Whistle Blows Dont Fly Maintaining sound radio contact model ulti mately rests fly monitoring system intended coverthe aspect Third Order Intermodulation rest up U Dennis Tierney IT ALL STARTED Sunday afternoon last fall club adopted recom mended frequency control system several frequencies grouped pin two planes different frequency No else either frequency club rules could nt fly either plane because someone flying yet another frequency decided some investigation purpose behind frequency group ings didnt take long discover terms Second Order Third Order Intermodulation interference magazines talking about results interMarch 1987 93 Comprised mainly sheet metal perf board frequency monitor well suited isolated life flying field Simple diode logic performs and/or decision making J _______________ V K TYPE 9914 ii47k Ft PS 3904 ffl 71 90 ] H r 4I ference testing recommendations flight line spacing frequency usage etc terms explanations werent really too hard understand its bad dont make change work though have come up better way Since didnt have room field box microcomputer started looking hardware way calculate interfering frequencies After test results thanks guys made job lot easier turned out Third Order Intermod major concern short computer program make necessary calculations 2 x fl-fl revealed definite pattern takes two frequencies particular separation interfere third pin board could monitor frequencies use de termine what frequencies prohibited people could fly time solution turned out simple illustrated schematic dont let scare promise took longer draw circuit did build cost minimal switch pin feeds AND gate set offending frequencies turn feed OR gate sound alarm forbidden combinations occur AND gate OR gate basic decision-making parts computer can have few two inputs need AND gates will have three inputs provide output input 1 AND 2 AND 3 active OR gate will have 18 inputs provide output 1 OR 2 OR 3 OR 4 etc active output goes amplifier provide drive buzzer configuration could have bit neater using integrated circuit gate packages require power operate expensive diode arrangement chose though circuit requires bunch diodes 94 Model Aviation Achieve proper contact angle bending switch armature up until -In clearance atthe edge board using toothpick spacer bend back parallel Point-to-point wiring eliminates need printed circuit board Clothespins keep sheet metal switches held normally closed position 9V battery provides power dirt-cheap switches /I6 x 1 -in strips made scrap sheet metal duct work housing top board came same piece Any non-conductive ma terial can used back plate also serves switch insulators frequency flag stickers available Ace RC electronic components come Radio Shack Cut stickers down 1 x 2 cutting off space provided fliers name piece x 2-in ply epoxied wooden clothespin marking channel numbers Spring switch contacts appear normally open respect common bus bars along edge pins hold switches closed board Ihere no switches tor channels 12 eu. iwi au mt rence cant 7296 7564 because enter