuit no-load test cell lead-acid type cell has remov able cover must add distilled water time time make up water dis sociated hydrogen oxygen charg ing process gases explosive lead-acid charging site must well ventilated cell doesnt have removable covers sealed cell may contain gelled electro lyte dont have cant add water sealed cell big advantage sealed leadacid battery wont find corrosion un expected placesor holes garments after washed discharge characteristic lead-acid cell shows shallow slope terminal voltage falling about 8% 80% charge de pleted Voltage flattest part curve affected discharge rate cell dis charged C/l0 10-hour rate voltage will start 22 VDC per cell usable capacity will approximately value marked case eg 12 ampere-hours discharge done C one-hour rate voltage will start about 21 VDC per cell available capacity will about 70% 84 ampere-hours Raising discharge current lOC six-minute rate drops starting volt age 185 VDC per cell available capac ity about 35% 42 ampere-hours rate Thats automobile batteries rated both total capacity cranking amps lost ca pacity isnt really lost want recover must discharge cell lower rate Small lead-acid batteries frequently used start model airplane engines electric starter motors used can easily draw 30 amps working against stiff flooded engine So can see should pick battery large enough job common see lead-acid batteries auto mobiles electric-powered vehicles like golf carts because theyre cheaper nickelcadmium batteries provide same service can kept charged other hand its com mon see nickel-cadmium batteries used air planes freedom necessity charging lack corrosion problems important considerations Ni-Cds per fect model airplanes because arent dam aged neglect way lead-acid batteries Retained capacity strongly affected tem perature freezing point 32 0F 0 0C leadacid charge storage time about year 1400F 600C unreasonable tem perature see inside trunk car charge storage time drops about four days discharge point taken 198 volts per cell open circuit no-load room temper ature should remember number cause cant suck out gelled electrolyte measure its specific gravity can wet lead-acid cells important keep lead-acid batteries charged because letting cell voltage drop low 18 VDC per cell causes permanent cell dam age Overcharging regular rate C/b can permanently damage lead-acid cells Lead-acid cells arent tolerant nickel cadmium cells abuse As nickel-cadmium battery chargers market offers large variety charger types Continued page 110 December 1990 31 AIR WOLF EPOXY FIBERGLASS FUSELAGE S TAKES MOST 50-60 MECHANICS OTHER MODELS AVAILABLE LARRY JOLLY MODEL PRODUCTS $21000 5501 WCOMO SANTA ANA CALIFORNIA 92703 714 826-6861 Z ty/Preston Continued page 25 Battle Britain No doubt aware 1990 marks 50th anniversary Battle Britain Im sure watched recent Masterpiece Theatre production Piece Cake some outstanding aerial shots WW II aircraft So story wasnt hotso what have just learned coming weekend September 8-9 will Spitfire 109 Manassas Airport close Wash ington DC Unfortunately will get see beauties since American Airlines co operates will cruising aboard 42-ft sail boat Caribbean So now know months column has lot non-safety-related material due before due leave pre cious little time write Labor Day being spent front word processor hope others fortunate out fly ing model pterodactyls I When responding advertisers mention read about ModelAviation Radio Technique/Myers Continued page 31 remember father owned service station dispenser gasoline grease jobs 1930s charger consisted selenium rectifier light bulb rectifier converted AC DC light bulb regulated cur rent put battery battery discharged bulb glowed brightly showed high resistance limiting current went battery battery became fully charged light went Out current battery re duced trickle wondered about time later realized Dads charger ba sically constant-voltage type voltage chosen produce trickle charge charged batteries can still buy Dads charger local Sears store packed up neat steel box handle leads directly CaRa 12-volt automa tic charger standard model de signed charge lead-acid batteries capaci ties six 12 ampere-hour range heavyduty model 2 25 amp available Sail plane winch batteries electric-powered plane mass-charger batteries etc plug either 110 VAC leave connected bat tery whenever latter use will auto matically restore charge hold battery constant state readiness 132 VDC room temperature Both models available pre adjusted hold constant 132 VDC Wet motor cycle batteries extremely variable instruc tions included matching charger whatever ha-ye Either charger can ised properly sized 12-volt read-acid batterywet main tenance-free seled gdled electrolyte types water level wet cells should checked six montss though will notice pulsed charge-Irilding current CaRa dissociates less water battery constant-current trickle charger can testify personal experience gelled cells will last longer charger other types Again have six years experi ence GelCellTe CaRa charger lot got first GelCells constant-current charger have same six years experience motorcycle bat tery CaRa charger Ive keep adding water Ive noticed add less water case constantcurrent charger CaRa automatic 12-volt charger puts Out Continued page 114 BALSA WOOD 6Y1Wi48 TIT T7 W1 1/8 912 BALSA WOOD1/83/161216 STiCKS1/8 1/41418 1/8 3/81722 1/18-INcH364 1/8 1/21828 1/16 1116091/8 3142635 1/I6 07 1/16 1/809 1/16 10 1/161/411 1/18 3/814 1116 1/217 1/183/422 3/16-INcH3848 12 143/163/161418 163/18 1/41620 183/163/81722 213/16 1/22127 303/16 3/43041 3/32-INcH3648 1/4INcH3648 3/323/3209121/4 1/41722 3/32 1/810141/43/81927 3/323/1611181/4 1/22231 3/32 1/414171/4 3/43445 3/323/81020 3/321/21722 3/32 533 * Ocuble BIa W,4 Price Pr Spruce ,d 8a,44d Slick 1/8INCH3648 3/8INcH3648 3/8 rr 3/82940 3/8 1/23344 3/8 784 1/2INcH3848 1/21/24052 1/2 3/45875 TRIANGULAR CUT BALSA 1/4 1/43627 3/83/83631 1/2 1/23640 3/4 3650 113665 BALSA PLANKS 3/4336190 1236179 1336248 5/18INcH38481 Ir 4 36324 _____________ 2236 246 5/165/1623282336302 5/183/825322436498 5/161/230393336524 5/163/442563436728 EN ALSA SHEETS 1-INcH3648 1/16 9 3/32 3 1/8 13547 3/18 2 1/414481 3/8 15777 1/2 17094 2INcH3648 1/32 3 1/1623951 3/32 8 1/8 24984 3/1625877 1/4 28790 3/8282110 1/22121181 3-INcH3648 1/3234357 1/1634882 3/32 0 1/836486 3/16 377102 1/4390120 9/163110143 3/83128171 1/23161214 4INcH3648 1/32 3 1/16478108 3/32488117 1/84102135 3/164122162 1/44140207 3/84195290 1/2 348 1/461277 1/4 12 12198 1/4 1224314 1/4 1248626 3/81212193 3/8 12 24385 3/8 1248770 1/2 12 12218 1/2 1224433 1/2 1248885 1/64 12 12195 1/64 12 24389 1/64 1248801 1/6448483204 1/3261264 1/32 12 12127 1/32 1224257 1/32 1248506 1/1661263 1/16 12 12125 1/16 4250 1/16 12 48509 3/3261297 3/321212194 3/32 12 24387 3/32 1248774 1/8612107 1/8 12 12213 1/8 12 24425 TAPERED TRAILING 1/8 1248850 EDGE36 48 3/186 12791/8 1/22432 3/16 12 121563/16 3/43143 3/16x12243141/4 14288 3/161248626 5/16 11/44785 3/8 11/25877 * OPEN TO THE PUBLIC * Superior Aircraft Materials 12020-G Centralia iian Gardens California 90716 865-3220 Handling Charge -$500 $350 C0D mum Order $2000 plus UPS accept Personal checks COD fornia Residents add 6% Sales Tax LITE PLYWOOD 1/8121282 1/81224184 1/8 1248328 110 Model