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-   RC Radios, Transmitters, Receivers, Servos, gyros (https://www.rcuniverse.com/forum/rc-radios-transmitters-receivers-servos-gyros-157/)
-   -   mid price level radio to purchase (https://www.rcuniverse.com/forum/rc-radios-transmitters-receivers-servos-gyros-157/4621512-mid-price-level-radio-purchase.html)

fun2goman 08-14-2006 11:49 AM

mid price level radio to purchase
 
hello to all. i am going into the heli hobby with a 50 size heli. i need to get a radio i will not out grow. i am willing to spend between $300-500. can any1 give me some advice on which one to get and why. All COMMENTS ARE WELCOMED. thanks to all

BarracudaHockey 08-14-2006 01:40 PM

RE: mid price level radio to purchase
 
Futaba 9CHP Super is an excellent radio, a little cheaper and with less features is the 7CH

You are better off getting the helicopter version of whatever radio you choose.

JR has some good ones as well but to get in the class of a 9c you need a 9303 and thats getting pricey.

Stripes 08-14-2006 06:18 PM

RE: mid price level radio to purchase
 
The 7C will drive you nuts by not handling two elevator servos.

Raylon 08-14-2006 07:57 PM

RE: mid price level radio to purchase
 
Will a JR 7202 work well for this also? I have about the same question, except little less money to spend.

Zeeb 08-15-2006 09:50 AM

RE: mid price level radio to purchase
 
If you want to get a tx for use with your E-Flite heli's as well, you'll need a negative shift tx and JR is positive shift.

I've got my Blade CP setup on my Futaba and all you need to do that is the appropriate crystal for the rx and the programing for the throttle curve/pitch stuff. That's posted with the basic setup for a Futaba 7C on the Blade forum by one of the members... :D

fun2goman 08-15-2006 11:50 AM

RE: mid price level radio to purchase
 
can some1 explain the difference between FM, PCM, and SYNTHESIZED. which would be the best for helis and why? thanks guys.

BarracudaHockey 08-15-2006 12:43 PM

RE: mid price level radio to purchase
 
FM = Freqency Modulation, all 3 of the above use FM

PCM Pulse Coded Modulation, a digital way of encoding the stick position and transmit that data to the reciever. Benefits better noise rejection and interference tollerence but its more expensive.

PPM Pulse Position Modulaton, a analog way of encoding stick position and transmitting it. Cheaper but more suseptable to noise but thats mitigated somewhat by the use of dual conversion recievers.

Its important to know that both PPM and PCM use an FM signal, you will often incorrectly see PPM refered to as FM.

Synthesized = you can change to any channel in the band by manipulating either software or rotary wheels. Advantage is you can fly on other channels if the one you use is in use. Of course you either need a crystal for crystal controlled recievers for the channel you intend to use or a synthesized reciever. Disadvantage=cost.

Synthesized can be used for either ppm or pcm, it sets the channel and doesn't know or care how the information on the carrier is encoded.

Synth sets are nice but you usually need access to the reciever to change the dials or crystal, your best bet is to goto the field you plan on flying at and find out what the popular channels are and get your transmitter on something different.

PCM is probably better for helicopters but many of us fly them on PPM w/o any issues. As for other arguments about interference versus lockout, if the interference is bad enough to drive a pcm reciever into lockout its bad enough to knock a ppm receiver out of the air.

Heres some comprehensive reading on the subject. http://www.torreypinesgulls.org/Radios.htm

Zeeb 08-15-2006 01:24 PM

RE: mid price level radio to purchase
 


ORIGINAL: fun2goman

can some1 explain the difference between FM, PCM, and SYNTHESIZED. which would be the best for helis and why? thanks guys.

Barracudahockey has laid out most of the information you asked about, but I'll throw in a couple of other thoughts.

PCM is brand specific, i.e. you must use the same brand tx and rx for it to work. PPM allows the use of other brands provided they use the same positive or negative shift, i.e. a Futaba tx with a HiTec rx.

I'm not sure about other brands, but Futaba synthesized module equipped tx's don't play well with all other brand negative shift rx's in the PPM mode. I've been told that the synthesized modules for the 9C series are not as finicky, but since I've not tried a synthesized module on my 9C I can't say, but the synthesized module on my 9Z won't play with most other brand PPM rx's that I've tried. It won't run the rx on the Blade CP, won't play with the new HiTec OS5's I use on my foamies, but will play with the little 6 channel HiTec rx I have in a trainer I keep around.


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