prrtected against unless know its in-band intermod pattern thLre frequencies however should con- test position test-off-on switch sidered totally safe channels because tests battery condition sounding out-of-band transmitters such radio pag- buzzer long switch systems theres near fieldV Continued page 170 March 1987 95 Full-size Plan List Available complete listing plans previously published magazine through NoX5J3 may obtained free charge writing enclose stampedpre-addressed envelope Model Aviation 1810 Samuel Morse Dr Reston VA 22090 emcee memo come me memo memo CnC2 3PleaseNoCOD2-S -~CD m rnNoteephane j orderse o Q0= -2n O-%-.m20 -cw a F SCN-CCflCfl gm C S p p Ni _ _ I _ _ p i - C 02 Cfl C 0 CA1ca0cocacaw02rJ 3CU CS Npcac3NJC--JI Co Cnp..JCNipwccc0 1st3 C Ca C ciacicrcrCrppCaI 0 ar-jC--Ip S Ca -CCa 0 023 C k CI 5C a02cONicnJwC--J02 p Ca Cfl Ni p Ni t mememeCSCOCOCOS@COC0COCOC azzazuarnuuuuuzuazmaaazflrflllfll faaEaEEEEEEEflmnzaazrmurmrn apmpirmCACACACCUCCACA3haeaanabfldwCtJwCJftJ aata-6M CSti 6CM cern sma ~ajernndJflCa-daiatd-C 33 5 CdMCCCflCCaCaJbaJ am eaeacncca uC7 nj Nji iuaj1g5whZ4 fls Tt ~sitsL4sa rAIjrc- iW a--r&a 4CCfnLniSCtE~ Ac E~fl Ca Ca4CCa-aRtt~Ini4[v32]NH] $nflF ~&ofl . . ~rS RE3 4Cm =FCC~ 3Cgt,Cain. -C CCO- arwtaa a- = -a- CaC5tCa ~1i Ca aaaaW~SflCCa C aa-r-a~a-aa aa-a- i:I1i Caa-CaCBaCoa aa25iCa a-a a1a-a- a- CCCC 1ZtACa- X&Ca~CCa-5wC5i5 - aai ja.SAa-Bao3 osnrcirTh oaa- Caj 5 T55jtCO ,aC aCa ~C5 a- 2arrC4a-i =S~ aCCa 1I-.srazxEta-5a5a ai 2a-a5 SC2CoI5 CCo&a-g -2 IR SNC _~aa-aa- 4 -aCaa$.a.a-aCCWSACnC aw jCaBCC~Ca5 C SWCCI&flCra3 a-Ca C a C-ai-ga a-a ia-i9~3$X$ -m0 Ba iICaia-a lsa ia-CaC NC0C CCCCC SI -5Ca 3122aa-a--a~5-a-s NI 5 5-4. C Ca usa-d Cs 1 a- $afla ~ CaIJiIb aRICa iaS [I a9a 3 CI.. IL __I a : a- 5C C C C C----a::: 5 . soOCaCaflnooo COCa CLOCoCCCJCSCCo a- NCCOCa0CC3- Ca-4OCaN4CCC 0CaJCCCaCa--JCOCaCNCCCCCaCO.&acC CoJ0CCJ ONCOCrOfl -JNCrON4CCCA C CaCoCoCC-CoCoCaCoCoCCJCoN0JCaCoCaCo CCOO4C4-J-J CCCJCC3CCaCOCoCo CC CCoCoC~ CA CCC C Ca Ca CCACACJCCCJ C Ca Ca Ca C CCACCACCOC Ca Ca Can CaCa Ca Ca Cii Ca Ca CCC CCACACCC CCC CCC CCC z z 2 PP P c CD 020 rg U 9 -c Ca CD 0 -- i- -C-i n oi - W CD CD Co Ni ~o CD Co.CD -C--i.01.02 -V a- 0 CD 2- 01 0 2 -a0 0 CO Cl CI Cl Cl 01 H 00 CD 0CD - 0 L -t CCDo~ CDCD~SCDCD 0Ca Ca- 0Q~ o oC 0-2r0-CDCDO-CD CD 32C CD 0 oo2A 0020020 NCC0CDCD E-t tato 1-i 00 0 --0 Cr ow Q%% Ccc Nx t 000 CD -t Co c 020 SC CD --Co N ui e N ui Ni prpr Ni Ni Ni Ni Ni Ni Z J 1 3 3 -. tiC Ca 0 0 Ca Ca tiC p 00fr Ni ag 000O CAna O 2 CD -aCaat aj --050 C-C 2zTh 2 a-~ r CD 0 atO ~ CD ~oCD 00 zCDZCD00- o0-0 Pg~t % 0 cWCD CD C- Oat 00 00-00 atCo CD C I 0-n o -q s-fl CD CD 00 00 C7iQ P C C 0 C 0 0 Cc 5 C 0 C 0 0 CD C 0 C 0 C 57 ag InIzmv 002 CD 0 C C 23 D OCCD5CDCIC0O-CDoCD oo~-&CD s CD -c v r 0 CD OS CD &CD WCDa -a - r-z -ccEL2o p Zo 2 3 o CD CD aB 020-C C o o02 O.-CDOc Dcc C CD C CO CCDcacoCDCDCO3 VCDacp2 a23 0 2cc D CD-Ca- .ffiCD --CD 0 0 o 2J0 CD CD - CD.30 02 CD a-~ - O CD -C~ro S2CDaCDCDCo 0 ECICD-w .CD ZCD D -aS2CD- Ca mu C r U Ni ma t U
Edition: Model Aviation - 1987/03
