There telemetry system display Toledo year appeared provide everything needed very reasonable cost Unfortunately being offered illegal frequencies telemetry fact radio control frequencies could have disaster making Discussion later brought assurance frequency would changed ham frequency thought long licensed Ham turned system off anyone could operate unit Anyway nothing new yet would nice system readily available purpose Some work has done using flyby operationwhere aircraft flown along defined line fifty feet microphone altitude twenty feet Using analyzer third-octave band example accumulate function provides some very good flight data Making data complete just sound level requires engine rpm airspeed Only can say specific propellers silencers will provide provable sound level next time procedures ADD-ON MUFFLER An attempt made past week get some running time temperatures humidity have made life miserable two monthsmost unusual event out field set things up morning before got excessively hot Right Before long first running underway temperature approaching 1000 field did get run up 0S 6 1SF accumulate some data octave band analyzer Unfortunately able run variety propellers have really good set figures time Perhaps weather will begin cool off things will improve Anyway system under test Aspire DuBro Products have overly impressed number add-on units past especially claim size fits Quite often find unit will work fairly well 40 engine certainly too restrictive satisfactory 60 Aspire different breed Photo number shows unit mounted front section OS 744 muffler please note two different mufflers marked 744 having bolt holes different spacing ever order 744 sure specify mounting dimensions Photo number two shows unit mounted SuperTigre 40 have run unit 40 yet Aspire well-engineered unit series steps providing tight seal attachment muffler front section Instructions tell mount unit attachment bolt included inside unit part makes different others two rings neoprene inserts spaced around central part unit using unit 61 engine remove inserts inner ring alters potential back pressure unit prevents loss power increase temperature have changed volume addon unit Mounting unit typical 40 muffler would provide greater percentage increase total muffler capacity compared mounting 40 engine muffler works quite well 61 should better 40 Reading taken analyzer said assembly generating 892 dBA 12750 rpm APC 12 x 7 propeller Simpson meter said 5 dBA higher event readings under conditions below 90 dBA feel confident can run larger props substantially lower reading will seen am impressed Aspire unit works manufacturing assembly excellent probably have problems equipment under 1000 temperatures will wait some cooler air rict Reports columns President Executive Vice 174 Model Aviation ident Executive Director will return next month
Edition: Model Aviation - 1995/12
Page Numbers: 173, 174
There telemetry system display Toledo year appeared provide everything needed very reasonable cost Unfortunately being offered illegal frequencies telemetry fact radio control frequencies could have disaster making Discussion later brought assurance frequency would changed ham frequency thought long licensed Ham turned system off anyone could operate unit Anyway nothing new yet would nice system readily available purpose Some work has done using flyby operationwhere aircraft flown along defined line fifty feet microphone altitude twenty feet Using analyzer third-octave band example accumulate function provides some very good flight data Making data complete just sound level requires engine rpm airspeed Only can say specific propellers silencers will provide provable sound level next time procedures ADD-ON MUFFLER An attempt made past week get some running time temperatures humidity have made life miserable two monthsmost unusual event out field set things up morning before got excessively hot Right Before long first running underway temperature approaching 1000 field did get run up 0S 6 1SF accumulate some data octave band analyzer Unfortunately able run variety propellers have really good set figures time Perhaps weather will begin cool off things will improve Anyway system under test Aspire DuBro Products have overly impressed number add-on units past especially claim size fits Quite often find unit will work fairly well 40 engine certainly too restrictive satisfactory 60 Aspire different breed Photo number shows unit mounted front section OS 744 muffler please note two different mufflers marked 744 having bolt holes different spacing ever order 744 sure specify mounting dimensions Photo number two shows unit mounted SuperTigre 40 have run unit 40 yet Aspire well-engineered unit series steps providing tight seal attachment muffler front section Instructions tell mount unit attachment bolt included inside unit part makes different others two rings neoprene inserts spaced around central part unit using unit 61 engine remove inserts inner ring alters potential back pressure unit prevents loss power increase temperature have changed volume addon unit Mounting unit typical 40 muffler would provide greater percentage increase total muffler capacity compared mounting 40 engine muffler works quite well 61 should better 40 Reading taken analyzer said assembly generating 892 dBA 12750 rpm APC 12 x 7 propeller Simpson meter said 5 dBA higher event readings under conditions below 90 dBA feel confident can run larger props substantially lower reading will seen am impressed Aspire unit works manufacturing assembly excellent probably have problems equipment under 1000 temperatures will wait some cooler air rict Reports columns President Executive Vice 174 Model Aviation ident Executive Director will return next month