George Myers Radio Thchnique 70 Frodilkh Farm Rd Hkksville NY 11801 ABSTRACT Predicted 1991 operating condi tions whether AMA goes 50 channels Part 1 Single-conversion receivers WHATS AHEAD recently received letter Dear George just recently joined AMA am now wor tying about 1991 specifications radio Will able use 1988 name deleted AM radio equipment matter other non 1991 equipment after 1991 Will manufacturers continue offer cheaper line radios like four channels $100 am very confused s/Jim Hobelsberger 2956 Kelly Rd La Cres cent MN 55947 answer him follows Dear Jim First important 1988 system has narrow-band transmitter Tx pretty good receiver Rx will work through 1991 beyond people confusing probably have older equipment isnt good yours Now lets look situation folks old equipment am lawyer legal advice way understand situation Equipment manufactured Type Acceptance certificate issued manufacturer FCC can legally used RC flying long 50 Aircraft Only 72 MHz chan nels six models 27 MHz channels ap proved RC use FCC have Amateur Radio Operators license can fly ten 50 MHz eight 53 MHz channels Thats 74 channels available have right fly Type Accepted equipment until either wears out dispose So can fly what have 1991 beyond difficulty Type Acceptances dont have expiration dates FCC reg ulations change production obsoleted equip ment ceases owner equip ment have no way knowing about know transmitter holding has Type Acceptance sticker Therefore some thing built 1970 under Type Acceptance Type Certification force THEN before cur rent narrow-band channels existed legally us able NOW can see danger cant has talk about asking FCC put time limit legal use obsolete equip ment nothing has come sticking point definition obsolete AMAs program put Gold Silver stickers transmitters has conducted filter out dangerously inadequatebut other wise legalequipment still around credit modelers everywhere under stood what being done reacted respon sibly AMA Radio Guidelines published Membership Manual describe per formance characteristics radios should able work together 50-channel 1991 en vironment might guess anything doesnt conform guidelines obsolete sense could true have re member guidelines FCC regula tions Therefore cant obsolete anything As written 1988 Membership Manual page 11 guidelines little vague about single-conversion receivers will cor rected can ignore guidelines until want fly AMA-sanctioned competition case will need narrow-band transmitter defined AMA Radio Guidelines en ter competition channels RC12 14 16 34 right now Wide-band transmitters accept able channels RC38 40 42 right now Beginning 1991 youll need narrow-band transmitters Gold stickers whatever other documentation AMA requires fly competition channel no distinc tion between AM FMor between PCM other encoding schemesin guidelines FM isnt way go AMA does require narrow-band RE CEIVER competition use time opinion should Until narrow-band receiv ers required AMA Contest Directors must counted schedule use RC channels competition events way minimizes modeler-to-modeler interference taking ac count characteristics receivers currently use None manufacturers representatives 36 Model Aviation Too bad isnt color Larry Bashores Mechanicsburg PA Great Lakes 2T biplane gleams redlwhitelblue paint might prototype Georges next Scale ship plane uses flat-4 Lycoming AEI0-360 engine instead original inverted inline Menasco engine Myers has seen entered Aerobatics competition Jaffrey NH Red Lion NJ Polks Powermax Merlin PCM single-conversion narrow-band receiver free inter ferences will introduced 50 aircraft-only RC channels opened up 1991 PCM computer vital type performance since can reconstruct valid control information previously received signals thereby continuing maintain control face 50% Interferencel Myers has say about radio month Ive spoken reports plan continue pro ducing what used sell stopped producing what would call low-performance equipment five years ago has steady improvement performance equipment offered sale point some cheapest radios 1988 outperform highest priced radios 1982 earlier dont meet AMA guidelines Expect see high-performance narrow-band four- six-channel channel FM setsand/or five-channel FM/PCM setsas everybodys low-cost model immediate future Since practically RC equipment comes Far East price will function US dollars value relative Far East currencies anticipated future price leaders will cost less $200 know AMA plans sanction use 50 aircraft channels 1991 also know some 40 kHz forever sentiment intended prolong use old wideband equipment Let get out crystal ball see what changes operating conditions will result depending plan followed First AMA sanctions even-numbered channels 40 kHz forever FCC al certain assign odd-numbered channels someone else critical point remember 50 channels exclusive us now BUT WE ARE ONLY ACCORDED THE STATUS OF SECONDARY USERS means must accept interferencebut cant give anyif let some other service capture odd channels think cant happen Amateurs have just lost 2 MHz 220 MHz band because FCC believed werent using now accept concept SOME BODY will using 50 channels 1991 first thing consider logically follows fact mathematics radio fre quencies Most single-conversion SC super heterodyne receivers use 455 kHz local oscilla tor LO frequency lets call SC455s Under very specific circumstances following wideband SC455s may see increase interfer ence 50 channels used some body Most old wideband AM OWBAM radios SC455s Direct Interference 1 The 5C455s local oscillator LO frequency almost coincides RC transmitter Tx 23 channels away also almost coincides Common Carrier Tx guys tween RC channels located 22 channels Hz away Whether cause interfer ence depends upon position band interfer ing Tx above below receiver Rx proper ties way avoid bad effects situation build SC455s RC 11-35 LO frequency below Tx frequency SC455s RC36-60 LO above Tx frequencyso long interfere suffer interference other services out side RC band AMA guidelines say opposite written around dual-conversion receivers have no 23-channel problem large number re ceivers exist have LO placed inside RC band accordance guidelines AMA Phase-In Plan masked 23-channel consideration sanctioning use odd-numbered RC channels LO placed correctly SC455s RCll 12 59 60 can interfered Tx Continued page 141 DISCOVER HOW EAS CAN BE 1nfroduczp1 XT-1 Transmitter Tray N BJ ENTERPRISES 1100 Center Street Bsvre Montana 59501 Experience Thrill Toy. XT-1 Transmitter Tray wIth set Gimbal Extenders $350 Postage & Handling TO ORDER CALL 14062654828 Make Flying Breeze April 1989 37 Invisible SvitchTM direct replacement radio on/off switch Und Ye Call Der Svitch Der Svitch on-board magnetic on/off switch radio equipment hides inside fuseiage activated outside included small bar magnet slown above cut awful hoies fuselage. isnt time made Der Syitch Ideal Any RIO Plane Boat Car e Prolects r Flyers Safe use Consumes no power ation free h resistant atible radio Optional red LED lamp installs plane dash wing indicate radio state Simple Install Futaba Airtronics radios order Model 1402 simply unplug on/ott switch plug Der Svitch order Model 1401 use connectors trom old on/off switch instructions supplied Der Syitch includes bar magnet activator shown above ModelDescriptionPrice ea 1401Der Svttch activator no connectors twisted Ieadn$1995 sa l4O1LEDDerSvitch activator no connectors twisted leads option eads tor external LED #1405$2495 ea 1402*Der Svttcb activator connectors br Futaba Airtronics$2495 sa 14O2LED*Der Svitch activstor connectorn tor Futaba Airtronics option leads tor external LED #1405*$2995 sa 1405LED red lamp w/24 twisted leads tor Models 1401 LED 1402LE0$895 sa * ordering Model 1402 14O2LED please specify radio connectortypes Connectors available tor Futaba J Futaba G Airtronics radios order include name address specity models needed include check money order send Ragan/Barker Group 5050 Quorum Drive Suite 741 Dallas Texas 75240 Please add $250 per order cover UPS charges Texas residents add sales tax Credit Card orders call between 900 500 Central Time M-F Please allow 2-4 weeks delivery Patent Pending Dealer Inquiries Invited 4 Introductory Offer. 