Page Numbers: 93, 94, 95, 170
Whistle Blows Dont Fly Maintaining sound radio contact model ulti mately rests fly monitoring system intended coverthe aspect Third Order Intermodulation rest up U Dennis Tierney IT ALL STARTED Sunday afternoon last fall club adopted recom mended frequency control system several frequencies grouped pin two planes different frequency No else either frequency club rules could nt fly either plane because someone flying yet another frequency decided some investigation purpose behind frequency group ings didnt take long discover terms Second Order Third Order Intermodulation interference magazines talking about results interMarch 1987 93 Comprised mainly sheet metal perf board frequency monitor well suited isolated life flying field Simple diode logic performs and/or decision making J _______________ V K TYPE 9914 ii47k Ft PS 3904 ffl 71 90 ] H r 4I ference testing recommendations flight line spacing frequency usage etc terms explanations werent really too hard understand its bad dont make change work though have come up better way Since didnt have room field box microcomputer started looking hardware way calculate interfering frequencies After test results thanks guys made job lot easier turned out Third Order Intermod major concern short computer program make necessary calculations 2 x fl-fl revealed definite pattern takes two frequencies particular separation interfere third pin board could monitor frequencies use de termine what frequencies prohibited people could fly time solution turned out simple illustrated schematic dont let scare promise took longer draw circuit did build cost minimal switch pin feeds AND gate set offending frequencies turn feed OR gate sound alarm forbidden combinations occur AND gate OR gate basic decision-making parts computer can have few two inputs need AND gates will have three inputs provide output input 1 AND 2 AND 3 active OR gate will have 18 inputs provide output 1 OR 2 OR 3 OR 4 etc active output goes amplifier provide drive buzzer configuration could have bit neater using integrated circuit gate packages require power operate expensive diode arrangement chose though circuit requires bunch diodes 94 Model Aviation Achieve proper contact angle bending switch armature up until -In clearance atthe edge board using toothpick spacer bend back parallel Point-to-point wiring eliminates need printed circuit board Clothespins keep sheet metal switches held normally closed position 9V battery provides power dirt-cheap switches /I6 x 1 -in strips made scrap sheet metal duct work housing top board came same piece Any non-conductive ma terial can used back plate also serves switch insulators frequency flag stickers available Ace RC electronic components come Radio Shack Cut stickers down 1 x 2 cutting off space provided fliers name piece x 2-in ply epoxied wooden clothespin marking channel numbers Spring switch contacts appear normally open respect common bus bars along edge pins hold switches closed board Ihere no switches tor channels 12 eu. iwi au mt rence cant 7296 7564 