Aviation TAIBI BIRCH PLYWOOD FROM WEST COAST ENGINES FULLY ADJUSTABLE ENGINE MOUNTS -NO DRILLINGFor 35 80 Size 2 Cycle Engines INTRODUCTORY SPECIAL$1995 Extruded 6061 Aluminum Fits Most Planes Perfect Test Stand Jack Screw Clamping Positive Holding Fits Medium 4-Strokes ENGINE SALE -While LastRossi 90 Front Intake Rossi 91 Rear Intake Webra 80 Ducted Fan Royal 28 ABC Ross Collector $49500 I24 L VISA MASTERCARD DISCOVER 619 951-8349 WEST COAST ENGINES 17080 Bear Valley Rd SteD-3-243 Victorville CA 92392 $13995 $14995 $12995 $6995 continued page 110 pulses charging current measuring battery voltage very precise internal voltmeter tween pulses As battery voltage rises near maximum allowable 132 VDC pulses get shorter off time gets longer producing charge-holding rate just compen sates self-discharge An LED front panel glows steadily just like Dads charger battery contains little charge pulses battery goes charge-holding ad just potentiometer front panzl make light go Out battery fully charged just way Dad did just remembered Dads charger big rheostat could ad justed match fully charged battery voltage adjustment used mainly charge several batteries series Dad kept charger wheeled cart because big heavy clumsy CaRa auto matic 12-volt charger fits hand thanks Ralph Croaning CaRa Gates Battery Manual Both contributed much information column standard rate charger amp six- 12ampere-hour sealed wet batteries costs $4695 plus $3 P&H high-rate charger 2 25 amps winch batteries costs $5895 plus $4 P&H der CaRa Canton SD 57013 Ready 91 /Myers Continued page 43 certainly will lose other users new users will interfere obso lete RC systems keep service Any reasonable person will understand up graded equipment necessary protect investment hobby WHO DOES THE WORK work have send equipment somewhere have serviced have pass word along millions dont belong AMA since wont have opportunity read magazine Let say word favor clubs have open enrollment vite just anybody join club have opportunity exert some control over members have closed membership list have no con trol get blamed transgressions Does really matter made noise lost field flew what pro hibited airspace crashed field gone its gone have outsiders inside club have some control over Theyve got something lose benefit dues paid Two-thirds wont active club anyway according observations club offi cers everywhere main effect membership money club treasury Some money will go newsletter will read fluence will extended main effect having outside club stand have less no effect since may actively resist advice just because ex cluded following firms able test performance transmitters install RCMA/AMA Gold stickers justi fled may also undertake make neces sary alignments surveyed could find kept adding information until magazine deadline Some data probably probably have changed already Beware firms cant install RCMA/AMA sticker phony sticker no sticker can mean no AMA insurance equip ment FCC-legal Ponder LISTED IN ORDER OF RICMA/AMA STICKER NUMBERS Included brief summary ser 114 Model Aviation Airborne Electronic Systems last failsafe battery backup system gives glitch free battery backup allowing continue flying AJI switching fully electronic no relays mechanical switches fail Upon landing once transmitter turned off unit emits loud audible alarm main receiver pack discharged below safe limit system has switched backup mode using optional NiCAD backup packs recharging automatic receiver pack charged Factory Direct $3995 Call free brochure products AES 16055 Caputo Drive Unit D[j[~j an Hill CA 95037 Tel 408 779-4832 K Airborne Watchdog Model AWl -s
Edition: Model Aviation - 1990/12
Page Numbers: 30, 31, 110, 114
George Myers 7adiomchnque ABSTRACT Narrow-band transmitter NPRM dis cussed Lead-acid battery charging Correction October 1990 issue MA ran schematic illustrating boost power servos plugging second battery receiver pix PC board okay callout wasnt Its postive land should cutEd Narrow band 93 long-awaited NPRM FCC Notice Proposed Rule Making regarding narrow-band transmitters RC systems has fi nally published So does affect have greatly simplified language il lustrate changes Type Acceptance criteria prior March 1 1993 Wideband Maximum Sideband Power kP dB Frequency precision % about 3600 Hz Type Acceptance criteria after March 1 1993 Narrow band Maximum Sideband Power -56 kP dB Frequency precision % about Hz can see maximum permitted power interference-producing transmitter sidebands must reduced about 13 dB kP refers additional reduction propor tional power transmitter Since RC transmitters have about same power effect kP reduction will relatively moderate equitable fliers will however re duce sidebands high-powered PRS sta tions between channels 10 kHz away Safer flying conditions coming Frequency tolerance has narrowed 60% need greater precision narrowband environment Incidents traceable offfrequency transmitters should diminish Summary proposed changes 1 Import US manufacture wideband transmitters ends March 1 1992 2 US sales wideband transmitters ends March 1 1993 3 Through March 1 1993 0005% XTALS may sold RC systems 4 After March 1 1993 0002% XTALS will required RC systems 5 Wideband RC transmitters service before March 1 1993 may used afterward grandfather clause lets use old equipment long works Ref NPRM RM-6683 RM-6746 PR Docket 90-20554 Most manufacturers foreign domestic have meeting transmitter requirements since 1988 Thats see Gold stickered transmitters around Everybody knows proposed changes will work transmitters conforming can produced economically NPRM creates safe conditions input 50-channel spectrum Obtaining safe output spectrum other matter Note NPRM says nothing about receivers AMA Guidelines membership manual have quite bit say about receivers order make best use what have given will need narrow-band re ceiver Dual-conversion receivers will reject interference can found RC bands Single-conversion receivers can also de signed resist such interference old wideband AM OWBAM single-conversion re ceivers wont particular OWBAM users must now watch out 21M may created pair transmitters 23 channels apart imaging affects RC channels 11 through 14 57 through 60 Prior January 1 1991 AMA phase-in plan blocked out half 50 chan nels avoid 21M imaging known problem OWBAMs During protected period dual-conversion narrowband FM systems have developed brought market up make use FCC planning force Left Sukhol Su-26 acrobatic airplane hottest machine air show circuit Note visibility cockpit size wheels Right Just like helicopter Sukhoi Su-26 can hang its three-bladed counterclockwise-turning propeller 325-hp radial gives machine better vertical performance Radio Control model have seen Sussex New Jersey Air Show April 26 1990 30 Model Aviation 70 Froeblich Farm Rd Hlcksvllle NY 11801 may look like Saipan 1945 its actually MacArthur Airport islip NY 1990 Fifi last flying 5-29 belongs Confederate Air Force air show fliers CaRa standard chargers use leadacid wet geiled-electrolyte batteries Batter ies last longer use CaRa charger See text order change fact NPRM specifically autho rizes continued use OWBAMs friends want use some type arrangement avoids modeler-to-modeler interference go ahead can use unstickered OWBAM