41 II 41 1t I] iyu 111 E1ii RE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SHEETS 36 48 30 BALSA STICKS 3648 16233 332240 18243 316249 14256 132337 20337 163374931 33234458 37 1835471 45 31636282 55 14373 95 61 516395110 38355124 71 123110155 34 3165191 116455 7648 332470 9456 18 48010666 316493122 75 14411013484 38 4165225139 12 4225261 MATCHED SHEETS 42 3324100 164109 3164120 144131 116 14 116 36 116 12 332 14 332 35 332 12 18 18 18 14 18 36 18 12 316316 316 38 316 12 14 14 14 30 412 14 34 141 516516 3838 3812 3634 381 1212 1234 121 58 55 34 34 Os 10 14 10 12 16 08 11 12 18 11 17 22 16 19 21 34 40 21 27 32 42 52 36 46 56 48 67 16 18 24 16 20 30 24 26 30 44 55 28 37 46 55 70 53 62 78 66 90 BALSA HOT LINE Call 806 745 6394 10am 6pm Central Time BALSA TRIANOL ES 36 25 8830 35 45 55 BALSA PLANKS36 86 0 00 1480 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS36 142 65 143 65 382 83 23120 LONE STAREPOXY 90L sI--S 95 5so598 iSoro598 38 rro598 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 1 32 3 1/203 1163 332 3 183 3 163 143 383 123 343 13 1 164 3 324 184 3164 144 384 124 36 53 53 53 63 77 89 104 122 158 242 335 83 100 115 133 158 236 322 TRAILING EDGE 36 14132 51611439 3811246 12270 INSTANTOLUE 1 o TSck 298 10 750 298 20 T5ck 550 20 150 550 BASSWOOD 316316 31614 31638 31612 31634 1414 1438 1434 3838 3/812 3634 12 1 2 1234 BUNDLE DEALS 28116336695 201164361035 20332 336865 15332 436955 151/8336738 101/8436895 15318336920 10316436835 1014336655 101/4436830 103/8336870 53/84 36655 51/2336540 5124361580 10-3324 48885 518448500 5316 4 48600 514448645 48*NEW* 26Hundreds 30 38 46 cessories 60 ishing 42 materials 80 60 #10 SASE 70 atest 90 catalog 100SPRUCE STICKS 3648 18 181725 18 142026 18 3/822 32 316316 28 38 14 3/84055 14 124585 3/8 3/84969 38 126577 12 I/O6688 12347597 SPRUCE TRIANGLES 38 38 12 1 2 34 34 1846 18412 146 HARD MAPLE 1 4 36 3838 38 12 3834 1 2 IRCH DOWELS 18 316 14 516 38 18 40 45 50 58 68 36 09 11 14 25 32 3PiVBIRCH48 16412620 13212445 11612455 1812485 SPLVBIRCH 48 33212588 1/812 625 36316 12625 4714 12828 8438 12725 8112 12900 LITE PLY 48GROOVED LGMOUNTS lllachea 15538341840 3153834/532140 2501234916/45 495 V. Push-Pull/Masters Continued page 137 prop author owned full-scale Lake Amphibian pusher years found protecting propeller loose nuts bolts fishing rods always major concern twin engine push-pull arrangement especially vulner able front prop can kick up stones starter cables wiping cloths etc promptly present rear prop digestion Flying twin pusher also requires special watchfulness flight Push-Pull 240 near-fiasco Immediately after takeoff carburetor aft engine came loose moved pusher prop promptly seif-destructed en gine full bore extremely unbalanced tore itself firewallbefore fuel starvation saved day whole scenario lasted about three four seconds pilot Ray Doan brought ship back single engine thorough preflight check would have spared pusher prop main thing remember get Push-Pull smoothly aloft advance throttles steadily during takeoff Ground control will positive no torque cor rection required Clinibout will solid watch slice through ether sound twin 40s something else Radio Technique/Myers Continued page 37 RC34 through RC37 vice versa 2 next condition change comes out mathematics frequencies coo Image interfer ence will return few SC455s Some folks will remember 7296 Y/W used image 7208 Bn/W Well SC455s RCll-14 RC57-60 can af fected Tx within band have local oscillator wrong side assume manufacturers simply wont sell SC455s channels Besides image coincides exactly Common Car rier Tx frequencies RC Tx helps Rx low LO have possibility imaging TV4 RC44 problem know love So see nothing simple cure above simple Use dual conversion Rx entry-level RC system almost always uses SC455 manufacturers will have narrow-band pay attention proper LO signments keep off RCll 12 13 14 34 35 36 37 57 58 59 60 Jim didnt mention channel doubt above manufacturers just arent selling Indirect Interference condition comes out numbers called Second Order Intermodulation Product Interfer ence 21M generated ANY PAIR Tx operating 23 RC channel numbers apart difference two frequencies modu lated 460 kHz signal often goes right through 5C455 detected interference Think 21M generated JUST ONE PAIR Tx might hit OWBAM SC45Ss SO channels simultaneously including own Rx depending signal strength Rx tenna RECEIVER CHARACTERIS TICS Nobody uses odd-numbered RC chan nels RCll 13 15 today dont see 21M Can predict what will happen give 25 odd-numbered channels another service Now remember discussing RE CEIVER problems assumption everyone already using Gold-stickered narrowband transmitters Practically Tx built since 1987 good enough warrant sticker easiest way avoid problems listed above use dual-conversion receiver dont have block out ANY channels Jim manufacturer offers best dual-conversion receivers market relatively cheap recommend letter appropriate person named end last months column narrow-band 5C455 can work cause interferences discussed above z off 455 kHz intermediate frequency IF dead like 31M Narrow-band SC455s exist example Bob Aberle recently tested Polks Pow ermax Merlin system receiver 5C455 RC46 its LO low side An IF bandwidth 6 dB 2 kllz claimed nothing quoted 85 kHz Merlin performance meets AMA guide lines except ins LO wrong side does use dual conversion DC outper formed 1991 DC system have tested ex cept its PCM computer slow April 1989 141 LONE STAR MODELS1412 1623 S7th St Lubbock TX 79412 cant 46 Handling charge pay UPS Add $250 COD $300 extra PP APO FPO StateS accept Vs4 Master Card personal checks COO 6% 368/n TenaS US crrency Mnmom Wood Order 51000 I WANNA RACE NORTHEAST AREA A 5- BEGINNER RACES 0-500 * FORM-i * FAI Instructions Club Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVEFRANKLIN MASS 02038 Tel 617 528-4043 203 673-2000 control transmitter 200 ft away can lay RC44 RC48 transmitter antenna right re ceiver antenna driving Merlin PCM system fail-safe Under same conditions can bring RC23 45 47 transmitter within 12 ft receiver before causing fail safe think clearly demonstrates narrow-band SC455 can made work well direct interference transmitter 23 channels away no worse indirect interference Tx channel away youve got nothing worry about AMA has protected OWBAMs long time its carefully selected even-numbered channelshut protection never absolute Now enlightened self-interest forces AMA move better things Prediction #1 Wideband SC4SS receivers will much use 72 MHz Aircraft Only band after 1991 will generally use ful 75 MHz Non-Aircraft Only band either 30 channels used Narrow-band SC455s will work right chan nels however keep telling THE KEY TO THE FU TURE IS GOOD RECEIVER test re sults quoted next section will demonstrate manufacturers have responded challenge good receivers now avail able additional study see AMA Phase-In Plan Explained April 1984 edition AMA News pages 103-104 Continued next month Mods/Berman Continued page 41 swivel-neck because couldnt see straight over tail-draggers nose models fa vor such gear arrangement flying grass fields because tail-draggers rear apex triangle seems provide better ground handling stability nose wheel setup Hence Gerry Terry Grahams Akrobat H tail-dragger sort -scale Laser 200 tempted another desirable building proj ect Examining tail wheel arrangement Akrobat II plans though soon wriniding nose yes feeling unmistakable stirrings urge mod probability Grahams original tail wheel functions perfectly well designed revisions II must confess did wasnt good company Didnt such illustrious aircraft British Comet Lockheed Electra others have design flaws over come degrees rate Akrobat tail wheel Mark III emerged successfully design works leads useful life today sembly shown photo well beyond its 100th contact earth Steering remarkably effective manufactured unit out 040 dural aluminum mooched local fixed base operator Please note shaded area sketch cut away after bending U rather before coping saw fine teeth will job competently Probably qualifying drastic mod forced upon original Hots first seen July 1986 issue Model Airplane News overall de sign very much appealed still lot quibbles An almost 5-ft-wingspan model one-piece structure An inacces sible fuel tank Two aileron servos such relatively small plane aile rons conveniently abut fuselage didnt bother send fullsize plansjust wound up old cerebral escapement struck pencil sheet paper modification evolved seemed satisfy previous objections Rather jamming fuselage servos bottom wing Mark IH would have very slightly fatter belly af fording comfortable mounting space wing would bolt above have single servo actuating both ailerons through torque rods removable top hatch would allow wing demounting also clear space fuel tank removal should become necessary Since unable buy shaped solid aileron stock suitable dimension con structed built-up ailerons 42 balsa little triangular ribs finished prod uct turned out unbelievably rigid worked out splendidly old fat wings will soon celebrate its second birth142 Model Aviation
Edition: Model Aviation - 1989/04