because enter prrtected against unless know its in-band intermod pattern thLre frequencies however should con- test position test-off-on switch sidered totally safe channels because tests battery condition sounding out-of-band transmitters such radio pag- buzzer long switch systems theres near fieldV Continued page 170 March 1987 95 Full-size Plan List Available complete listing plans previously published magazine through NoX5J3 may obtained free charge writing enclose stampedpre-addressed envelope Model Aviation 1810 Samuel Morse Dr Reston VA 22090 emcee memo come me memo memo CnC2 3PleaseNoCOD2-S -~CD m rnNoteephane j orderse o Q0= -2n O-%-.m20 -cw a F SCN-CCflCfl gm C S p p Ni _ _ I _ _ p i - C 02 Cfl C 0 CA1ca0cocacaw02rJ 3CU CS Npcac3NJC--JI Co Cnp..JCNipwccc0 1st3 C Ca C ciacicrcrCrppCaI 0 ar-jC--Ip S Ca -CCa 0 023 C k CI 5C a02cONicnJwC--J02 p Ca Cfl Ni p Ni t mememeCSCOCOCOS@COC0COCOC azzazuarnuuuuuzuazmaaazflrflllfll faaEaEEEEEEEflmnzaazrmurmrn apmpirmCACACACCUCCACA3haeaanabfldwCtJwCJftJ aata-6M CSti 6CM cern sma ~ajernndJflCa-daiatd-C 33 5 CdMCCCflCCaCaJbaJ am eaeacncca uC7 nj Nji iuaj1g5whZ4 fls Tt ~sitsL4sa rAIjrc- iW a--r&a 4CCfnLniSCtE~ Ac E~fl Ca Ca4CCa-aRtt~Ini4[v32]NH] $nflF ~&ofl . . ~rS RE3 4Cm =FCC~ 3Cgt,Cain. -C CCO- arwtaa a- = -a- CaC5tCa ~1i Ca aaaaW~SflCCa C aa-r-a~a-aa aa-a- i:I1i Caa-CaCBaCoa aa25iCa a-a a1a-a- a- CCCC 1ZtACa- X&Ca~CCa-5wC5i5 - aai ja.SAa-Bao3 osnrcirTh oaa- Caj 5 T55jtCO ,aC aCa ~C5 a- 2arrC4a-i =S~ aCCa 1I-.srazxEta-5a5a ai 2a-a5 SC2CoI5 CCo&a-g -2 IR SNC _~aa-aa- 4 -aCaa$.a.a-aCCWSACnC aw jCaBCC~Ca5 C SWCCI&flCra3 a-Ca C a C-ai-ga a-a ia-i9~3$X$ -m0 Ba iICaia-a lsa ia-CaC NC0C CCCCC SI -5Ca 3122aa-a--a~5-a-s NI 5 5-4. C Ca usa-d Cs 1 a- $afla ~ CaIJiIb aRICa iaS [I a9a 3 CI.. IL __I a : a- 5C C C C C----a::: 5 . soOCaCaflnooo COCa CLOCoCCCJCSCCo a- NCCOCa0CC3- Ca-4OCaN4CCC 0CaJCCCaCa--JCOCaCNCCCCCaCO.&acC CoJ0CCJ ONCOCrOfl -JNCrON4CCCA C CaCoCoCC-CoCoCaCoCoCCJCoN0JCaCoCaCo CCOO4C4-J-J CCCJCC3CCaCOCoCo CC CCoCoC~ CA CCC C Ca Ca CCACACJCCCJ C Ca Ca Ca C CCACCACCOC Ca Ca Can CaCa Ca Ca Cii Ca Ca CCC CCACACCC CCC CCC CCC z z 2 PP P c CD 020 rg U 9 -c Ca CD 0 -- i- -C-i n oi - W CD CD Co Ni ~o CD Co.CD -C--i.01.02 -V a- 0 CD 2- 01 0 2 -a0 0 CO Cl CI Cl Cl 01 H 00 CD 0CD - 0 L -t CCDo~ CDCD~SCDCD 0Ca Ca- 0Q~ o oC 0-2r0-CDCDO-CD CD 32C CD 0 oo2A 0020020 NCC0CDCD E-t tato 1-i 00 0 --0 Cr ow Q%% Ccc Nx t 000 CD -t Co c 020 SC CD --Co N ui e N ui Ni prpr Ni Ni Ni Ni Ni Ni Z J 1 3 3 -. tiC Ca 0 0 Ca Ca tiC p 00fr Ni ag 000O CAna O 2 CD -aCaat aj --050 C-C 2zTh 2 a-~ r CD 0 atO ~ CD ~oCD 00 zCDZCD00- o0-0 Pg~t % 0 cWCD CD C- Oat 00 00-00 atCo CD C I 0-n o -q s-fl CD CD 00 00 C7iQ P C C 0 C 0 0 Cc 5 C 0 C 0 0 CD C 0 C 0 C 57 ag InIzmv 002 CD 0 C C 23 D OCCD5CDCIC0O-CDoCD oo~-&CD s CD -c v r 0 CD OS CD &CD WCDa -a - r-z -ccEL2o p Zo 2 3 o CD CD aB 020-C C o o02 O.-CDOc Dcc C CD C CO CCDcacoCDCDCO3 VCDacp2 a23 0 2cc D CD-Ca- .ffiCD --CD 0 0 o 2J0 CD CD - CD.30 02 CD a-~ - O CD -C~ro S2CDaCDCDCo 0 ECICD-w .CD ZCD D -aS2CD- Ca mu C r U Ni ma t U
Edition: Model Aviation - 1987/03