transmitter club field long club will accommo date what happens fly public facility us very likely AMA mem bership will required insurance AMA Safety Code will posted en forced first entry under Safety Code Insur ance 1990 membership manual reads follows Model flying must accordance code order AMA liability protec tion apply think its likely informed public author ity will soon require use narrow-band equipment within parkgrounds can follow line reasoning cant Narrow-band equipment available safer Safer equip ment wont cost Parks Commissioner thing will make flying less likely gener ate lawsuits require Item Three Safety Code states established will abide safety rules flying site use ow have interest ing situation fly public park narrow-band equipment required use OWBAM have accident will violation park rules also will AMA liability protection See works OWBAMs may legal remain ing days few numbered opinion should modify narrow bandor wear out soon Lead-acid batteries Previous columns have dis cussed charging nickel-cadmium batteries month Ill discuss lead-acid cells acid used sulfuric acid very corrosive can tell what kind cell have mea suring voltage fully charged cell shows 22 volts open circuit no-load test cell lead-acid type cell has remov able cover must add distilled water time time make up water dis sociated hydrogen oxygen charg ing process gases explosive lead-acid charging site must well ventilated cell doesnt have removable covers sealed cell may contain gelled electro lyte dont have cant add water sealed cell big advantage sealed leadacid battery wont find corrosion un expected placesor holes garments after washed discharge characteristic lead-acid cell shows shallow slope terminal voltage falling about 8% 80% charge de pleted Voltage flattest part curve affected discharge rate cell dis charged C/l0 10-hour rate voltage will start 22 VDC per cell usable capacity will approximately value marked case eg 12 ampere-hours discharge done C one-hour rate voltage will start about 21 VDC per cell available capacity will about 70% 84 ampere-hours Raising discharge current lOC six-minute rate drops starting volt age 185 VDC per cell available capac ity about 35% 42 ampere-hours rate Thats automobile batteries rated both total capacity cranking amps lost ca pacity isnt really lost want recover must discharge cell lower rate Small lead-acid batteries frequently used start model airplane engines electric starter motors used can easily draw 30 amps working against stiff flooded engine So can see should pick battery large enough job common see lead-acid batteries auto mobiles electric-powered vehicles like golf carts because theyre cheaper nickelcadmium batteries provide same service can kept charged other hand its com mon see nickel-cadmium batteries used air planes freedom necessity charging lack corrosion problems important considerations Ni-Cds per fect model airplanes because arent dam aged neglect way lead-acid batteries Retained capacity strongly affected tem perature freezing point 32 0F 0 0C leadacid charge storage time about year 1400F 600C unreasonable tem perature see inside trunk car charge storage time drops about four days discharge point taken 198 volts per cell open circuit no-load room temper ature should remember number cause cant suck out gelled electrolyte measure its specific gravity can wet lead-acid cells important keep lead-acid batteries charged because letting cell voltage drop low 18 VDC per cell causes permanent cell dam age Overcharging regular rate C/b can permanently damage lead-acid cells Lead-acid cells arent tolerant nickel cadmium cells abuse As nickel-cadmium battery chargers market offers large variety charger types Continued page 110 December 1990 31 AIR WOLF EPOXY FIBERGLASS FUSELAGE S TAKES MOST 50-60 MECHANICS OTHER MODELS AVAILABLE LARRY JOLLY MODEL PRODUCTS $21000 5501 WCOMO SANTA ANA CALIFORNIA 92703 714 826-6861 Z ty/Preston Continued page 25 Battle Britain No doubt aware 1990 marks 50th anniversary Battle Britain Im sure watched recent Masterpiece Theatre production Piece Cake some outstanding aerial shots WW II aircraft So story wasnt hotso what have just learned coming weekend September 8-9 will Spitfire 109 Manassas Airport close Wash ington DC Unfortunately will get see beauties since American Airlines co operates will cruising aboard 42-ft sail boat Caribbean So now know months column has lot non-safety-related material due before due leave pre cious little time write Labor Day being spent front word processor hope others fortunate out fly ing model pterodactyls I When responding advertisers mention read about ModelAviation Radio Technique/Myers Continued page 31 remember father owned service station dispenser gasoline grease jobs 1930s charger consisted selenium rectifier light bulb rectifier converted AC DC light bulb regulated cur rent put battery battery discharged bulb glowed brightly showed high resistance limiting current went battery battery became fully charged light went Out current battery re duced trickle wondered about time later realized Dads charger ba sically constant-voltage type voltage chosen produce trickle charge charged batteries can still buy Dads charger local Sears store packed up neat steel box handle leads directly CaRa 12-volt automa tic charger standard model de signed charge lead-acid batteries capaci ties six 12 ampere-hour range heavyduty model 2 25 amp available Sail plane winch batteries electric-powered plane mass-charger batteries etc plug either 110 VAC leave connected bat tery whenever latter use will auto matically restore charge hold battery constant state readiness 132 VDC room temperature Both models available pre adjusted hold constant 132 VDC Wet motor cycle batteries extremely variable instruc tions included matching charger whatever ha-ye Either charger can ised properly sized 12-volt read-acid batterywet main tenance-free seled gdled electrolyte types water level wet cells should checked six montss though will notice pulsed charge-Irilding current CaRa dissociates less water battery constant-current trickle charger can testify personal experience gelled cells will last longer charger other types Again have six years experi ence GelCellTe CaRa charger lot got first GelCells constant-current charger have same six years experience motorcycle bat tery CaRa charger Ive keep adding water Ive noticed add less water case constantcurrent charger CaRa automatic 12-volt charger puts Out Continued page 114 BALSA WOOD 6Y1Wi48 TIT T7 W1 1/8 912 BALSA WOOD1/83/161216 STiCKS1/8 1/41418 1/8 3/81722 1/18-INcH364 1/8 1/21828 1/16 1116091/8 3142635 1/I6 07 1/16 1/809 1/16 10 1/161/411 1/18 3/814 1116 1/217 1/183/422 3/16-INcH3848 12 143/163/161418 163/18 1/41620 183/163/81722 213/16 1/22127 303/16 3/43041 3/32-INcH3648 1/4INcH3648 3/323/3209121/4 1/41722 3/32 1/810141/43/81927 3/323/1611181/4 1/22231 3/32 1/414171/4 3/43445 3/323/81020 3/321/21722 3/32 533 * Ocuble BIa W,4 Price Pr Spruce ,d 8a,44d Slick 1/8INCH3648 3/8INcH3648 3/8 rr 3/82940 3/8 1/23344 3/8 784 1/2INcH3848 1/21/24052 1/2 3/45875 TRIANGULAR CUT BALSA 1/4 1/43627 3/83/83631 1/2 1/23640 3/4 3650 113665 BALSA PLANKS 3/4336190 1236179 1336248 5/18INcH38481 Ir 4 36324 _____________ 2236 246 5/165/1623282336302 