Page Numbers: 36, 37, 141, 142
George Myers Radio Thchnique 70 Frodilkh Farm Rd Hkksville NY 11801 ABSTRACT Predicted 1991 operating condi tions whether AMA goes 50 channels Part 1 Single-conversion receivers WHATS AHEAD recently received letter Dear George just recently joined AMA am now wor tying about 1991 specifications radio Will able use 1988 name deleted AM radio equipment matter other non 1991 equipment after 1991 Will manufacturers continue offer cheaper line radios like four channels $100 am very confused s/Jim Hobelsberger 2956 Kelly Rd La Cres cent MN 55947 answer him follows Dear Jim First important 1988 system has narrow-band transmitter Tx pretty good receiver Rx will work through 1991 beyond people confusing probably have older equipment isnt good yours Now lets look situation folks old equipment am lawyer legal advice way understand situation Equipment manufactured Type Acceptance certificate issued manufacturer FCC can legally used RC flying long 50 Aircraft Only 72 MHz chan nels six models 27 MHz channels ap proved RC use FCC have Amateur Radio Operators license can fly ten 50 MHz eight 53 MHz channels Thats 74 channels available have right fly Type Accepted equipment until either wears out dispose So can fly what have 1991 beyond difficulty Type Acceptances dont have expiration dates FCC reg ulations change production obsoleted equip ment ceases owner equip ment have no way knowing about know transmitter holding has Type Acceptance sticker Therefore some thing built 1970 under Type Acceptance Type Certification force THEN before cur rent narrow-band channels existed legally us able NOW can see danger cant has talk about asking FCC put time limit legal use obsolete equip ment nothing has come sticking point definition obsolete AMAs program put Gold Silver stickers transmitters has conducted filter out dangerously inadequatebut other wise legalequipment still around credit modelers everywhere under stood what being done reacted respon sibly AMA Radio Guidelines published Membership Manual describe per formance characteristics radios should able work together 50-channel 1991 en vironment might guess anything doesnt conform guidelines obsolete sense could true have re member guidelines FCC regula tions Therefore cant obsolete anything As written 1988 Membership Manual page 11 guidelines little vague about single-conversion receivers will cor rected can ignore guidelines until want fly AMA-sanctioned competition case will need narrow-band transmitter defined AMA Radio Guidelines en ter competition channels RC12 14 16 34 right now Wide-band transmitters accept able channels RC38 40 42 right now Beginning 1991 youll need narrow-band transmitters Gold stickers whatever other documentation AMA requires fly competition channel no distinc tion between AM FMor between PCM other encoding schemesin guidelines FM isnt way go AMA does require narrow-band RE CEIVER competition use time opinion should Until narrow-band receiv ers required AMA Contest Directors must counted schedule use RC channels competition events way minimizes modeler-to-modeler interference taking ac count characteristics receivers currently use None manufacturers representatives 36 Model Aviation Too bad isnt color Larry Bashores Mechanicsburg PA Great Lakes 2T biplane gleams redlwhitelblue paint might prototype Georges next Scale ship plane uses flat-4 Lycoming AEI0-360 engine instead original inverted inline Menasco engine Myers has seen entered Aerobatics competition Jaffrey NH Red Lion NJ Polks Powermax Merlin PCM single-conversion narrow-band receiver free inter ferences will introduced 50 aircraft-only RC channels opened up 1991 PCM computer vital type performance since can reconstruct valid control information previously received signals thereby continuing maintain control face 50% Interferencel Myers has say about radio month Ive spoken reports plan continue pro ducing what used sell stopped producing what would call low-performance equipment five years ago has steady improvement performance equipment offered sale point some cheapest radios 1988 outperform highest priced radios 1982 earlier dont meet AMA guidelines Expect see high-performance narrow-band four- six-channel channel FM setsand/or five-channel FM/PCM setsas everybodys low-cost model immediate future Since practically RC equipment comes Far East price will function US dollars value relative Far East currencies anticipated future price leaders will cost less $200 know AMA plans sanction use 50 aircraft channels 1991 also know some 40 kHz forever sentiment intended prolong use old wideband equipment Let get out crystal ball see what changes operating conditions will result depending plan followed First AMA sanctions even-numbered channels 40 kHz forever FCC al certain assign odd-numbered channels someone else critical point remember 50 channels exclusive us now BUT WE ARE ONLY ACCORDED THE STATUS OF SECONDARY USERS means must accept interferencebut cant give anyif let some other service capture odd channels think cant happen Amateurs have just lost 2 MHz 220 MHz band because FCC believed werent using now accept concept SOME BODY will using 50 channels 1991 first thing consider logically follows fact mathematics radio fre quencies Most single-conversion SC super heterodyne receivers use 455 kHz local oscilla tor LO frequency lets call SC455s Under very specific circumstances following wideband SC455s may see increase interfer ence 50 channels used some body Most old wideband AM OWBAM radios SC455s Direct Interference 1 The 5C455s local oscillator LO frequency almost coincides RC transmitter Tx 23 channels away also almost coincides Common Carrier Tx guys tween RC channels located 22 channels Hz away Whether cause interfer ence depends upon position band interfer ing Tx above below receiver Rx proper ties way avoid bad effects situation build SC455s RC 11-35 LO frequency below Tx frequency SC455s RC36-60 LO above Tx frequencyso long interfere suffer interference other services out side RC band AMA guidelines say opposite written around dual-conversion receivers have no 23-channel problem large number re ceivers exist have LO placed inside RC band accordance guidelines AMA Phase-In Plan masked 23-channel consideration sanctioning use odd-numbered RC channels LO placed correctly SC455s RCll 12 59 60 can interfered Tx Continued page 141 DISCOVER HOW EAS CAN BE 1nfroduczp1 XT-1 Transmitter Tray N BJ ENTERPRISES 1100 Center Street Bsvre Montana 59501 Experience Thrill Toy. XT-1 Transmitter Tray wIth set Gimbal Extenders $350 Postage & Handling TO ORDER CALL 14062654828 Make Flying Breeze April 1989 37 Invisible SvitchTM direct replacement radio on/off switch Und Ye Call Der Svitch Der Svitch on-board magnetic on/off switch radio equipment hides inside fuseiage activated outside included small bar magnet slown above cut awful hoies fuselage. isnt time made Der Syitch Ideal Any RIO Plane Boat Car e Prolects r Flyers Safe use Consumes no power ation free h resistant atible radio Optional red LED lamp installs plane dash wing indicate radio state Simple Install Futaba Airtronics radios order Model 1402 simply unplug on/ott switch plug Der Svitch order Model 1401 use connectors trom old on/off switch instructions supplied Der Syitch includes bar magnet activator shown above ModelDescriptionPrice ea 1401Der Svttch activator no connectors twisted Ieadn$1995 sa l4O1LEDDerSvitch activator no connectors twisted leads option eads tor external LED #1405$2495 ea 1402*Der Svttcb activator connectors br Futaba Airtronics$2495 sa 14O2LED*Der Svitch activstor connectorn tor Futaba Airtronics option leads tor external LED #1405*$2995 sa 1405LED red lamp w/24 twisted leads tor Models 1401 LED 1402LE0$895 sa * ordering Model 1402 14O2LED please specify radio connectortypes Connectors available tor Futaba J Futaba G Airtronics radios order include name address specity models needed include check money order send Ragan/Barker Group 5050 Quorum Drive Suite 741 Dallas Texas 75240 Please add $250 per order cover UPS charges Texas residents add sales tax Credit Card orders call between 900 500 Central Time M-F Please allow 2-4 weeks delivery Patent Pending Dealer Inquiries Invited 4 Introductory Offer. 