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egrave
02-22-2006, 05:12 PM
I have two question one what is the differents between Negative and Postive Shift Recivers. The second question is do I use the same battery for the motor and the recever or do I use two different batterys.

Nitro Blast
02-22-2006, 05:32 PM
I'm no radio expert, but the shift differential is the way the signal is sent to the RX. Its why an Airtronics TX wont work a Futaba RX.

The BEC (battery eliminator circut) is used most commonly when the model is smaller, and the 'step down' chore from the controller to the RX doesnt have to work too hard (as it does with MONDO battery packs)

25~40 size glow models will be great with the BEC 99% of the time, Where as bigger models like my Sportsman Avaition Corsair (60~90 size)carries a battery pack for the servos (5 in total, one a retract servo).

Hope this helped, I learned the BEC lesson just in time to save this airplane!
http://img394.imageshack.us/img394/2994/bigcorsair8tu.jpg

Steve
02-22-2006, 07:30 PM
Nice Corsair Nitro!

They both work the same...just require that the TX and RX are matched and that future systems must match the shift of your TX. IF you like JR equipment, you'll always have positive shift RX. If you like Futaba or Hitec...you'll have negative. They both work equally well.

For you second question it depends on the plane, the number of servos used (and for what purpose) and whether it's an electric or gasser.

Most smaller electrics have he bec built into the ESC which in turn powers the RX and the servos at the same time.

I have two question one what is the differents between Negative and Postive Shift Recivers. The second question is do I use the same battery for the motor and the recever or do I use two different batterys.

raynet11
02-24-2006, 08:02 PM
The newer computer radios can do both positive or negative, well at least I can on my Optic-6 and I wouldn't consider that one of the best radios out there good enough for me though handles planes and helis that's all I want. One isn't any better then the other, I posted this same question a long time ago on rcgroups and never really managed to get a good reply as to what is better, they are like protocols on a computer doing the work in the background you only really notice the end result.

slipstick
02-24-2006, 09:45 PM
Neither shift is better than the other. Having different shifts is just an attempt by the major manufacturers to lock you into their equipment so neither JR or Futaba make shift selectable transmitters e.g. if you buy JR Tx you can't use a Futaba Rx and vice versa (except JR now make at least on of their Rxs in both shifts).

Fortunately all this +/- shift stuff only applies in North America on 72MHz equipment. For those of us in the rest of the RC world all our equipment is on the same shift, so we can mix gear from any manufacturers we choose with no problems (apart from PCM which is another problem altogether).

Steve

AEAJR
03-10-2006, 12:51 PM
Pick the radio you like, then get receivers that work on that shift. Simple as that. Think of this when you are buying receivers and at no other time.

flypaper 2
03-10-2006, 05:01 PM
Nitro Blast:
A little off the subject but I need to pick your brain. I have a Topflite Corsair that I built quite a while ago and I want to convert to electric. What did you use for a power train, motor,ESC,batt.?