5/183/825322436498 5/161/230393336524 5/163/442563436728 EN ALSA SHEETS 1-INcH3648 1/16 9 3/32 3 1/8 13547 3/18 2 1/414481 3/8 15777 1/2 17094 2INcH3648 1/32 3 1/1623951 3/32 8 1/8 24984 3/1625877 1/4 28790 3/8282110 1/22121181 3-INcH3648 1/3234357 1/1634882 3/32 0 1/836486 3/16 377102 1/4390120 9/163110143 3/83128171 1/23161214 4INcH3648 1/32 3 1/16478108 3/32488117 1/84102135 3/164122162 1/44140207 3/84195290 1/2 348 1/461277 1/4 12 12198 1/4 1224314 1/4 1248626 3/81212193 3/8 12 24385 3/8 1248770 1/2 12 12218 1/2 1224433 1/2 1248885 1/64 12 12195 1/64 12 24389 1/64 1248801 1/6448483204 1/3261264 1/32 12 12127 1/32 1224257 1/32 1248506 1/1661263 1/16 12 12125 1/16 4250 1/16 12 48509 3/3261297 3/321212194 3/32 12 24387 3/32 1248774 1/8612107 1/8 12 12213 1/8 12 24425 TAPERED TRAILING 1/8 1248850 EDGE36 48 3/186 12791/8 1/22432 3/16 12 121563/16 3/43143 3/16x12243141/4 14288 3/161248626 5/16 11/44785 3/8 11/25877 * OPEN TO THE PUBLIC * Superior Aircraft Materials 12020-G Centralia iian Gardens California 90716 865-3220 Handling Charge -$500 $350 C0D mum Order $2000 plus UPS accept Personal checks COD fornia Residents add 6% Sales Tax LITE PLYWOOD 1/8121282 1/81224184 1/8 1248328 110 Model Aviation TAIBI BIRCH PLYWOOD FROM WEST COAST ENGINES FULLY ADJUSTABLE ENGINE MOUNTS -NO DRILLINGFor 35 80 Size 2 Cycle Engines INTRODUCTORY SPECIAL$1995 Extruded 6061 Aluminum Fits Most Planes Perfect Test Stand Jack Screw Clamping Positive Holding Fits Medium 4-Strokes ENGINE SALE -While LastRossi 90 Front Intake Rossi 91 Rear Intake Webra 80 Ducted Fan Royal 28 ABC Ross Collector $49500 I24 L VISA MASTERCARD DISCOVER 619 951-8349 WEST COAST ENGINES 17080 Bear Valley Rd SteD-3-243 Victorville CA 92392 $13995 $14995 $12995 $6995 continued page 110 pulses charging current measuring battery voltage very precise internal voltmeter tween pulses As battery voltage rises near maximum allowable 132 VDC pulses get shorter off time gets longer producing charge-holding rate just compen sates self-discharge An LED front panel glows steadily just like Dads charger battery contains little charge pulses battery goes charge-holding ad just potentiometer front panzl make light go Out battery fully charged just way Dad did just remembered Dads charger big rheostat could ad justed match fully charged battery voltage adjustment used mainly charge several batteries series Dad kept charger wheeled cart because big heavy clumsy CaRa auto matic 12-volt charger fits hand thanks Ralph Croaning CaRa Gates Battery Manual Both contributed much information column standard rate charger amp six- 12ampere-hour sealed wet batteries costs $4695 plus $3 P&H high-rate charger 2 25 amps winch batteries costs $5895 plus $4 P&H der CaRa Canton SD 57013 Ready 91 /Myers Continued page 43 certainly will lose other users new users will interfere obso lete RC systems keep service Any reasonable person will understand up graded equipment necessary protect investment hobby WHO DOES THE WORK work have send equipment somewhere have serviced have pass word along millions dont belong AMA since wont have opportunity read magazine Let say word favor clubs have open enrollment vite just anybody join club have opportunity exert some control over members have closed membership list have no con trol get blamed transgressions Does really matter made noise lost field flew what pro hibited airspace crashed field gone its gone have outsiders inside club have some control over Theyve got something lose benefit dues paid Two-thirds wont active club anyway according observations club offi cers everywhere main effect membership money club treasury Some money will go newsletter will read fluence will extended main effect having outside club stand have less no effect since may actively resist advice just because ex cluded following firms able test performance transmitters install RCMA/AMA Gold stickers justi fled may also undertake make neces sary alignments surveyed could find kept adding information until magazine deadline Some data probably probably have changed already Beware firms cant install RCMA/AMA sticker phony sticker no sticker can mean no AMA insurance equip ment FCC-legal Ponder LISTED IN ORDER OF RICMA/AMA STICKER NUMBERS Included brief summary ser 114 Model Aviation Airborne Electronic Systems last failsafe battery backup system gives glitch free battery backup allowing continue flying AJI switching fully electronic no relays mechanical switches fail Upon landing once transmitter turned off unit emits loud audible alarm main receiver pack discharged below safe limit system has switched backup mode using optional NiCAD backup packs recharging automatic receiver pack charged Factory Direct $3995 Call free brochure products AES 16055 Caputo Drive Unit D[j[~j an Hill CA 95037 Tel 408 779-4832 K Airborne Watchdog Model AWl -s
Edition: Model Aviation - 1990/12
Page Numbers: 30, 31, 110, 114
George Myers 7adiomchnque ABSTRACT Narrow-band transmitter NPRM dis cussed Lead-acid battery charging Correction October 1990 issue MA ran schematic illustrating boost power servos plugging second battery receiver pix PC board okay callout wasnt Its postive land should cutEd Narrow band 93 long-awaited NPRM FCC Notice Proposed Rule Making regarding narrow-band transmitters RC systems has fi nally published So does affect have greatly simplified language il lustrate changes Type Acceptance criteria prior March 1 1993 Wideband Maximum Sideband Power kP dB Frequency precision % about 3600 Hz Type Acceptance criteria after March 1 1993 Narrow band Maximum Sideband Power -56 kP dB Frequency precision % about Hz can see maximum permitted power interference-producing transmitter sidebands must reduced about 13 dB kP refers additional reduction propor tional power transmitter Since RC transmitters have about same power effect kP reduction will relatively moderate equitable fliers will however re duce sidebands high-powered PRS sta tions between channels 10 kHz away Safer flying conditions coming Frequency tolerance has narrowed 60% need greater precision narrowband environment Incidents traceable offfrequency transmitters should diminish Summary proposed changes 1 Import US manufacture wideband transmitters ends March 1 1992 2 US sales wideband transmitters ends March 1 1993 3 Through March 1 1993 0005% XTALS may sold RC systems 4 After March 1 1993 0002% XTALS will required RC systems 5 Wideband RC transmitters service before March 1 1993 may used afterward grandfather clause lets use old equipment long works Ref NPRM RM-6683 RM-6746 PR Docket 90-20554 Most manufacturers foreign domestic have meeting transmitter requirements since 1988 Thats see Gold stickered transmitters around Everybody knows proposed changes will work transmitters conforming can produced economically NPRM creates safe conditions input 50-channel spectrum Obtaining safe output spectrum other matter Note NPRM says nothing about receivers AMA Guidelines membership manual have quite bit say about receivers order make best use what have given will need narrow-band re ceiver Dual-conversion receivers will reject interference can found RC bands Single-conversion receivers can also de signed resist such interference old wideband AM OWBAM single-conversion re ceivers