41 II 41 1t I] iyu 111 E1ii RE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SHEETS 36 48 30 BALSA STICKS 3648 16233 332240 18243 316249 14256 132337 20337 163374931 33234458 37 1835471 45 31636282 55 14373 95 61 516395110 38355124 71 123110155 34 3165191 116455 7648 332470 9456 18 48010666 316493122 75 14411013484 38 4165225139 12 4225261 MATCHED SHEETS 42 3324100 164109 3164120 144131 116 14 116 36 116 12 332 14 332 35 332 12 18 18 18 14 18 36 18 12 316316 316 38 316 12 14 14 14 30 412 14 34 141 516516 3838 3812 3634 381 1212 1234 121 58 55 34 34 Os 10 14 10 12 16 08 11 12 18 11 17 22 16 19 21 34 40 21 27 32 42 52 36 46 56 48 67 16 18 24 16 20 30 24 26 30 44 55 28 37 46 55 70 53 62 78 66 90 BALSA HOT LINE Call 806 745 6394 10am 6pm Central Time BALSA TRIANOL ES 36 25 8830 35 45 55 BALSA PLANKS36 86 0 00 1480 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS36 142 65 143 65 382 83 23120 LONE STAREPOXY 90L sI--S 95 5so598 iSoro598 38 rro598 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 1 32 3 1/203 1163 332 3 183 3 163 143 383 123 343 13 1 164 3 324 184 3164 144 384 124 36 53 53 53 63 77 89 104 122 158 242 335 83 100 115 133 158 236 322 TRAILING EDGE 36 14132 51611439 3811246 12270 INSTANTOLUE 1 o TSck 298 10 750 298 20 T5ck 550 20 150 550 BASSWOOD 316316 31614 31638 31612 31634 1414 1438 1434 3838 3/812 3634 12 1 2 1234 BUNDLE DEALS 28116336695 201164361035 20332 336865 15332 436955 151/8336738 101/8436895 15318336920 10316436835 1014336655 101/4436830 103/8336870 53/84 36655 51/2336540 5124361580 10-3324 48885 518448500 5316 4 48600 514448645 48*NEW* 26Hundreds 30 38 46 cessories 60 ishing 42 materials 80 60 #10 SASE 70 atest 90 catalog 100SPRUCE STICKS 3648 18 181725 18 142026 18 3/822 32 316316 28 38 14 3/84055 14 124585 3/8 3/84969 38 126577 12 I/O6688 12347597 SPRUCE TRIANGLES 38 38 12 1 2 34 34 1846 18412 146 HARD MAPLE 1 4 36 3838 38 12 3834 1 2 IRCH DOWELS 18 316 14 516 38 18 40 45 50 58 68 36 09 11 14 25 32 3PiVBIRCH48 16412620 13212445 11612455 1812485 SPLVBIRCH 48 33212588 1/812 625 36316 12625 4714 12828 8438 12725 8112 12900 LITE PLY 48GROOVED LGMOUNTS lllachea 15538341840 3153834/532140 2501234916/45 495 V. Push-Pull/Masters Continued page 137 prop author owned full-scale Lake Amphibian pusher years found protecting propeller loose nuts bolts fishing rods always major concern twin engine push-pull arrangement especially vulner able front prop can kick up stones starter cables wiping cloths etc promptly present rear prop digestion Flying twin pusher also requires special watchfulness flight Push-Pull 240 near-fiasco Immediately after takeoff carburetor aft engine came loose moved pusher prop promptly seif-destructed en gine full bore extremely unbalanced tore itself firewallbefore fuel starvation saved day whole scenario lasted about three four seconds pilot Ray Doan brought ship back single engine thorough preflight check would have spared pusher prop main thing remember get Push-Pull smoothly aloft advance throttles steadily during takeoff Ground control will positive no torque cor rection required Clinibout will solid watch slice through ether sound twin 40s something else Radio Technique/Myers Continued page 37 RC34 through RC37 vice versa 2 next condition change comes out mathematics frequencies coo Image interfer ence will return few SC455s Some folks will remember 7296 Y/W used image 7208 Bn/W Well SC455s RCll-14 RC57-60 can af fected Tx within band have local oscillator wrong side assume manufacturers simply wont sell SC455s channels Besides image coincides exactly Common Car rier Tx frequencies RC Tx helps Rx low LO have possibility imaging TV4 RC44 problem know love So see nothing simple cure above simple Use dual conversion Rx entry-level RC system almost always uses SC455 manufacturers will have narrow-band pay attention proper LO signments keep off RCll 12 13 14 34 35 36 37 57 58 59 60 Jim didnt mention channel doubt above manufacturers just arent selling Indirect Interference condition comes out numbers called Second Order Intermodulation Product Interfer ence 21M generated ANY PAIR Tx operating 23 RC channel numbers apart difference two frequencies modu lated 460 kHz signal often goes right through 5C455 detected interference Think 21M generated JUST ONE PAIR Tx might hit OWBAM SC45Ss SO channels simultaneously including own Rx depending signal strength Rx tenna RECEIVER CHARACTERIS TICS Nobody uses odd-numbered RC chan nels RCll 13 15 today dont see 21M Can predict what will happen give 25 odd-numbered channels another service Now remember discussing RE CEIVER problems assumption everyone already using Gold-stickered narrowband transmitters Practically Tx built since 1987 good enough warrant sticker easiest way avoid problems listed above use dual-conversion receiver dont have block out ANY channels Jim manufacturer offers best dual-conversion receivers market relatively cheap recommend letter appropriate person named end last months column narrow-band 5C455 can work cause interferences discussed above z off 455 kHz intermediate frequency IF dead like 31M Narrow-band SC455s exist example Bob Aberle recently tested Polks Pow ermax Merlin system receiver 5C455 RC46 its LO low side An IF bandwidth 6 dB 2 kllz claimed nothing quoted 85 kHz Merlin performance meets AMA guide lines except ins LO wrong side does use dual conversion DC outper formed 1991 DC system have tested ex cept its PCM computer slow April 1989 141 LONE STAR MODELS1412 1623 S7th St Lubbock TX 79412 cant 46 Handling charge pay UPS Add $250 COD $300 extra PP APO FPO StateS accept Vs4 Master Card personal checks COO 6% 368/n TenaS US crrency Mnmom Wood Order 51000 I WANNA RACE NORTHEAST AREA A 5- BEGINNER RACES 0-500 * FORM-i * FAI Instructions Club Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVEFRANKLIN MASS 02038 Tel 617 528-4043 203 673-2000 control transmitter 200 ft away can lay RC44 RC48 transmitter antenna right re ceiver antenna driving Merlin PCM system fail-safe Under same conditions can bring RC23 45 47 transmitter within 12 ft receiver before causing fail safe think clearly demonstrates narrow-band SC455 can made work well direct interference transmitter 23 channels away no worse indirect interference Tx channel away youve got nothing worry about AMA has protected OWBAMs long time its carefully selected even-numbered channelshut protection never absolute Now enlightened self-interest forces AMA move better things Prediction #1 Wideband SC4SS receivers will much use 72 MHz Aircraft Only band after 1991 will generally use ful 75 MHz Non-Aircraft Only band either 30 channels used Narrow-band SC455s will work right chan nels however keep telling THE KEY TO THE FU TURE IS GOOD RECEIVER test re sults quoted next section will demonstrate manufacturers have responded challenge good receivers now avail able additional study see AMA Phase-In Plan Explained April 1984 edition AMA News pages 103-104 Continued next month Mods/Berman Continued page 41 swivel-neck because couldnt see straight over tail-draggers nose models fa vor such gear arrangement flying grass fields because tail-draggers rear apex triangle seems provide better ground handling stability nose wheel setup Hence Gerry Terry Grahams Akrobat H tail-dragger sort -scale Laser 200 tempted another desirable building proj ect Examining tail wheel arrangement Akrobat II plans though soon wriniding nose yes feeling unmistakable stirrings urge mod probability Grahams original tail wheel functions perfectly well designed revisions II must confess did wasnt good company Didnt such illustrious aircraft British Comet Lockheed Electra others have design flaws over come degrees rate Akrobat tail wheel Mark III emerged successfully design works leads useful life today sembly shown photo well beyond its 100th contact earth Steering remarkably effective manufactured unit out 040 dural aluminum mooched local fixed base operator Please note shaded area sketch cut away after bending U rather before coping saw fine teeth will job competently Probably qualifying drastic mod forced upon original Hots first seen July 1986 issue Model Airplane News overall de sign very much appealed still lot quibbles An almost 5-ft-wingspan model one-piece structure An inacces sible fuel tank Two aileron servos such relatively small plane aile rons conveniently abut fuselage didnt bother send fullsize plansjust wound up old cerebral escapement struck pencil sheet paper modification evolved seemed satisfy previous objections Rather jamming fuselage servos bottom wing Mark IH would have very slightly fatter belly af fording comfortable mounting space wing would bolt above have single servo actuating both ailerons through torque rods removable top hatch would allow wing demounting also clear space fuel tank removal should become necessary Since unable buy shaped solid aileron stock suitable dimension con structed built-up ailerons 42 balsa little triangular ribs finished prod uct turned out unbelievably rigid worked out splendidly old fat wings will soon celebrate its second birth142 Model Aviation
Edition: Model Aviation - 1989/04