Page Numbers: 93, 94, 95, 170
Whistle Blows Dont Fly Maintaining sound radio contact model ulti mately rests fly monitoring system intended coverthe aspect Third Order Intermodulation rest up U Dennis Tierney IT ALL STARTED Sunday afternoon last fall club adopted recom mended frequency control system several frequencies grouped pin two planes different frequency No else either frequency club rules could nt fly either plane because someone flying yet another frequency decided some investigation purpose behind frequency group ings didnt take long discover terms Second Order Third Order Intermodulation interference magazines talking about results interMarch 1987 93 Comprised mainly sheet metal perf board frequency monitor well suited isolated life flying field Simple diode logic performs and/or decision making J _______________ V K TYPE 9914 ii47k Ft PS 3904 ffl 71 90 ] H r 4I ference testing recommendations flight line spacing frequency usage etc terms explanations werent really too hard understand its bad dont make change work though have come up better way Since didnt have room field box microcomputer started looking hardware way calculate interfering frequencies After test results thanks guys made job lot easier turned out Third Order Intermod major concern short computer program make necessary calculations 2 x fl-fl revealed definite pattern takes two frequencies particular separation interfere third pin board could monitor frequencies use de termine what frequencies prohibited people could fly time solution turned out simple illustrated schematic dont let scare promise took longer draw circuit did build cost minimal switch pin feeds AND gate set offending frequencies turn feed OR gate sound alarm forbidden combinations occur AND gate OR gate basic decision-making parts computer can have few two inputs need AND gates will have three inputs provide output input 1 AND 2 AND 3 active OR gate will have 18 inputs provide output 1 OR 2 OR 3 OR 4 etc active output goes amplifier provide drive buzzer configuration could have bit neater using integrated circuit gate packages require power operate expensive diode arrangement chose though circuit requires bunch diodes 94 Model Aviation Achieve proper contact angle bending switch armature up until -In clearance atthe edge board using toothpick spacer bend back parallel Point-to-point wiring eliminates need printed circuit board Clothespins keep sheet metal switches held normally closed position 9V battery provides power dirt-cheap switches /I6 x 1 -in strips made scrap sheet metal duct work housing top board came same piece Any non-conductive ma terial can used back plate also serves switch insulators frequency flag stickers available Ace RC electronic components come Radio Shack Cut stickers down 1 x 2 cutting off space provided fliers name piece x 2-in ply epoxied wooden clothespin marking channel numbers Spring switch contacts appear normally open respect common bus bars along edge pins hold switches closed board Ihere no switches tor channels 12 eu. iwi au mt