wont particular OWBAM users must now watch out 21M may created pair transmitters 23 channels apart imaging affects RC channels 11 through 14 57 through 60 Prior January 1 1991 AMA phase-in plan blocked out half 50 chan nels avoid 21M imaging known problem OWBAMs During protected period dual-conversion narrowband FM systems have developed brought market up make use FCC planning force Left Sukhol Su-26 acrobatic airplane hottest machine air show circuit Note visibility cockpit size wheels Right Just like helicopter Sukhoi Su-26 can hang its three-bladed counterclockwise-turning propeller 325-hp radial gives machine better vertical performance Radio Control model have seen Sussex New Jersey Air Show April 26 1990 30 Model Aviation 70 Froeblich Farm Rd Hlcksvllle NY 11801 may look like Saipan 1945 its actually MacArthur Airport islip NY 1990 Fifi last flying 5-29 belongs Confederate Air Force air show fliers CaRa standard chargers use leadacid wet geiled-electrolyte batteries Batter ies last longer use CaRa charger See text order change fact NPRM specifically autho rizes continued use OWBAMs friends want use some type arrangement avoids modeler-to-modeler interference go ahead can use unstickered OWBAM transmitter club field long club will accommo date what happens fly public facility us very likely AMA mem bership will required insurance AMA Safety Code will posted en forced first entry under Safety Code Insur ance 1990 membership manual reads follows Model flying must accordance code order AMA liability protec tion apply think its likely informed public author ity will soon require use narrow-band equipment within parkgrounds can follow line reasoning cant Narrow-band equipment available safer Safer equip ment wont cost Parks Commissioner thing will make flying less likely gener ate lawsuits require Item Three Safety Code states established will abide safety rules flying site use ow have interest ing situation fly public park narrow-band equipment required use OWBAM have accident will violation park rules also will AMA liability protection See works OWBAMs may legal remain ing days few numbered opinion should modify narrow bandor wear out soon Lead-acid batteries Previous columns have dis cussed charging nickel-cadmium batteries month Ill discuss lead-acid cells acid used sulfuric acid very corrosive can tell what kind cell have mea suring voltage fully charged cell shows 22 volts open circuit no-load test cell lead-acid type cell has remov able cover must add distilled water time time make up water dis sociated hydrogen oxygen charg ing process gases explosive lead-acid charging site must well ventilated cell doesnt have removable covers sealed cell may contain gelled electro lyte dont have cant add water sealed cell big advantage sealed leadacid battery wont find corrosion un expected placesor holes garments after washed discharge characteristic lead-acid cell shows shallow slope terminal voltage falling about 8% 80% charge de pleted Voltage flattest part curve affected discharge rate cell dis charged C/l0 10-hour rate voltage will start 22 VDC per cell usable capacity will approximately value marked case eg 12 ampere-hours discharge done C one-hour rate voltage will start about 21 VDC per cell available capacity will about 70% 84 ampere-hours Raising discharge current lOC six-minute rate drops starting volt age 185 VDC per cell available capac ity about 35% 42 ampere-hours rate Thats automobile batteries rated both total capacity cranking amps lost ca pacity isnt really lost want recover must discharge cell lower rate Small lead-acid batteries frequently used start model airplane engines electric starter motors used can easily draw 30 amps working against stiff flooded engine So can see should pick battery large enough job common see lead-acid batteries auto mobiles electric-powered vehicles like golf carts because theyre cheaper nickelcadmium batteries provide same service can kept charged other hand its com mon see nickel-cadmium batteries used air planes freedom necessity charging lack corrosion problems important considerations Ni-Cds per fect model airplanes because arent dam aged neglect way lead-acid batteries Retained capacity strongly affected tem perature freezing point 32 0F 0 0C leadacid charge storage time about year 1400F 600C unreasonable tem perature see inside trunk car charge storage time drops about four days discharge point taken 198 volts per cell open circuit no-load room temper ature should remember number cause cant suck out gelled electrolyte measure its specific gravity can wet lead-acid cells important keep lead-acid batteries charged because letting cell voltage drop low 18 VDC per cell causes permanent cell dam age Overcharging regular rate C/b can permanently damage lead-acid cells Lead-acid cells arent tolerant nickel cadmium cells abuse As nickel-cadmium battery chargers market offers large variety charger types Continued page 110 December 1990 31 AIR WOLF EPOXY FIBERGLASS FUSELAGE S TAKES MOST 50-60 MECHANICS OTHER MODELS AVAILABLE LARRY JOLLY MODEL PRODUCTS $21000 5501 WCOMO SANTA ANA CALIFORNIA 92703 714 826-6861 Z ty/Preston Continued page 25 Battle Britain No doubt aware 1990 marks 50th anniversary Battle Britain Im sure watched recent Masterpiece Theatre production Piece Cake some outstanding aerial shots WW II aircraft So story wasnt hotso what have just learned coming weekend September 8-9 will Spitfire 109 Manassas Airport close Wash ington DC Unfortunately will get see beauties since American Airlines co operates will cruising aboard 42-ft sail boat Caribbean So now know months column has lot non-safety-related material due before due leave pre cious little time write Labor Day being spent front word processor hope others fortunate out fly ing model pterodactyls I When responding advertisers mention read about ModelAviation Radio Technique/Myers Continued page 31 remember father owned service station dispenser gasoline grease jobs 1930s charger consisted selenium rectifier light bulb rectifier converted AC DC light bulb regulated cur rent put battery battery discharged bulb glowed brightly showed high resistance limiting current went battery battery became fully charged light went Out current battery re duced trickle wondered about time later realized Dads charger ba sically constant-voltage type voltage chosen produce trickle charge charged batteries can still buy Dads charger local Sears store packed up neat steel box handle leads directly CaRa 12-volt automa tic charger standard model de signed charge lead-acid batteries capaci ties six 12 ampere-hour range heavyduty model 2 25 amp available Sail plane winch batteries electric-powered plane mass-charger batteries etc plug either 110 VAC leave connected bat tery whenever latter use will auto matically restore charge hold battery constant state readiness 132 VDC room temperature Both models available pre adjusted hold constant 132 VDC Wet motor cycle batteries extremely variable instruc tions included matching charger whatever ha-ye Either charger can ised properly sized 12-volt read-acid batterywet main tenance-free seled gdled electrolyte types water level wet cells should checked six montss though will notice pulsed charge-Irilding current CaRa