Page Numbers: 36, 37, 141, 142
George Myers Radio Thchnique 70 Frodilkh Farm Rd Hkksville NY 11801 ABSTRACT Predicted 1991 operating condi tions whether AMA goes 50 channels Part 1 Single-conversion receivers WHATS AHEAD recently received letter Dear George just recently joined AMA am now wor tying about 1991 specifications radio Will able use 1988 name deleted AM radio equipment matter other non 1991 equipment after 1991 Will manufacturers continue offer cheaper line radios like four channels $100 am very confused s/Jim Hobelsberger 2956 Kelly Rd La Cres cent MN 55947 answer him follows Dear Jim First important 1988 system has narrow-band transmitter Tx pretty good receiver Rx will work through 1991 beyond people confusing probably have older equipment isnt good yours Now lets look situation folks old equipment am lawyer legal advice way understand situation Equipment manufactured Type Acceptance certificate issued manufacturer FCC can legally used RC flying long 50 Aircraft Only 72 MHz chan nels six models 27 MHz channels ap proved RC use FCC have Amateur Radio Operators license can fly ten 50 MHz eight 53 MHz channels Thats 74 channels available have right fly Type Accepted equipment until either wears out dispose So can fly what have 1991 beyond difficulty Type Acceptances dont have expiration dates FCC reg ulations change production obsoleted equip ment ceases owner equip ment have no way knowing about know transmitter holding has Type Acceptance sticker Therefore some thing built 1970 under Type Acceptance Type Certification force THEN before cur rent narrow-band channels existed legally us able NOW can see danger cant has talk about asking FCC put time limit legal use obsolete equip ment nothing has come sticking point definition obsolete AMAs program put Gold Silver stickers transmitters has conducted filter out dangerously inadequatebut other wise legalequipment still around credit modelers everywhere under stood what being done reacted respon sibly AMA Radio Guidelines published Membership Manual describe per formance characteristics radios should able work together 50-channel 1991 en vironment might guess anything doesnt conform guidelines obsolete sense could true have re member guidelines FCC regula tions Therefore cant obsolete anything As written 1988 Membership Manual page 11 guidelines little vague about single-conversion receivers will cor rected can ignore guidelines until want fly AMA-sanctioned competition case will need narrow-band transmitter defined AMA Radio Guidelines en ter competition channels RC12 14 16 34 right now Wide-band transmitters accept able channels RC38 40 42 right now Beginning 1991 youll need narrow-band transmitters Gold stickers whatever other documentation AMA requires fly competition channel no distinc tion between AM FMor between PCM other encoding schemesin guidelines FM isnt way go AMA does require narrow-band RE CEIVER competition use time opinion should Until narrow-band receiv ers required AMA Contest Directors must counted schedule use RC channels competition events way minimizes modeler-to-modeler interference taking ac count characteristics receivers currently use None manufacturers representatives 36 Model Aviation Too bad isnt color Larry Bashores Mechanicsburg PA Great Lakes 2T biplane gleams redlwhitelblue paint might prototype Georges next Scale ship plane uses flat-4 Lycoming AEI0-360 engine instead original inverted inline Menasco engine Myers has seen entered Aerobatics competition Jaffrey NH Red Lion NJ Polks Powermax Merlin PCM single-conversion narrow-band receiver free inter ferences will introduced 50 aircraft-only RC channels opened up 1991 PCM computer vital type performance since can reconstruct valid control information previously received signals thereby continuing maintain control face 50% Interferencel Myers has say about radio month Ive spoken reports plan continue pro ducing what used sell stopped producing what would call low-performance equipment five years ago has steady improvement performance equipment offered sale point some cheapest radios 1988 outperform highest priced radios 1982 earlier dont meet AMA guidelines Expect see high-performance narrow-band four- six-channel channel FM setsand/or five-channel FM/PCM setsas everybodys low-cost model immediate future Since practically RC equipment comes Far East price will function US dollars value relative Far East currencies anticipated future price leaders will cost less $200 know AMA plans sanction use 50 aircraft channels 1991 also know some 40 kHz forever sentiment intended prolong use old wideband equipment Let get out crystal ball see what changes operating conditions will result depending plan followed First AMA sanctions even-numbered channels 40 kHz forever FCC al certain assign odd-numbered channels someone else critical point remember 50 channels exclusive us now BUT WE ARE ONLY ACCORDED THE STATUS OF SECONDARY USERS means must accept interferencebut cant give anyif let some other service capture odd channels think cant happen Amateurs have just lost 2 MHz 220 MHz band because FCC believed werent using now accept concept SOME BODY will using 50 channels 1991 first thing consider logically follows fact mathematics radio fre quencies Most single-conversion SC super heterodyne receivers use 455 kHz local oscilla tor LO frequency lets call SC455s Under very specific circumstances following wideband SC455s may see increase interfer ence 50 channels used some body Most old wideband AM OWBAM radios SC455s Direct Interference 1 The 5C455s local oscillator LO frequency almost coincides RC transmitter Tx 23 channels away also almost coincides Common Carrier Tx guys tween RC channels located 22 channels Hz away Whether cause interfer ence depends upon position band interfer ing Tx above below receiver Rx proper ties way avoid bad effects situation build SC455s RC 11-35 LO frequency below Tx frequency SC455s RC36-60 LO above Tx frequencyso long interfere suffer interference other services out side RC band AMA guidelines say opposite written around dual-conversion receivers have no 23-channel problem large number re ceivers exist have LO placed inside RC band accordance guidelines AMA Phase-In Plan masked 23-channel consideration sanctioning use odd-numbered RC channels LO placed correctly SC455s RCll 12 59 60 can interfered Tx Continued page 141 DISCOVER HOW EAS CAN BE 1nfroduczp1 XT-1 Transmitter Tray N BJ ENTERPRISES 1100 Center Street Bsvre Montana 59501 Experience Thrill Toy. XT-1 Transmitter Tray wIth set Gimbal Extenders $350 Postage & Handling TO ORDER CALL 14062654828 Make Flying Breeze April 1989 37 Invisible SvitchTM direct replacement radio on/off switch Und Ye Call Der Svitch Der Svitch on-board magnetic on/off switch radio equipment hides inside fuseiage activated outside included small bar magnet slown above cut awful hoies fuselage. isnt time made Der Syitch Ideal Any RIO Plane Boat Car e Prolects r Flyers Safe use Consumes no power ation free h resistant atible radio Optional red LED lamp installs plane dash wing indicate radio state Simple Install Futaba Airtronics radios order Model 1402 simply unplug on/ott switch plug Der Svitch order Model 1401 use connectors trom old on/off switch instructions supplied Der Syitch includes bar magnet activator shown above ModelDescriptionPrice ea 1401Der Svttch activator no connectors twisted Ieadn$1995 sa l4O1LEDDerSvitch activator no connectors twisted leads option eads tor external LED #1405$2495 ea 1402*Der Svttcb activator connectors br Futaba Airtronics$2495 sa 14O2LED*Der Svitch activstor connectorn tor Futaba Airtronics option leads tor external LED #1405*$2995 sa 1405LED red lamp w/24 twisted leads tor Models 1401 LED 1402LE0$895 sa * ordering Model 1402 14O2LED please specify radio connectortypes Connectors available tor Futaba J Futaba G Airtronics radios order include name address specity models needed include check money order send Ragan/Barker Group 5050 Quorum Drive Suite 741 Dallas Texas 75240 Please add $250 per order cover UPS charges Texas residents add sales tax Credit Card orders call between 900 500 Central Time M-F Please allow 2-4 weeks delivery Patent Pending Dealer Inquiries Invited 4 Introductory Offer. 