rence cant 7296 7564 because enter prrtected against unless know its in-band intermod pattern thLre frequencies however should con- test position test-off-on switch sidered totally safe channels because tests battery condition sounding out-of-band transmitters such radio pag- buzzer long switch systems theres near fieldV Continued page 170 March 1987 95 Full-size Plan List Available complete listing plans previously published magazine through NoX5J3 may obtained free charge writing enclose stampedpre-addressed envelope Model Aviation 1810 Samuel Morse Dr Reston VA 22090 emcee memo come me memo memo CnC2 3PleaseNoCOD2-S -~CD m rnNoteephane j orderse o Q0= -2n O-%-.m20 -cw a F SCN-CCflCfl gm C S p p Ni _ _ I _ _ p i - C 02 Cfl C 0 CA1ca0cocacaw02rJ 3CU CS Npcac3NJC--JI Co Cnp..JCNipwccc0 1st3 C Ca C ciacicrcrCrppCaI 0 ar-jC--Ip S Ca -CCa 0 023 C k CI 5C a02cONicnJwC--J02 p Ca Cfl Ni p Ni t mememeCSCOCOCOS@COC0COCOC azzazuarnuuuuuzuazmaaazflrflllfll faaEaEEEEEEEflmnzaazrmurmrn apmpirmCACACACCUCCACA3haeaanabfldwCtJwCJftJ aata-6M CSti 6CM cern sma ~ajernndJflCa-daiatd-C 33 5 CdMCCCflCCaCaJbaJ am eaeacncca uC7 nj Nji iuaj1g5whZ4 fls Tt ~sitsL4sa rAIjrc- iW a--r&a 4CCfnLniSCtE~ Ac E~fl Ca Ca4CCa-aRtt~Ini4[v32]NH] $nflF ~&ofl . . ~rS RE3 4Cm =FCC~ 3Cgt,Cain. -C CCO- arwtaa a- = -a- CaC5tCa ~1i Ca aaaaW~SflCCa C aa-r-a~a-aa aa-a- i:I1i Caa-CaCBaCoa aa25iCa a-a a1a-a- a- CCCC 1ZtACa- X&Ca~CCa-5wC5i5 - aai ja.SAa-Bao3 osnrcirTh oaa- Caj 5 T55jtCO ,aC aCa ~C5 a- 2arrC4a-i =S~ aCCa 1I-.srazxEta-5a5a ai 2a-a5 SC2CoI5 CCo&a-g -2 IR SNC _~aa-aa- 4 -aCaa$.a.a-aCCWSACnC aw jCaBCC~Ca5 C SWCCI&flCra3 a-Ca C a C-ai-ga a-a ia-i9~3$X$ -m0 Ba iICaia-a lsa ia-CaC NC0C CCCCC SI -5Ca 3122aa-a--a~5-a-s NI 5 5-4. C Ca usa-d Cs 1 a- $afla ~ CaIJiIb aRICa iaS [I a9a 3 CI.. IL __I a : a- 5C C C C C----a::: 5 . soOCaCaflnooo COCa CLOCoCCCJCSCCo a- NCCOCa0CC3- Ca-4OCaN4CCC 0CaJCCCaCa--JCOCaCNCCCCCaCO.&acC CoJ0CCJ ONCOCrOfl -JNCrON4CCCA C CaCoCoCC-CoCoCaCoCoCCJCoN0JCaCoCaCo CCOO4C4-J-J CCCJCC3CCaCOCoCo CC CCoCoC~ CA CCC C Ca Ca CCACACJCCCJ C Ca Ca Ca C CCACCACCOC Ca Ca Can CaCa Ca Ca Cii Ca Ca CCC CCACACCC CCC CCC CCC z z 2 PP P c CD 020 rg U 9 -c Ca CD 0 -- i- -C-i n oi - W CD CD Co Ni ~o CD Co.CD -C--i.01.02 -V a- 0 CD 2- 01 0 2 -a0 0 CO Cl CI Cl Cl 01 H 00 CD 0CD - 0 L -t CCDo~ CDCD~SCDCD 0Ca Ca- 0Q~ o oC 0-2r0-CDCDO-CD CD 32C CD 0 oo2A 0020020 NCC0CDCD E-t tato 1-i 00 0 --0 Cr ow Q%% Ccc Nx t 000 CD -t Co c 020 SC CD --Co N ui e N ui Ni prpr Ni Ni Ni Ni Ni Ni Z J 1 3 3 -. tiC Ca 0 0 Ca Ca tiC p 00fr Ni ag 000O CAna O 2 CD -aCaat aj --050 C-C 2zTh 2 a-~ r CD 0 atO ~ CD ~oCD 00 zCDZCD00- o0-0 Pg~t % 0 cWCD CD C- Oat 00 00-00 atCo CD C I 0-n o -q s-fl CD CD 00 00 C7iQ P C C 0 C 0 0 Cc 5 C 0 C 0 0 CD C 0 C 0 C 57 ag InIzmv 002 CD 0 C C 23 D OCCD5CDCIC0O-CDoCD oo~-&CD s CD -c v r 0 CD OS CD &CD WCDa -a - r-z -ccEL2o p Zo 2 3 o CD CD aB 020-C C o o02 O.-CDOc Dcc C CD C CO CCDcacoCDCDCO3 VCDacp2 a23 0 2cc D CD-Ca- .ffiCD --CD 0 0 o 2J0 CD CD - CD.30 02 CD a-~ - O CD -C~ro S2CDaCDCDCo 0 ECICD-w .CD ZCD D -aS2CD- Ca mu C r U Ni ma t U