dissociates less water battery constant-current trickle charger can testify personal experience gelled cells will last longer charger other types Again have six years experi ence GelCellTe CaRa charger lot got first GelCells constant-current charger have same six years experience motorcycle bat tery CaRa charger Ive keep adding water Ive noticed add less water case constantcurrent charger CaRa automatic 12-volt charger puts Out Continued page 114 BALSA WOOD 6Y1Wi48 TIT T7 W1 1/8 912 BALSA WOOD1/83/161216 STiCKS1/8 1/41418 1/8 3/81722 1/18-INcH364 1/8 1/21828 1/16 1116091/8 3142635 1/I6 07 1/16 1/809 1/16 10 1/161/411 1/18 3/814 1116 1/217 1/183/422 3/16-INcH3848 12 143/163/161418 163/18 1/41620 183/163/81722 213/16 1/22127 303/16 3/43041 3/32-INcH3648 1/4INcH3648 3/323/3209121/4 1/41722 3/32 1/810141/43/81927 3/323/1611181/4 1/22231 3/32 1/414171/4 3/43445 3/323/81020 3/321/21722 3/32 533 * Ocuble BIa W,4 Price Pr Spruce ,d 8a,44d Slick 1/8INCH3648 3/8INcH3648 3/8 rr 3/82940 3/8 1/23344 3/8 784 1/2INcH3848 1/21/24052 1/2 3/45875 TRIANGULAR CUT BALSA 1/4 1/43627 3/83/83631 1/2 1/23640 3/4 3650 113665 BALSA PLANKS 3/4336190 1236179 1336248 5/18INcH38481 Ir 4 36324 _____________ 2236 246 5/165/1623282336302 5/183/825322436498 5/161/230393336524 5/163/442563436728 EN ALSA SHEETS 1-INcH3648 1/16 9 3/32 3 1/8 13547 3/18 2 1/414481 3/8 15777 1/2 17094 2INcH3648 1/32 3 1/1623951 3/32 8 1/8 24984 3/1625877 1/4 28790 3/8282110 1/22121181 3-INcH3648 1/3234357 1/1634882 3/32 0 1/836486 3/16 377102 1/4390120 9/163110143 3/83128171 1/23161214 4INcH3648 1/32 3 1/16478108 3/32488117 1/84102135 3/164122162 1/44140207 3/84195290 1/2 348 1/461277 1/4 12 12198 1/4 1224314 1/4 1248626 3/81212193 3/8 12 24385 3/8 1248770 1/2 12 12218 1/2 1224433 1/2 1248885 1/64 12 12195 1/64 12 24389 1/64 1248801 1/6448483204 1/3261264 1/32 12 12127 1/32 1224257 1/32 1248506 1/1661263 1/16 12 12125 1/16 4250 1/16 12 48509 3/3261297 3/321212194 3/32 12 24387 3/32 1248774 1/8612107 1/8 12 12213 1/8 12 24425 TAPERED TRAILING 1/8 1248850 EDGE36 48 3/186 12791/8 1/22432 3/16 12 121563/16 3/43143 3/16x12243141/4 14288 3/161248626 5/16 11/44785 3/8 11/25877 * OPEN TO THE PUBLIC * Superior Aircraft Materials 12020-G Centralia iian Gardens California 90716 865-3220 Handling Charge -$500 $350 C0D mum Order $2000 plus UPS accept Personal checks COD fornia Residents add 6% Sales Tax LITE PLYWOOD 1/8121282 1/81224184 1/8 1248328 110 Model Aviation TAIBI BIRCH PLYWOOD FROM WEST COAST ENGINES FULLY ADJUSTABLE ENGINE MOUNTS -NO DRILLINGFor 35 80 Size 2 Cycle Engines INTRODUCTORY SPECIAL$1995 Extruded 6061 Aluminum Fits Most Planes Perfect Test Stand Jack Screw Clamping Positive Holding Fits Medium 4-Strokes ENGINE SALE -While LastRossi 90 Front Intake Rossi 91 Rear Intake Webra 80 Ducted Fan Royal 28 ABC Ross Collector $49500 I24 L VISA MASTERCARD DISCOVER 619 951-8349 WEST COAST ENGINES 17080 Bear Valley Rd SteD-3-243 Victorville CA 92392 $13995 $14995 $12995 $6995 continued page 110 pulses charging current measuring battery voltage very precise internal voltmeter tween pulses As battery voltage rises near maximum allowable 132 VDC pulses get shorter off time gets longer producing charge-holding rate just compen sates self-discharge An LED front panel glows steadily just like Dads charger battery contains little charge pulses battery goes charge-holding ad just potentiometer front panzl make light go Out battery fully charged just way Dad did just remembered Dads charger big rheostat could ad justed match fully charged battery voltage adjustment used mainly charge several batteries series Dad kept charger wheeled cart because big heavy clumsy CaRa auto matic 12-volt charger fits hand thanks Ralph Croaning CaRa Gates Battery Manual Both contributed much information column standard rate charger amp six- 12ampere-hour sealed wet batteries costs $4695 plus $3 P&H high-rate charger 2 25 amps winch batteries costs $5895 plus $4 P&H der CaRa Canton SD 57013 Ready 91 /Myers Continued page 43 certainly will lose other users new users will interfere obso lete RC systems keep service Any reasonable person will understand up graded equipment necessary protect investment hobby WHO DOES THE WORK work have send equipment somewhere have serviced have pass word along millions dont belong AMA since wont have opportunity read magazine Let say word favor clubs have open enrollment vite just anybody join club have opportunity exert some control over members have closed membership list have no con trol get blamed transgressions Does really matter made noise lost field flew what pro hibited airspace crashed field gone its gone have outsiders inside club have some control over Theyve got something lose benefit dues paid Two-thirds wont active club anyway according observations club offi cers everywhere main effect membership money club treasury Some money will go newsletter will read fluence will extended main effect having outside club stand have less no effect since may actively resist advice just because ex cluded following firms able test performance transmitters install RCMA/AMA Gold stickers justi fled may also undertake make neces sary alignments surveyed could find kept adding information until magazine deadline Some data probably probably have changed already Beware firms cant install RCMA/AMA sticker phony sticker no sticker can mean no AMA insurance equip ment FCC-legal Ponder LISTED IN ORDER OF RICMA/AMA STICKER NUMBERS Included brief summary ser 114 Model Aviation Airborne Electronic Systems last failsafe battery backup system gives glitch free battery backup allowing continue flying AJI switching fully electronic no relays mechanical switches fail Upon landing once transmitter turned off unit emits loud audible alarm main receiver pack discharged below safe limit system has switched backup mode using optional NiCAD backup packs recharging automatic receiver pack charged Factory Direct $3995 Call free brochure products AES 16055 Caputo Drive Unit D[j[~j an Hill CA 95037 Tel 408 779-4832 K Airborne Watchdog Model AWl -s
Edition: Model Aviation - 1990/12
Page Numbers: 30, 31, 110, 114
George Myers 7adiomchnque ABSTRACT Narrow-band transmitter NPRM dis cussed Lead-acid battery charging Correction October 1990 issue MA ran schematic illustrating boost power servos plugging second battery receiver pix PC board okay callout wasnt Its postive land should cutEd Narrow band 93 long-awaited NPRM FCC Notice Proposed Rule Making regarding narrow-band transmitters RC systems has fi nally published So does affect have greatly simplified language il lustrate changes Type Acceptance criteria prior March 1 1993 Wideband Maximum Sideband Power kP dB Frequency precision % about 3600 Hz Type Acceptance criteria after March 1 1993 Narrow band Maximum Sideband Power -56 kP dB Frequency precision % about Hz can see maximum permitted power interference-producing transmitter sidebands must reduced about 13 dB kP refers additional reduction propor tional power transmitter Since RC transmitters have about same power effect kP reduction will relatively moderate equitable fliers will however re duce sidebands high-powered PRS sta tions between channels 10 kHz away Safer flying conditions coming Frequency tolerance has narrowed 60% need