41 II 41 1t I] iyu 111 E1ii RE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SHEETS 36 48 30 BALSA STICKS 3648 16233 332240 18243 316249 14256 132337 20337 163374931 33234458 37 1835471 45 31636282 55 14373 95 61 516395110 38355124 71 123110155 34 3165191 116455 7648 332470 9456 18 48010666 316493122 75 14411013484 38 4165225139 12 4225261 MATCHED SHEETS 42 3324100 164109 3164120 144131 116 14 116 36 116 12 332 14 332 35 332 12 18 18 18 14 18 36 18 12 316316 316 38 316 12 14 14 14 30 412 14 34 141 516516 3838 3812 3634 381 1212 1234 121 58 55 34 34 Os 10 14 10 12 16 08 11 12 18 11 17 22 16 19 21 34 40 21 27 32 42 52 36 46 56 48 67 16 18 24 16 20 30 24 26 30 44 55 28 37 46 55 70 53 62 78 66 90 BALSA HOT LINE Call 806 745 6394 10am 6pm Central Time BALSA TRIANOL ES 36 25 8830 35 45 55 BALSA PLANKS36 86 0 00 1480 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS36 142 65 143 65 382 83 23120 LONE STAREPOXY 90L sI--S 95 5so598 iSoro598 38 rro598 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 1 32 3 1/203 1163 332 3 183 3 163 143 383 123 343 13 1 164 3 324 184 3164 144 384 124 36 53 53 53 63 77 89 104 122 158 242 335 83 100 115 133 158 236 322 TRAILING EDGE 36 14132 51611439 3811246 12270 INSTANTOLUE 1 o TSck 298 10 750 298 20 T5ck 550 20 150 550 BASSWOOD 316316 31614 31638 31612 31634 1414 1438 1434 3838 3/812 3634 12 1 2 1234 BUNDLE DEALS 28116336695 201164361035 20332 336865 15332 436955 151/8336738 101/8436895 15318336920 10316436835 1014336655 101/4436830 103/8336870 53/84 36655 51/2336540 5124361580 10-3324 48885 518448500 5316 4 48600 514448645 48*NEW* 26Hundreds 30 38 46 cessories 60 ishing 42 materials 80 60 #10 SASE 70 atest 90 catalog 100SPRUCE STICKS 3648 18 181725 18 142026 18 3/822 32 316316 28 38 14 3/84055 14 124585 3/8 3/84969 38 126577 12 I/O6688 12347597 SPRUCE TRIANGLES 38 38 12 1 2 34 34 1846 18412 146 HARD MAPLE 1 4 36 3838 38 12 3834 1 2 IRCH DOWELS 18 316 14 516 38 18 40 45 50 58 68 36 09 11 14 25 32 3PiVBIRCH48 16412620 13212445 11612455 1812485 SPLVBIRCH 48 33212588 1/812 625 36316 12625 4714 12828 8438 12725 8112 12900 LITE PLY 48GROOVED LGMOUNTS lllachea 15538341840 3153834/532140 2501234916/45 495 V. Push-Pull/Masters Continued page 137 prop author owned full-scale Lake Amphibian pusher years found protecting propeller loose nuts bolts fishing rods always major concern twin engine push-pull arrangement especially vulner able front prop can kick up stones starter cables wiping cloths etc promptly present rear prop digestion Flying twin pusher also requires special watchfulness flight Push-Pull 240 near-fiasco Immediately after takeoff carburetor aft engine came loose moved pusher prop promptly seif-destructed en gine full bore extremely unbalanced tore itself firewallbefore fuel starvation saved day whole scenario lasted about three four seconds pilot Ray Doan brought ship back single engine thorough preflight check would have spared pusher prop main thing remember get Push-Pull smoothly aloft advance throttles steadily during takeoff Ground control will positive no torque cor rection required Clinibout will solid watch slice through ether sound twin 40s something else Radio Technique/Myers Continued page 37 RC34 through RC37 vice versa 2 next condition change comes out mathematics frequencies coo Image interfer ence will return few SC455s Some folks will remember 7296 Y/W used image 7208 Bn/W Well SC455s RCll-14 RC57-60 can af fected Tx within band have local oscillator wrong side assume manufacturers simply wont sell SC455s channels Besides image coincides exactly Common Car rier Tx frequencies RC Tx helps Rx low LO have possibility imaging TV4 RC44 problem know love So see nothing simple cure above simple Use dual conversion Rx entry-level RC system almost always uses SC455 manufacturers will have narrow-band pay attention proper LO signments keep off RCll 12 13 14 34 35 36 37 57 58 59 60 Jim didnt mention channel doubt above manufacturers just arent selling Indirect Interference condition comes out numbers called Second Order Intermodulation Product Interfer ence 21M generated ANY PAIR Tx operating 23 RC channel numbers apart difference two frequencies modu lated 460 kHz signal often goes right through 5C455 detected interference Think 21M generated JUST ONE PAIR Tx might hit OWBAM SC45Ss SO channels simultaneously including own Rx depending signal strength Rx tenna RECEIVER CHARACTERIS TICS Nobody uses odd-numbered RC chan nels RCll 13 15 today dont see 21M Can predict what will happen give 25 odd-numbered channels another service Now remember discussing RE CEIVER problems assumption everyone already using Gold-stickered narrowband transmitters Practically Tx built since 1987 good enough warrant sticker easiest way avoid problems listed above use dual-conversion receiver dont have block out ANY channels Jim manufacturer offers best dual-conversion receivers market relatively cheap recommend letter appropriate person named end last months column narrow-band 5C455 can work cause interferences discussed above z off 455 kHz intermediate frequency IF dead like 31M Narrow-band SC455s exist example Bob Aberle recently tested Polks Pow ermax Merlin system receiver 5C455 RC46 its LO low side An IF bandwidth 6 dB 2 kllz claimed nothing quoted 85 kHz Merlin performance meets AMA guide lines except ins LO wrong side does use dual conversion DC outper formed 1991 DC system have tested ex cept its PCM computer slow April 1989 141 LONE STAR MODELS1412 1623 S7th St Lubbock TX 79412 cant 46 Handling charge pay UPS Add $250 COD $300 extra PP APO FPO StateS accept Vs4 Master Card personal checks COO 6% 368/n TenaS US crrency Mnmom Wood Order 51000 I WANNA RACE NORTHEAST AREA A 5- BEGINNER RACES 0-500 * FORM-i * FAI Instructions Club Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVEFRANKLIN MASS 02038 Tel 617 528-4043 203 673-2000 control transmitter 200 ft away can lay RC44 RC48 transmitter antenna right re ceiver antenna driving Merlin PCM system fail-safe Under same conditions can bring RC23 45 47 transmitter within 12 ft receiver before causing fail safe think clearly demonstrates narrow-band SC455 can made work well direct interference transmitter 23 channels away no worse indirect interference Tx channel away youve got nothing worry about AMA has protected OWBAMs long time its carefully selected even-numbered channelshut protection never absolute Now enlightened self-interest forces AMA move better things Prediction #1 Wideband SC4SS receivers will much use 72 MHz Aircraft Only band after 1991 will generally use ful 75 MHz Non-Aircraft Only band either 30 channels used Narrow-band SC455s will work right chan nels however keep telling THE KEY TO THE FU TURE IS GOOD RECEIVER test re sults quoted next section will demonstrate manufacturers have responded challenge good receivers now avail able additional study see AMA Phase-In Plan Explained April 1984 edition AMA News pages 103-104 Continued next month Mods/Berman Continued page 41 swivel-neck because couldnt see straight over tail-draggers nose models fa vor such gear arrangement flying grass fields because tail-draggers rear apex triangle seems provide better ground handling stability nose wheel setup Hence Gerry Terry Grahams Akrobat H tail-dragger sort -scale Laser 200 tempted another desirable building proj ect Examining tail wheel arrangement Akrobat II plans though soon wriniding nose yes feeling unmistakable stirrings urge mod probability Grahams original tail wheel functions perfectly well designed revisions II must confess did wasnt good company Didnt such illustrious aircraft British Comet Lockheed Electra others have design flaws over come degrees rate Akrobat tail wheel Mark III emerged successfully design works leads useful life today sembly shown photo well beyond its 100th contact earth Steering remarkably effective manufactured unit out 040 dural aluminum mooched local fixed base operator Please note shaded area sketch cut away after bending U rather before coping saw fine teeth will job competently Probably qualifying drastic mod forced upon original Hots first seen July 1986 issue Model Airplane News overall de sign very much appealed still lot quibbles An almost 5-ft-wingspan model one-piece structure An inacces sible fuel tank Two aileron servos such relatively small plane aile rons conveniently abut fuselage didnt bother send fullsize plansjust wound up old cerebral escapement struck pencil sheet paper modification evolved seemed satisfy previous objections Rather jamming fuselage servos bottom wing Mark IH would have very slightly fatter belly af fording comfortable mounting space wing would bolt above have single servo actuating both ailerons through torque rods removable top hatch would allow wing demounting also clear space fuel tank removal should become necessary Since unable buy shaped solid aileron stock suitable dimension con structed built-up ailerons 42 balsa little triangular ribs finished prod uct turned out unbelievably rigid worked out splendidly old fat wings will soon celebrate its second birth142 Model Aviation