Edition: Model Aviation - 1987/03
Page Numbers: 93, 94, 95, 170
Whistle Blows Dont Fly Maintaining sound radio contact model ulti mately rests fly monitoring system intended coverthe aspect Third Order Intermodulation rest up U Dennis Tierney IT ALL STARTED Sunday afternoon last fall club adopted recom mended frequency control system several frequencies grouped pin two planes different frequency No else either frequency club rules could nt fly either plane because someone flying yet another frequency decided some investigation purpose behind frequency group ings didnt take long discover terms Second Order Third Order Intermodulation interference magazines talking about results interMarch 1987 93 Comprised mainly sheet metal perf board frequency monitor well suited isolated life flying field Simple diode logic performs and/or decision making J _______________ V K TYPE 9914 ii47k Ft PS 3904 ffl 71 90 ] H r 4I ference testing recommendations flight line spacing frequency usage etc terms explanations werent really too hard understand its bad dont make change work though have come up better way Since didnt have room field box microcomputer started looking hardware way calculate interfering frequencies After test results thanks guys made job lot easier turned out Third Order Intermod major concern short computer program make necessary calculations 2 x fl-fl revealed definite pattern takes two frequencies particular separation interfere third pin board could monitor frequencies use de termine what frequencies prohibited people could fly time solution turned out simple illustrated schematic dont let scare promise took longer draw circuit did build cost minimal switch pin feeds AND gate set offending frequencies turn feed OR gate sound alarm forbidden combinations occur AND gate OR gate basic decision-making parts computer can have few two inputs need AND gates will have three inputs provide output input 1 AND 2 AND 3 active OR gate will have 18 inputs provide output 1 OR 2 OR 3 OR 4 etc active output goes amplifier provide drive buzzer configuration could have bit neater using integrated circuit gate packages require power operate expensive diode arrangement chose though circuit requires bunch diodes 94 Model Aviation Achieve proper contact angle bending switch armature up until -In clearance atthe edge board using toothpick spacer bend back parallel Point-to-point wiring eliminates need printed circuit board Clothespins keep sheet metal switches held normally closed position 9V battery provides power dirt-cheap switches /I6 x 1 -in strips made scrap sheet metal duct work housing top board came same piece Any non-conductive ma terial can used back plate also serves switch insulators frequency flag stickers available Ace RC electronic components come Radio Shack Cut stickers down 1 x 2 cutting off space provided fliers name piece x 2-in ply epoxied wooden clothespin marking channel numbers Spring switch contacts appear normally open respect common bus bars along edge pins hold switches closed board Ihere no switches tor channels 12 