greater precision narrowband environment Incidents traceable offfrequency transmitters should diminish Summary proposed changes 1 Import US manufacture wideband transmitters ends March 1 1992 2 US sales wideband transmitters ends March 1 1993 3 Through March 1 1993 0005% XTALS may sold RC systems 4 After March 1 1993 0002% XTALS will required RC systems 5 Wideband RC transmitters service before March 1 1993 may used afterward grandfather clause lets use old equipment long works Ref NPRM RM-6683 RM-6746 PR Docket 90-20554 Most manufacturers foreign domestic have meeting transmitter requirements since 1988 Thats see Gold stickered transmitters around Everybody knows proposed changes will work transmitters conforming can produced economically NPRM creates safe conditions input 50-channel spectrum Obtaining safe output spectrum other matter Note NPRM says nothing about receivers AMA Guidelines membership manual have quite bit say about receivers order make best use what have given will need narrow-band re ceiver Dual-conversion receivers will reject interference can found RC bands Single-conversion receivers can also de signed resist such interference old wideband AM OWBAM single-conversion re ceivers wont particular OWBAM users must now watch out 21M may created pair transmitters 23 channels apart imaging affects RC channels 11 through 14 57 through 60 Prior January 1 1991 AMA phase-in plan blocked out half 50 chan nels avoid 21M imaging known problem OWBAMs During protected period dual-conversion narrowband FM systems have developed brought market up make use FCC planning force Left Sukhol Su-26 acrobatic airplane hottest machine air show circuit Note visibility cockpit size wheels Right Just like helicopter Sukhoi Su-26 can hang its three-bladed counterclockwise-turning propeller 325-hp radial gives machine better vertical performance Radio Control model have seen Sussex New Jersey Air Show April 26 1990 30 Model Aviation 70 Froeblich Farm Rd Hlcksvllle NY 11801 may look like Saipan 1945 its actually MacArthur Airport islip NY 1990 Fifi last flying 5-29 belongs Confederate Air Force air show fliers CaRa standard chargers use leadacid wet geiled-electrolyte batteries Batter ies last longer use CaRa charger See text order change fact NPRM specifically autho rizes continued use OWBAMs friends want use some type arrangement avoids modeler-to-modeler interference go ahead can use unstickered OWBAM transmitter club field long club will accommo date what happens fly public facility us very likely AMA mem bership will required insurance AMA Safety Code will posted en forced first entry under Safety Code Insur ance 1990 membership manual reads follows Model flying must accordance code order AMA liability protec tion apply think its likely informed public author ity will soon require use narrow-band equipment within parkgrounds can follow line reasoning cant Narrow-band equipment available safer Safer equip ment wont cost Parks Commissioner thing will make flying less likely gener ate lawsuits require Item Three Safety Code states established will abide safety rules flying site use ow have interest ing situation fly public park narrow-band equipment required use OWBAM have accident will violation park rules also will AMA liability protection See works OWBAMs may legal remain ing days few numbered opinion should modify narrow bandor wear out soon Lead-acid batteries Previous columns have dis cussed charging nickel-cadmium batteries month Ill discuss lead-acid cells acid used sulfuric acid very corrosive can tell what kind cell have mea suring voltage fully charged cell shows 22 volts open circuit no-load test cell lead-acid type cell has remov able cover must add distilled water time time make up water dis sociated hydrogen oxygen charg ing process gases explosive lead-acid charging site must well ventilated cell doesnt have removable covers sealed cell may contain gelled electro lyte dont have cant add water sealed cell big advantage sealed leadacid battery wont find corrosion un expected placesor holes garments after washed discharge characteristic lead-acid cell shows shallow slope terminal voltage falling about 8% 80% charge de pleted Voltage flattest part curve affected discharge rate cell dis charged C/l0 10-hour rate voltage will start 22 VDC per cell usable capacity will approximately value marked case eg 12 ampere-hours discharge done C one-hour rate voltage will start about 21 VDC per cell available capacity will about 70% 84 ampere-hours Raising discharge current lOC six-minute rate drops starting volt age 185 VDC per cell available capac ity about 35% 42 ampere-hours rate Thats automobile batteries rated both total capacity cranking amps lost ca pacity isnt really lost want recover must discharge cell lower rate Small lead-acid batteries frequently used start model airplane engines electric starter motors used can easily draw 30 amps working against stiff flooded engine So can see should pick battery large enough job common see lead-acid batteries auto mobiles electric-powered vehicles like golf carts because theyre cheaper nickelcadmium batteries provide same service can kept charged other hand its com mon see nickel-cadmium batteries used air planes freedom necessity charging lack corrosion problems important considerations Ni-Cds per fect model airplanes because arent dam aged neglect way lead-acid batteries Retained capacity strongly affected tem perature freezing point 32 0F 0 0C leadacid charge storage time about year 1400F 600C unreasonable tem perature see inside trunk car charge storage time drops about four days discharge point taken 198 volts per cell open circuit no-load room temper ature should remember number cause cant suck out gelled electrolyte measure its specific gravity can wet lead-acid cells important keep lead-acid batteries charged because letting cell voltage drop low 18 VDC per cell causes permanent cell dam age Overcharging regular rate C/b can permanently damage lead-acid cells Lead-acid cells arent tolerant nickel cadmium cells abuse As nickel-cadmium battery chargers market offers large variety charger types Continued page 110 December 1990 31 AIR WOLF EPOXY FIBERGLASS FUSELAGE S TAKES MOST 50-60 MECHANICS OTHER MODELS AVAILABLE LARRY JOLLY MODEL PRODUCTS $21000 5501 WCOMO SANTA ANA CALIFORNIA 92703 714 826-6861 Z ty/Preston Continued page 25 Battle Britain No doubt aware 1990 marks 50th anniversary Battle Britain Im sure watched recent Masterpiece Theatre production Piece Cake some outstanding aerial shots WW II aircraft So story wasnt hotso what have just learned coming weekend September 8-9 will Spitfire 109 Manassas Airport close Wash ington DC Unfortunately will get see beauties since American Airlines co operates will cruising aboard 42-ft sail boat Caribbean So now know months column has lot non-safety-related material due before due leave pre cious little time write Labor Day being spent front word processor hope others fortunate out fly ing model pterodactyls I When responding advertisers mention read about ModelAviation Radio Technique/Myers Continued page 31 remember father owned service station dispenser gasoline grease jobs 1930s charger consisted selenium rectifier light bulb rectifier converted AC DC