Edition: Model Aviation - 1989/04
Page Numbers: 36, 37, 141, 142
George Myers Radio Thchnique 70 Frodilkh Farm Rd Hkksville NY 11801 ABSTRACT Predicted 1991 operating condi tions whether AMA goes 50 channels Part 1 Single-conversion receivers WHATS AHEAD recently received letter Dear George just recently joined AMA am now wor tying about 1991 specifications radio Will able use 1988 name deleted AM radio equipment matter other non 1991 equipment after 1991 Will manufacturers continue offer cheaper line radios like four channels $100 am very confused s/Jim Hobelsberger 2956 Kelly Rd La Cres cent MN 55947 answer him follows Dear Jim First important 1988 system has narrow-band transmitter Tx pretty good receiver Rx will work through 1991 beyond people confusing probably have older equipment isnt good yours Now lets look situation folks old equipment am lawyer legal advice way understand situation Equipment manufactured Type Acceptance certificate issued manufacturer FCC can legally used RC flying long 50 Aircraft Only 72 MHz chan nels six models 27 MHz channels ap proved RC use FCC have Amateur Radio Operators license can fly ten 50 MHz eight 53 MHz channels Thats 74 channels available have right fly Type Accepted equipment until either wears out dispose So can fly what have 1991 beyond difficulty Type Acceptances dont have expiration dates FCC reg ulations change production obsoleted equip ment ceases owner equip ment have no way knowing about know transmitter holding has Type Acceptance sticker Therefore some thing built 1970 under Type Acceptance Type Certification force THEN before cur rent narrow-band channels existed legally us able NOW can see danger cant has talk about asking FCC put time limit legal use obsolete equip ment nothing has come sticking point definition obsolete AMAs program put Gold Silver stickers transmitters has conducted filter out dangerously inadequatebut other wise legalequipment still around credit modelers everywhere under stood what being done reacted respon sibly AMA Radio Guidelines published Membership Manual describe per formance characteristics radios should able work together 50-channel 1991 en vironment might guess anything doesnt conform guidelines obsolete sense could true have re member guidelines FCC regula tions Therefore cant obsolete anything As written 1988 Membership Manual page 11 guidelines little vague about single-conversion receivers will cor rected can ignore guidelines until want fly AMA-sanctioned competition case will need narrow-band transmitter defined AMA Radio Guidelines en ter competition channels RC12 14 16 34 right now Wide-band transmitters accept able channels RC38 40 42 right now Beginning 1991 youll need narrow-band transmitters Gold stickers whatever other documentation AMA requires fly competition channel no distinc tion between AM FMor between PCM other encoding schemesin guidelines FM isnt way go AMA does require narrow-band RE CEIVER competition use time opinion should Until narrow-band receiv ers required AMA Contest Directors must counted schedule use RC channels competition events way minimizes modeler-to-modeler interference taking ac count characteristics receivers currently use None manufacturers representatives 36 Model Aviation Too bad isnt color Larry Bashores Mechanicsburg PA Great Lakes 2T biplane gleams redlwhitelblue paint might prototype Georges next Scale ship plane uses flat-4 Lycoming AEI0-360 engine instead original inverted inline Menasco engine Myers has seen entered Aerobatics competition Jaffrey NH Red Lion NJ Polks Powermax Merlin PCM single-conversion narrow-band receiver free inter ferences will introduced 50 aircraft-only RC channels opened up 1991 PCM computer vital type performance since can reconstruct valid control information previously received signals thereby continuing maintain control face 50% Interferencel Myers has say about radio month Ive spoken reports plan continue pro ducing what used sell stopped producing what would call low-performance equipment five years ago has steady improvement performance equipment offered sale point some cheapest radios 1988 outperform highest priced radios 1982 earlier dont meet AMA guidelines Expect see high-performance narrow-band four- six-channel channel FM setsand/or five-channel FM/PCM setsas everybodys low-cost model immediate future Since practically RC equipment comes Far East price will function US dollars value relative Far East currencies anticipated future price leaders will cost less $200 know AMA plans sanction use 50 aircraft channels 1991 also know some 40 kHz forever sentiment intended prolong use old wideband equipment Let get out crystal ball see what changes operating conditions will result depending plan followed First AMA sanctions even-numbered channels 40 kHz forever FCC al certain assign odd-numbered channels someone else critical point remember 50 channels exclusive us now BUT WE ARE ONLY ACCORDED THE STATUS OF SECONDARY USERS means must accept interferencebut cant give anyif let some other service capture odd channels think cant happen Amateurs have just lost 2 MHz 220 MHz band because FCC believed werent using now accept concept SOME BODY will using 50 channels 1991 first thing consider logically follows fact mathematics radio fre quencies Most single-conversion SC super heterodyne receivers use 455 kHz local oscilla tor LO frequency lets call SC455s Under very specific circumstances following wideband SC455s may see increase interfer ence 50 channels used some body Most old wideband AM OWBAM radios SC455s Direct Interference 1 The 5C455s local oscillator LO frequency almost coincides RC transmitter Tx 23 channels away also almost coincides Common Carrier Tx guys tween RC channels located 22 channels Hz away Whether cause interfer ence depends upon position band interfer ing Tx above below receiver Rx proper ties way avoid bad effects situation build SC455s RC 11-35 LO frequency below Tx frequency SC455s RC36-60 LO above Tx frequencyso long interfere suffer interference other services out side RC band AMA guidelines say opposite written around dual-conversion receivers have no 23-channel problem large number re ceivers exist have LO placed inside RC band accordance guidelines AMA Phase-In Plan masked 23-channel consideration sanctioning use odd-numbered RC channels LO placed correctly SC455s RCll 12 59 60 can interfered Tx Continued page 141 DISCOVER HOW EAS CAN BE 1nfroduczp1 XT-1 Transmitter Tray N BJ ENTERPRISES 1100 Center Street Bsvre Montana 59501 Experience Thrill Toy. XT-1 Transmitter Tray wIth set Gimbal Extenders $350 Postage & Handling TO ORDER CALL 14062654828 Make Flying Breeze April 1989 37 Invisible SvitchTM direct replacement radio on/off switch Und Ye Call Der Svitch Der Svitch on-board magnetic on/off switch radio equipment hides inside fuseiage activated outside included small bar magnet slown above cut awful hoies fuselage. isnt time made Der Syitch Ideal Any RIO Plane Boat Car e Prolects r Flyers Safe use Consumes no power ation free h resistant atible radio Optional red LED lamp installs plane dash wing indicate radio state Simple Install Futaba Airtronics radios order Model 1402 simply unplug on/ott switch plug Der Svitch order Model 1401 use connectors trom old on/off switch instructions supplied Der Syitch includes bar magnet activator shown above ModelDescriptionPrice ea 1401Der Svttch activator no connectors twisted Ieadn$1995 sa l4O1LEDDerSvitch activator no connectors twisted leads option eads tor external LED #1405$2495 ea 1402*Der Svttcb activator connectors br Futaba Airtronics$2495 sa 14O2LED*Der Svitch activstor connectorn tor Futaba Airtronics option leads tor external LED #1405*$2995 sa 1405LED red lamp w/24 twisted leads tor Models 1401 LED 1402LE0$895 sa * ordering Model 1402 14O2LED please specify radio connectortypes Connectors available tor Futaba J Futaba G Airtronics radios order include name address specity models needed include check money order send Ragan/Barker Group 5050 Quorum Drive Suite 741 Dallas Texas 75240 Please add $250 per order cover UPS charges Texas residents add sales tax Credit Card orders call between 900 500 Central Time M-F Please allow 2-4 weeks delivery Patent Pending Dealer Inquiries Invited 4 Introductory Offer. 