eu. iwi au mt rence cant 7296 7564 because enter prrtected against unless know its in-band intermod pattern thLre frequencies however should con- test position test-off-on switch sidered totally safe channels because tests battery condition sounding out-of-band transmitters such radio pag- buzzer long switch systems theres near fieldV Continued page 170 March 1987 95 Full-size Plan List Available complete listing plans previously published magazine through NoX5J3 may obtained free charge writing enclose stampedpre-addressed envelope Model Aviation 1810 Samuel Morse Dr Reston VA 22090 emcee memo come me memo memo CnC2 3PleaseNoCOD2-S -~CD m rnNoteephane j orderse o Q0= -2n O-%-.m20 -cw a F SCN-CCflCfl gm C S p p Ni _ _ I _ _ p i - C 02 Cfl C 0 CA1ca0cocacaw02rJ 3CU CS Npcac3NJC--JI Co Cnp..JCNipwccc0 1st3 C Ca C ciacicrcrCrppCaI 0 ar-jC--Ip S Ca -CCa 0 023 C k CI 5C a02cONicnJwC--J02 p Ca Cfl Ni p Ni t mememeCSCOCOCOS@COC0COCOC azzazuarnuuuuuzuazmaaazflrflllfll faaEaEEEEEEEflmnzaazrmurmrn apmpirmCACACACCUCCACA3haeaanabfldwCtJwCJftJ aata-6M CSti 6CM cern sma ~ajernndJflCa-daiatd-C 33 5 CdMCCCflCCaCaJbaJ am eaeacncca uC7 nj Nji iuaj1g5whZ4 fls Tt ~sitsL4sa rAIjrc- iW a--r&a 4CCfnLniSCtE~ Ac E~fl Ca Ca4CCa-aRtt~Ini4[v32]NH] $nflF ~&ofl . . ~rS RE3 4Cm =FCC~ 3Cgt,Cain. -C CCO- arwtaa a- = -a- CaC5tCa ~1i Ca aaaaW~SflCCa C aa-r-a~a-aa aa-a- i:I1i Caa-CaCBaCoa aa25iCa a-a a1a-a- a- CCCC 1ZtACa- X&Ca~CCa-5wC5i5 - aai ja.SAa-Bao3 osnrcirTh oaa- Caj 5 T55jtCO ,aC aCa ~C5 a- 2arrC4a-i =S~ aCCa 1I-.srazxEta-5a5a ai 2a-a5 SC2CoI5 CCo&a-g -2 IR SNC _~aa-aa- 4 -aCaa$.a.a-aCCWSACnC aw jCaBCC~Ca5 C SWCCI&flCra3 a-Ca C a C-ai-ga a-a ia-i9~3$X$ -m0 Ba iICaia-a lsa ia-CaC NC0C CCCCC SI -5Ca 3122aa-a--a~5-a-s NI 5 5-4. C Ca usa-d Cs 1 a- $afla ~ CaIJiIb aRICa iaS [I a9a 3 CI.. IL __I a : a- 5C C C C C----a::: 5 . soOCaCaflnooo COCa CLOCoCCCJCSCCo a- NCCOCa0CC3- Ca-4OCaN4CCC 0CaJCCCaCa--JCOCaCNCCCCCaCO.&acC CoJ0CCJ ONCOCrOfl -JNCrON4CCCA C CaCoCoCC-CoCoCaCoCoCCJCoN0JCaCoCaCo CCOO4C4-J-J CCCJCC3CCaCOCoCo CC CCoCoC~ CA CCC C Ca Ca CCACACJCCCJ C Ca Ca Ca C CCACCACCOC Ca Ca Can CaCa Ca Ca Cii Ca Ca CCC CCACACCC CCC CCC CCC z z 2 PP P c CD 020 rg U 9 -c Ca CD 0 -- i- -C-i n oi - W CD CD Co Ni ~o CD Co.CD -C--i.01.02 -V a- 0 CD 2- 01 0 2 -a0 0 CO Cl CI Cl Cl 01 H 00 CD 0CD - 0 L -t CCDo~ CDCD~SCDCD 0Ca Ca- 0Q~ o oC 0-2r0-CDCDO-CD CD 32C CD 0 oo2A 0020020 NCC0CDCD E-t tato 1-i 00 0 --0 Cr ow Q%% Ccc Nx t 000 CD -t Co c 020 SC CD --Co N ui e N ui Ni prpr Ni Ni Ni Ni Ni Ni Z J 1 3 3 -. tiC Ca 0 0 Ca Ca tiC p 00fr Ni ag 000O CAna O 2 CD -aCaat aj --050 C-C 2zTh 2 a-~ r CD 0 atO ~ CD ~oCD 00 zCDZCD00- o0-0 Pg~t % 0 cWCD CD C- Oat 00 00-00 atCo CD C I 0-n o -q s-fl CD CD 00 00 C7iQ P C C 0 C 0 0 Cc 5 C 0 C 0 0 CD C 0 C 0 C 57 ag InIzmv 002 CD 0 C C 23 D OCCD5CDCIC0O-CDoCD oo~-&CD s CD -c v r 0 CD OS CD &CD WCDa -a - r-z -ccEL2o p Zo 2 3 o CD CD aB 020-C C o o02 O.-CDOc Dcc C CD C CO CCDcacoCDCDCO3 VCDacp2 a23 0 2cc D CD-Ca- .ffiCD --CD 0 0 o 2J0 CD CD - CD.30 02 CD a-~ - O CD -C~ro S2CDaCDCDCo 0 ECICD-w .CD ZCD D -aS2CD- Ca mu C r U Ni ma t U