femi

Please guys; i need urgent help; I have lost so far 5 birds to problems of interference on the 72 MHz band here in Nigeria. And today, i crashed fro wm a perfectly tracked flight with my new P51 mustang on maiden. In the past, we thought the problem was due to memory effect on the receiver batteries (NiCaD); i then ordered new batteries, one of which was on board my p51 when it crashed this morning. i have even decided to switch to NiMH batteries instead of NiCaD. I am now sick and tired of losing my birds. I really need to know what to do. please advise; Is 72MHz safe outside the US or do i have to purchase a transmitting system that operates on another band?

turbotb0205

My Feedback: (31)

im not sure about band regulations and or interference over there but

one thing to look at is what gear is inside the plane.. is it nitro? or electric

if nitro do a range test get as far away from the plane as you can engine running full throttle have someone hold it .. point it nose up shake hold it flat shake it
check for aany abnormal reaction.. this must be done while moving the control surfaces in a set pattern so your partner can distinguish abnormalities

if its electric or they as youve lost 5 make sure you have the proper caps on the motors.. do the same above range test only vary the throttle throughout the test
with ELE equipment certain servos can interfier with the reciever as can speed controls "ask me how i know []" so the only surefire way to know that your safe flying is
a long range test of course in the air your plane will have a much greater range BUT if you cant walk at least 100ft away (150ft or more is where i like to see mine) from the plane without loosing control or it acting up then this may be your issue

the thing with servo or esc interference is that it will act normally on the ground but once in the air ... mine always seemed to happen approx 100ft up and 100ft out
then the frequency created by the culprit would override what i was telling it to do

also if its electric are you certain your not overloading the esc's BEC requirements alot of esc's can only deal with 3 servos and the motor some will just simply shut down
when you operate a 4th servo EG your flying nicely go to make a turn that requires all surfaces to move like a turn when you rotate with aileron add elevator and give it a lil rudder
the esc will simply heat up and fail or shut down if it has a thermal cutoff i have run into that once when i didnt read the manual for my esc properly

and last but not least double check the reciever crystal to ensure it is fitted and making good contact if it seems loose.. a little bit of shoe goo over it will secure it to the reciever case and thus stop it from wiggling about and or loosing contact

hope you get it figured out and something here helps you distinguish the culprit

adetoyinbo2

My Feedback: (73)

hi femi

what brand of radio are you using,the type of battery volts,amps.
some radio are not design to work in nigeria due to telecomunication interferances.

femi

Thanks guys for the fast reply; I use a Futaba 6X Super Aniversary Edition form ripmax; Its PCM/PPM selectable (whatever that means); I use a 4.8 V (shared with servo) Ni-cd; Transmiting Frequency: 35 or 40 Mhz Band; Modulation FM/PPM or PCM; Power supplyBattery for Transmitter; 9.6 V (Nicd); Current Drain 18mA; Receiever is R138DF Model with 8 Channels; Recieving frequency: 35 or 40 MHz Band; Intermediate Frequency: 10.7 Mhz, 455kHz;

Hope this info helps; please advise.

adetoyinbo2

My Feedback: (73)

hi,

you have a good setup from futaba.what type of power are you runing ie electric or glow/gas engine?.before each flight,do you perform your range checks.how do you run your reciver antenna wire ?your range check must be minimum 100 feets with your antenna down while on the ground.if not there is problem.
you must look at your battery conditions,at fully charged,since you are using 4.8 volts is it enough to power your reciver by performing laod test.
you also might like to check for frequency interferance in your enviroment, ie power lines, telecomunication in your area shering the same freq.
if you are using glow engine, try to eliminate melta pushrod from your throttle servo to the cab.

jimmy

femi

Thanks Jimmy, its good to know that i have a brother out there in the states who's also a passionate RC Aviator; to start, i always perform a range check; i run a glow engine all the time; and i also set up my recieving system with the antenae fully extended to the vertical fin; i must confess that i've never done a load test before and my suspicions in this respects informed my recent decision to place an order for a Hanger 9 Digital Volt & Current meter and a Digital variable load volt meter. I have also recently placed an order with Hobbypeople.net for a volt watch meter; i agree and now realise that 4.8 volts simply isn't enough to power the system; am now bent on staying off Nicd and switching to NimH batteries. further, here in Nigeria, the only suitable flying field in lagos is arround Ogudu GRA at a large undeveloped land. there are however some telecomunication masts sightable at a distance far out from the field. I am going to have to confirm what frequencies are in operation here in nigeria, but could you confirm if companies like Futaba, Hitec or JR have radios configured for other bands other than 72 MHz.

By and large jimmy, please advise as to complete elcetronic setup that will most like be glitch or interference free, i.e i mean from radio to battries spec and reciever; do i need to upgrade my transmitting & recieving system?

femi

carrellh

You mention the 72 mhz band in multiple posts posts. In post 4, the specs you give list 35 or 40 mhz. You need to determine exactly what you already have before you think about spending money for something else. The crystals will have a tag that lists the frequency.

All of the radio companies make systems on many different bands because many countries have laws regarding what you're allowed to use.

4.8 volt receiver packs are perfectly fine for most applications. You might have a pack that does not supply enough current (amperage) to run everything.

The packs that come with most radios have 600 mah capacity. I buy receiver packs from "NoBS Batteries" that are 4.8 volt, 1650 mah capacity. There is nothing wrong with NiCad batteries. In some cases they are preferred over NiMH. There is good info about this on the NoBS web site.
http://www.hangtimes.com/nobsbatteries.html

adetoyinbo2

My Feedback: (73)

hi femi

pm me at my email address [email protected].

thanks
jimmy

femi

Hi Carrell and jimmy; thanks guys for the advise; Carrell you are right; i checked the manual of my Tx; My futaba6X reciever is on 35MHz Band PPM FM; Whilst my Hitec flash 5X is on 72 MHz Ch.45; I have experienced gliches on both; but in the case of the Hitec, the failsafe mechnism often gives me time to recover or re-aquire signal (that is assumming the configuration of the plane in terms of airspeed and altitude are favourable) I also discovered that on the Futaba 6X, the failsafe mode is only operational in PCM (Pulse Code Modulation) Mode and not in the PPM (Pulse Position Modulation) mode in which i fly owing to the FM PPM reciever that shipped with the system. That means for all intents and purposes, the Futaba has to go.

Carrell, thanks also for the link, it was informative, and am completely disabused of any preconceptions i had against Nicds. However, i am still far from solving the problem; It appears my only recourse now is to research the available frequencies in use locally here in Nigeria, and that will also include radio station frequencies on FM (thats assuming it can/does have an effect). But Nigeria being what it is, it will probably be an uphill task, owing to a general dearth of info on practically everything. But should you know of, or can advise of safe frequencies and channels, please let me know; or if you know of a superb recieving system, please advise; THIS IS CRITICAL, my flying career is at STAKE here.

Thanks, looking forward to getting some help.

femi