light bulb regulated cur rent put battery battery discharged bulb glowed brightly showed high resistance limiting current went battery battery became fully charged light went Out current battery re duced trickle wondered about time later realized Dads charger ba sically constant-voltage type voltage chosen produce trickle charge charged batteries can still buy Dads charger local Sears store packed up neat steel box handle leads directly CaRa 12-volt automa tic charger standard model de signed charge lead-acid batteries capaci ties six 12 ampere-hour range heavyduty model 2 25 amp available Sail plane winch batteries electric-powered plane mass-charger batteries etc plug either 110 VAC leave connected bat tery whenever latter use will auto matically restore charge hold battery constant state readiness 132 VDC room temperature Both models available pre adjusted hold constant 132 VDC Wet motor cycle batteries extremely variable instruc tions included matching charger whatever ha-ye Either charger can ised properly sized 12-volt read-acid batterywet main tenance-free seled gdled electrolyte types water level wet cells should checked six montss though will notice pulsed charge-Irilding current CaRa dissociates less water battery constant-current trickle charger can testify personal experience gelled cells will last longer charger other types Again have six years experi ence GelCellTe CaRa charger lot got first GelCells constant-current charger have same six years experience motorcycle bat tery CaRa charger Ive keep adding water Ive noticed add less water case constantcurrent charger CaRa automatic 12-volt charger puts Out Continued page 114 BALSA WOOD 6Y1Wi48 TIT T7 W1 1/8 912 BALSA WOOD1/83/161216 STiCKS1/8 1/41418 1/8 3/81722 1/18-INcH364 1/8 1/21828 1/16 1116091/8 3142635 1/I6 07 1/16 1/809 1/16 10 1/161/411 1/18 3/814 1116 1/217 1/183/422 3/16-INcH3848 12 143/163/161418 163/18 1/41620 183/163/81722 213/16 1/22127 303/16 3/43041 3/32-INcH3648 1/4INcH3648 3/323/3209121/4 1/41722 3/32 1/810141/43/81927 3/323/1611181/4 1/22231 3/32 1/414171/4 3/43445 3/323/81020 3/321/21722 3/32 533 * Ocuble BIa W,4 Price Pr Spruce ,d 8a,44d Slick 1/8INCH3648 3/8INcH3648 3/8 rr 3/82940 3/8 1/23344 3/8 784 1/2INcH3848 1/21/24052 1/2 3/45875 TRIANGULAR CUT BALSA 1/4 1/43627 3/83/83631 1/2 1/23640 3/4 3650 113665 BALSA PLANKS 3/4336190 1236179 1336248 5/18INcH38481 Ir 4 36324 _____________ 2236 246 5/165/1623282336302 5/183/825322436498 5/161/230393336524 5/163/442563436728 EN ALSA SHEETS 1-INcH3648 1/16 9 3/32 3 1/8 13547 3/18 2 1/414481 3/8 15777 1/2 17094 2INcH3648 1/32 3 1/1623951 3/32 8 1/8 24984 3/1625877 1/4 28790 3/8282110 1/22121181 3-INcH3648 1/3234357 1/1634882 3/32 0 1/836486 3/16 377102 1/4390120 9/163110143 3/83128171 1/23161214 4INcH3648 1/32 3 1/16478108 3/32488117 1/84102135 3/164122162 1/44140207 3/84195290 1/2 348 1/461277 1/4 12 12198 1/4 1224314 1/4 1248626 3/81212193 3/8 12 24385 3/8 1248770 1/2 12 12218 1/2 1224433 1/2 1248885 1/64 12 12195 1/64 12 24389 1/64 1248801 1/6448483204 1/3261264 1/32 12 12127 1/32 1224257 1/32 1248506 1/1661263 1/16 12 12125 1/16 4250 1/16 12 48509 3/3261297 3/321212194 3/32 12 24387 3/32 1248774 1/8612107 1/8 12 12213 1/8 12 24425 TAPERED TRAILING 1/8 1248850 EDGE36 48 3/186 12791/8 1/22432 3/16 12 121563/16 3/43143 3/16x12243141/4 14288 3/161248626 5/16 11/44785 3/8 11/25877 * OPEN TO THE PUBLIC * Superior Aircraft Materials 12020-G Centralia iian Gardens California 90716 865-3220 Handling Charge -$500 $350 C0D mum Order $2000 plus UPS accept Personal checks COD fornia Residents add 6% Sales Tax LITE PLYWOOD 1/8121282 1/81224184 1/8 1248328 110 Model Aviation TAIBI BIRCH PLYWOOD FROM WEST COAST ENGINES FULLY ADJUSTABLE ENGINE MOUNTS -NO DRILLINGFor 35 80 Size 2 Cycle Engines INTRODUCTORY SPECIAL$1995 Extruded 6061 Aluminum Fits Most Planes Perfect Test Stand Jack Screw Clamping Positive Holding Fits Medium 4-Strokes ENGINE SALE -While LastRossi 90 Front Intake Rossi 91 Rear Intake Webra 80 Ducted Fan Royal 28 ABC Ross Collector $49500 I24 L VISA MASTERCARD DISCOVER 619 951-8349 WEST COAST ENGINES 17080 Bear Valley Rd SteD-3-243 Victorville CA 92392 $13995 $14995 $12995 $6995 continued page 110 pulses charging current measuring battery voltage very precise internal voltmeter tween pulses As battery voltage rises near maximum allowable 132 VDC pulses get shorter off time gets longer producing charge-holding rate just compen sates self-discharge An LED front panel glows steadily just like Dads charger battery contains little charge pulses battery goes charge-holding ad just potentiometer front panzl make light go Out battery fully charged just way Dad did just remembered Dads charger big rheostat could ad justed match fully charged battery voltage adjustment used mainly charge several batteries series Dad kept charger wheeled cart because big heavy clumsy CaRa auto matic 12-volt charger fits hand thanks Ralph Croaning CaRa Gates Battery Manual Both contributed much information column standard rate charger amp six- 12ampere-hour sealed wet batteries costs $4695 plus $3 P&H high-rate charger 2 25 amps winch batteries costs $5895 plus $4 P&H der CaRa Canton SD 57013 Ready 91 /Myers Continued page 43 certainly will lose other users new users will interfere obso lete RC systems keep service Any reasonable person will understand up graded equipment necessary protect investment hobby WHO DOES THE WORK work have send equipment somewhere have serviced have pass word along millions dont belong AMA since wont have opportunity read magazine Let say word favor clubs have open enrollment vite just anybody join club have opportunity exert some control over members have closed membership list have no con trol get blamed transgressions Does really matter made noise lost field flew what pro hibited airspace crashed field gone its gone have outsiders inside club have some control over Theyve got something lose benefit dues paid Two-thirds wont active club anyway according observations club offi cers everywhere main effect membership money club treasury Some money will go newsletter will read fluence will extended main effect having outside club stand have less no effect since may actively resist advice just because ex cluded following firms able test performance transmitters install RCMA/AMA Gold stickers justi fled may also undertake make neces sary alignments surveyed could find kept adding information until magazine deadline Some data probably probably have changed already Beware firms cant install RCMA/AMA sticker phony sticker no sticker can mean no AMA insurance equip ment FCC-legal Ponder LISTED IN ORDER OF RICMA/AMA STICKER NUMBERS Included brief summary ser 114 Model Aviation Airborne Electronic Systems last failsafe battery backup system gives glitch free battery backup allowing continue flying AJI switching fully electronic no relays mechanical switches fail Upon landing once transmitter turned off unit emits loud audible alarm main receiver pack discharged below safe limit system has switched backup mode using optional NiCAD backup packs recharging automatic receiver pack charged Factory Direct $3995 Call free brochure products AES 16055 Caputo Drive Unit D[j[~j an Hill CA 95037 Tel 408 779-4832 K Airborne Watchdog Model AWl -s