41 II 41 1t I] iyu 111 E1ii RE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SHEETS 36 48 30 BALSA STICKS 3648 16233 332240 18243 316249 14256 132337 20337 163374931 33234458 37 1835471 45 31636282 55 14373 95 61 516395110 38355124 71 123110155 34 3165191 116455 7648 332470 9456 18 48010666 316493122 75 14411013484 38 4165225139 12 4225261 MATCHED SHEETS 42 3324100 164109 3164120 144131 116 14 116 36 116 12 332 14 332 35 332 12 18 18 18 14 18 36 18 12 316316 316 38 316 12 14 14 14 30 412 14 34 141 516516 3838 3812 3634 381 1212 1234 121 58 55 34 34 Os 10 14 10 12 16 08 11 12 18 11 17 22 16 19 21 34 40 21 27 32 42 52 36 46 56 48 67 16 18 24 16 20 30 24 26 30 44 55 28 37 46 55 70 53 62 78 66 90 BALSA HOT LINE Call 806 745 6394 10am 6pm Central Time BALSA TRIANOL ES 36 25 8830 35 45 55 BALSA PLANKS36 86 0 00 1480 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS36 142 65 143 65 382 83 23120 LONE STAREPOXY 90L sI--S 95 5so598 iSoro598 38 rro598 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 1 32 3 1/203 1163 332 3 183 3 163 143 383 123 343 13 1 164 3 324 184 3164 144 384 124 36 53 53 53 63 77 89 104 122 158 242 335 83 100 115 133 158 236 322 TRAILING EDGE 36 14132 51611439 3811246 12270 INSTANTOLUE 1 o TSck 298 10 750 298 20 T5ck 550 20 150 550 BASSWOOD 316316 31614 31638 31612 31634 1414 1438 1434 3838 3/812 3634 12 1 2 1234 BUNDLE DEALS 28116336695 201164361035 20332 336865 15332 436955 151/8336738 101/8436895 15318336920 10316436835 1014336655 101/4436830 103/8336870 53/84 36655 51/2336540 5124361580 10-3324 48885 518448500 5316 4 48600 514448645 48*NEW* 26Hundreds 30 38 46 cessories 60 ishing 42 materials 80 60 #10 SASE 70 atest 90 catalog 100SPRUCE STICKS 3648 18 181725 18 142026 18 3/822 32 316316 28 38 14 3/84055 14 124585 3/8 3/84969 38 126577 12 I/O6688 12347597 SPRUCE TRIANGLES 38 38 12 1 2 34 34 1846 18412 146 HARD MAPLE 1 4 36 3838 38 12 3834 1 2 IRCH DOWELS 18 316 14 516 38 18 40 45 50 58 68 36 09 11 14 25 32 3PiVBIRCH48 16412620 13212445 11612455 1812485 SPLVBIRCH 48 33212588 1/812 625 36316 12625 4714 12828 8438 12725 8112 12900 LITE PLY 48GROOVED LGMOUNTS lllachea 15538341840 3153834/532140 2501234916/45 495 V. Push-Pull/Masters Continued page 137 prop author owned full-scale Lake Amphibian pusher years found protecting propeller loose nuts bolts fishing rods always major concern twin engine push-pull arrangement especially vulner able front prop can kick up stones starter cables wiping cloths etc promptly present rear prop digestion Flying twin pusher also requires special watchfulness flight Push-Pull 240 near-fiasco Immediately after takeoff carburetor aft engine came loose moved pusher prop promptly seif-destructed en gine full bore extremely unbalanced tore itself firewallbefore fuel starvation saved day whole scenario lasted about three four seconds pilot Ray Doan brought ship back single engine thorough preflight check would have spared pusher prop main thing remember get Push-Pull smoothly aloft advance throttles steadily during takeoff Ground control will positive no torque cor rection required Clinibout will solid watch slice through ether sound twin 40s something else Radio Technique/Myers Continued page 37 RC34 through RC37 vice versa 2 next condition change comes out mathematics frequencies coo Image interfer ence will return few SC455s Some folks will remember 7296 Y/W used image 7208 Bn/W Well SC455s RCll-14 RC57-60 can af fected Tx within band have local oscillator wrong side assume manufacturers simply wont sell SC455s channels Besides image coincides exactly Common Car rier Tx frequencies RC Tx helps Rx low LO have possibility imaging TV4 RC44 problem know love So see nothing simple cure above simple Use dual conversion Rx entry-level RC system almost always uses SC455 manufacturers will have narrow-band pay attention proper LO signments keep off RCll 12 13 14 34 35 36 37 57 58 59 60 Jim didnt mention channel doubt above manufacturers just arent selling Indirect Interference condition comes out numbers called Second Order Intermodulation Product Interfer ence 21M generated ANY PAIR Tx operating 23 RC channel numbers apart difference two frequencies modu lated 460 kHz signal often goes right through 5C455 detected interference Think 21M generated JUST ONE PAIR Tx might hit OWBAM SC45Ss SO channels simultaneously including own Rx depending signal strength Rx tenna RECEIVER CHARACTERIS TICS Nobody uses odd-numbered RC chan nels RCll 13 15 today dont see 21M Can predict what will happen give 25 odd-numbered channels another service Now remember discussing RE CEIVER problems assumption everyone already using Gold-stickered narrowband transmitters Practically Tx built since 1987 good enough warrant sticker easiest way avoid problems listed above use dual-conversion receiver dont have block out ANY channels Jim manufacturer offers best dual-conversion receivers market relatively cheap recommend letter appropriate person named end last months column narrow-band 5C455 can work cause interferences discussed above z off 455 kHz intermediate frequency IF dead like 31M Narrow-band SC455s exist example Bob Aberle recently tested Polks Pow ermax Merlin system receiver 5C455 RC46 its LO low side An IF bandwidth 6 dB 2 kllz claimed nothing quoted 85 kHz Merlin performance meets AMA guide lines except ins LO wrong side does use dual conversion DC outper formed 1991 DC system have tested ex cept its PCM computer slow April 1989 141 LONE STAR MODELS1412 1623 S7th St Lubbock TX 79412 cant 46 Handling charge pay UPS Add $250 COD $300 extra PP APO FPO StateS accept Vs4 Master Card personal checks COO 6% 368/n TenaS US crrency Mnmom Wood Order 51000 I WANNA RACE NORTHEAST AREA A 5- BEGINNER RACES 0-500 * FORM-i * FAI Instructions Club Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVEFRANKLIN MASS 02038 Tel 617 528-4043 203 673-2000 control transmitter 200 ft away can lay RC44 RC48 transmitter antenna right re ceiver antenna driving Merlin PCM system fail-safe Under same conditions can bring RC23 45 47 transmitter within 12 ft receiver before causing fail safe think clearly demonstrates narrow-band SC455 can made work well direct interference transmitter 23 channels away no worse indirect interference Tx channel away youve got nothing worry about AMA has protected OWBAMs long time its carefully selected even-numbered channelshut protection never absolute Now enlightened self-interest forces AMA move better things Prediction #1 Wideband SC4SS receivers will much use 72 MHz Aircraft Only band after 1991 will generally use ful 75 MHz Non-Aircraft Only band either 30 channels used Narrow-band SC455s will work right chan nels however keep telling THE KEY TO THE FU TURE IS GOOD RECEIVER test re sults quoted next section will demonstrate manufacturers have responded challenge good receivers now avail able additional study see AMA Phase-In Plan Explained April 1984 edition AMA News pages 103-104 Continued next month Mods/Berman Continued page 41 swivel-neck because couldnt see straight over tail-draggers nose models fa vor such gear arrangement flying grass fields because tail-draggers rear apex triangle seems provide better ground handling stability nose wheel setup Hence Gerry Terry Grahams Akrobat H tail-dragger sort -scale Laser 200 tempted another desirable building proj ect Examining tail wheel arrangement Akrobat II plans though soon wriniding nose yes feeling unmistakable stirrings urge mod probability Grahams original tail wheel functions perfectly well designed revisions II must confess did wasnt good company Didnt such illustrious aircraft British Comet Lockheed Electra others have design flaws over come degrees rate Akrobat tail wheel Mark III emerged successfully design works leads useful life today sembly shown photo well beyond its 100th contact earth Steering remarkably effective manufactured unit out 040 dural aluminum mooched local fixed base operator Please note shaded area sketch cut away after bending U rather before coping saw fine teeth will job competently Probably qualifying drastic mod forced upon original Hots first seen July 1986 issue Model Airplane News overall de sign very much appealed still lot quibbles An almost 5-ft-wingspan model one-piece structure An inacces sible fuel tank Two aileron servos such relatively small plane aile rons conveniently abut fuselage didnt bother send fullsize plansjust wound up old cerebral escapement struck pencil sheet paper modification evolved seemed satisfy previous objections Rather jamming fuselage servos bottom wing Mark IH would have very slightly fatter belly af fording comfortable mounting space wing would bolt above have single servo actuating both ailerons through torque rods removable top hatch would allow wing demounting also clear space fuel tank removal should become necessary Since unable buy shaped solid aileron stock suitable dimension con structed built-up ailerons 42 balsa little triangular ribs finished prod uct turned out unbelievably rigid worked out splendidly old fat wings will soon celebrate its second birth142 Model Aviation