transmitter

Hi
This is my first post to this forume. Any body can explain to me the
diference between PCM and PPM transmitter, FM and AM, 35 and 40 Mhz.
I wont to bay a new programable transmitter for helicopter, 6 chanel transmitter is OK for normal flight ? , can you sugest me one.

First, welcome to the forum.

Second, read as much helifever as you can, it's now downloadable in pdf format for bedtime disconnected reading, so easier than ever.


PCM uses an encoded signal to talk to the Rx

Advantages:
Ignores glitches in the radio signal giving a smoother ride. Has a fail safe setting in case the signal from the transmitter is totally lost (this may not save your heli, but should stop the heli hitting someone at full revs if you lose connection)

Disadvantages:
Can mask interference problems caused by heli components ie.high frequency vibration or metal rubbing on metal. Receivers are more expensive.

A PCM radio can be set up to transmit PPM, but not the other way round.

Some people setup and test their helis using a PPM receiver to ensure that the heli isn't interfering with the siganl and then change to PCM to ensure that external glitches don't get through.

I'm pretty sure AM is dead now, but i may be wrong.

35MHz 40 MHz. Your government will have decided which frequencies are permissible in your country. Find out which and then buy accordingly.

6 channel is pretty much the minimum for flying as most gyros need a gain channel to control their sensitivity in flight. The transmitter must be a heli transmitter though unless you want to buy a governor the moment you want to fly upside down.

I bought a JR x378 4 months ago as my first heli radio, it's 7 channel and programmable and not a bad radio but i can see myself wanting something with better programming capabilities soon.

Buy the best (not necessarily most expensive) radio you can afford.

A lot of people rave about hitec / airtronics radio gear, never used it but it does come in a lot cheaper than the JR / Futaba stuff.

Are there any other heli pilots in your area who could help you set stuff up etc.

Russ

Thanks a lott russ for this informations. what you sugest me to by
PCM or PPM?
About the frequency 35 or 40 . I don't now how to decide which one, becouse in my country R/C airplane are not allowed, so I will
tray to flay on my responsability, but tell me what the difference in using 35 or 40 mhz, maybee the signal can interfere with comunication or sumthing like that.

The signal will interfere with any signal at the same frequency.

That said, your transmitter is more likely to be transfered with, as it has a much lower power rating than say a comms mast.

If you are going to fly and can't gaurantee that there is a frequency set aside then PCM is pretty much a must.

Also make sure the military / police etc don't transmit on anything even close to what you're going to buy, even over here they go mental about people messing with their frequencies.

What kind of penalties are there for flying helis over there.

Russ

hey dudes

if flying rc planes is elegal in your country
heli wont be anny different.the reason for this is usaly the fact
that the radios we use have a range of 1.5 kilometers,and a heli can fly over 110 mph.so they fear terorist attacks.try shooting down something that small and that fast,i know this from talking with people in our canadian security agency..

dont spend your cash befor you are absolutly sure it is legal

steff